This post needs reading in conjunction with – ideally just before – reading Partnerships in Healthcare on dh.org.
Over several decades, most people I know, have, along with me, seen Gary Schwitzer, who runs a Health News Review Substack, as the best reviewer of lay and academic media accounts of health issues. Among Gary’s great skills is an ability to pinpoint how media coverage misses the key points of published research typically over-selling the promise of some breakthrough and neglecting to mention the consequences.
FDA Take One
The media frenzy that followed the FDA panel on SSRIs in pregnancy was always likely to draw Gary’s attention and has.
FDA’s Makary stacks the deck with conflicted expert panels.
His coverage of this was however very different to the material he usually deals with – at least the material I’m aware of. His take on the lay and professional reporting linked to the Panel laid out some of the key themes these accounts share, avoiding, as he says, any comment on content.
The Stacks the Deck post seems similar to me to what I attempted in the comments section following the FDA Panel Unsafe Safety Post, where over 30 lay media takes on the Panel, close to uniformly panning both Panel and Panelists, are hosted – without comment.
There is little need for comment – there is a uniform sameness about the coverage, which gives the impression that several of then are likely to be driven by or written by A.I.
I have not attempted to pull out themes, partly because the media coverage is almost entirely American and I risk misreading what is being said. Gary’s reading of the themes has to be more dependable than mine – but at the moment unless the message is in between the lines, which is quite possible, he seems to me to have missed some points.
I have directed comments from some Europeans, other FDA Panelists, and others and linked them to two dh.org posts, which ran in parallel with the RxISK Unsafe Safety post – FDA Panel SSRIs and Pregnancy and There’s Something About Pregnant Mary. These comments bring out themes that strike non-Americans.
I have also separated the lay media commentary from professional organization inputs. The professional inputs are linked in the comments section after Adam Urato and SSRIs in Pregnancy. The professionals offer to advise FDA and Marty Makary on what FDA and he should be doing and thinking.
Gary’s Substack is illustrated with the logos of some of these professional healthcare organizations like the American College of Obstetricians and Gynecologists (ACOG), the Society of Maternal and Fetal Medicines (SMFM) and others. It is beautifully laid out piece with other great images and is well worth reading.
FDA Take Two
Since the FDA Panel and Gary’s Substack post, we have had a replay of the SSRI and pregnancy media coverage featuring Tylenol and Pregnancy. The same lay media and professional bodies are weighing in with similar themes.
I have attached as comments to this post the links to 6 of these that have come my way along with the full text where I have been able to access the articles.
Partnerships
Gary’s Stacking the Deck post has a dh.org linked – Partnerships in Healthcare. The Partnerships post is essentially written by Pharma rather than me.
My hope was to have Partnerships stand as a complement to all of the above without me having to say anything – other than clarify some details for folk to whom material like this is new.
Partnerships shows the professional and other organizations – the list of Partners – that all pharmaceutical companies reach out to, whether we are talking about autism and SSRIs or autism and Tylenol, or Alzheimer’s Dementia and the latest treatments, or Osteopenia and its treatments.
The lay media are not listed in Partnerships but, on issues like pregnancy, Alzheimer’s and osteoporosis, the New York Times, Washington Post, Wall Street Journal and all sorts of other media can be depended to access groups like ACOG and SMFM or their equivalents in other areas of medicine, along with Women’s Health, Autism Support and other groups in the relevant space.
The seventh and eighth images in Partnerships are key. For some readers, these may be jaw dropping but they should come as no surprise. The only jaw dropping element is seeing something everybody suspects is, but would prefer not to be, going on laid out so brazenly and graphically.
The surprise perhaps is that NYT, The Washington Post and others must know on one level that this is exactly what is going on, but are acting as though nothing like this could possibly be in the background to their reporting.
The lay media reporting as it stands could well have been written by A.I. Surely at some point, NYT, the Washington Post and others (increasingly referred to as legacy media) must realise they will be out of business unless they can grapple with and report on some of the consequences of treatments and not just their promise. Unless the legacies build on feed other than company feed delivered through their Partners or A.I., they look like they are toast – except for their usefulness to companies
FDA Take Three
It should come as no surprise that FDA do not have an outreach operation like the ones companies put a lot of time and money into creating and fostering. An outreach that some might hope could combat what the lay media are fed by company Partners.
It may be more of a surprise, may even sound incredible, that companies might welcome FDA or HHS setting up Panels to review the evidence for SSRI or Tylenol use in pregnancy or linkage to autism.
As things stand, FDA risk providing a talking point that companies can use to their advantage by mobilising their patient groups, professional bodies, politicians and others to splutter indignantly in defence of the rights of women and babes in utero (or patients with dementia, osteoporosis or other conditions affecting women mostly) against – pick your words to describe HHS/FDA.
FDA panels risk de facto working to a company agenda for companies who know that in the midst of all the media noise, mostly defending readers’ rights against FDA, the only things over 90 per cent of readers will retain is the name of the company product and the reader’s constitutional right to access this product or born with a warranty right to use it.
It also works because no matter how much FDA might huff or puff it is companies not FDA who are obliged to issue warnings. For companies it is wonderfully helpful to be able to indicate to courts that FDA have reviewed this problem again and again and have not asked us to change anything. FDA and us – thanks to the legacy media – risk being Rope a Dope victims.
This is fertile ground for a few conspiracy theorists. The material can be mobilized as evidence that rather than being played by companies FDA are deliberately playing into company hands.
Heads we win, Tails you lose.
Put that in your pipe and smoke it as the saying goes.
Postscript 1
Gary and other reviewers appear to have missed an American Psychiatric Association letter to Dr Makary. This will form the basis for two follow up posts developing the perils of letting A.I. or Pharma shape professional messaging.
Postscript 2
Almost coinciding with this post, at a press conference President Trump and his Health Team announced that there were grounds to be cautious about Tylenol. The media gathered to defend Tylenol and many accounts featured a 2024 Swedish study – by Viktor Ahlqvist et al.
This has given rise to a media frenzy reported in the comments linked to this post below.
Viktor A was approached the the media to get his take on the Trump pronouncement. He was interviewed by CNN and video clips feature here rather than in the comments below because links like this don’t work as well in comments
It is worth also visiting Partnerships in Healthcare on DH for another angle on what this struggle playing out in the media might mean – along with comments on the next RxISK post American Psychiatric Association and FDA here.
annie says
Senator Ron Johnson@SenRonJohnson 14h
What do you say to a parent whose perfectly healthy and developing child is vaccinated, runs a high fever, has a seizure, and never speaks another word? All we are asking is for people, doctors, and health officials to have an open mind and help us discover the root causes to prevent future injuries.
https://x.com/SenRonJohnson/status/1965584440412848294
Senator Ron Johnson’s logic can apply to RSV injections, SSRI’s in pregnancy, Tylenol in pregnancy, and any other drug under active consideration.
An ‘open mind’ seems deliberately blocked.
‘Are people, doctors, and health officials’, the legacy media and Medical Organizations, so lock-stepped in propaganda, that safety signals lose their morse code.
‘It’s time for more listening – from disparate parties- and fewer barber shop quartet tunes that fall flat in handpicked harmony.’
One characteristic feature of barbershop harmony is the use of what is known as “snakes” and “swipes”
Did my research, Gary..
Dr. David Healy says
Wall Street Journal: What’s News September 5th
In a report this month, Robert F. Kennedy Jr. plans to announce that pregnant women’s Tylenol use and folate deficiencies are potentially linked to autism.
The Department of Health and Human Services report will also suggest a medicine derived from folate can treat autism symptoms, according to people familiar with the matter. Scientists say conducting rigorous autism research can take years; to date, a variety of possible contributors have been identified. The American College of Obstetricians and Gynecologists says Tylenol is safe but recommends pregnant women consult with their doctors, as with all drugs. Tylenol maker Kenvue denied any causal link between the drug and autism.
Dr. David Healy says
CNN September 5
Upcoming HHS report will link autism to common pain reliever, folate deficiency in pregnancy, Wall Street Journal reports
By Brenda Goodman Deidre McPhillips Sep 5, 2025
An upcoming report from the US Department of Health and Human services is likely to link the development of autism in children to a common over-the-counter pain reliever, and it will reference a form of the vitamin folic acid as a way to reduce symptoms of autism in some people, the Wall Street Journal reported Friday.
The report is said to highlight the pain reliever Tylenol, when taken during pregnancy, along with low levels of folate, a vitamin that is important for proper development of a baby’s brain and spine, as potential causes of autism, according to the Wall Street Journal. It will also name folinic acid, a form of folate also known as leucovorin, as a way to decrease symptoms of autism.
Folate supplements are already recommended for women during pregnancy to prevent neural tube defects, such as spina bifida, in infants.
Tylenol, which is the brand name of the generic pain reliever acetaminophen, is widely used in the US, including during pregnancy. Drugmaker Kenvue said in a statement Friday, “Nothing is more important to us than the health and safety of the people who use our products. We have continuously evaluated the science and continue to believe there is no causal link between acetaminophen use during pregnancy and autism.”
Experts generally agree.
“There is no clear evidence that proves a direct relationship between the prudent use of acetaminophen during pregnancy and fetal developmental issues,” Dr. Christopher Zahn, chief of clinical practice for the American College of Obstetricians and Gynecologists, said in a statement Friday. “Neurodevelopmental disorders, in particular, are multifactorial and very difficult to associate with a singular cause. Pregnant patients should not be frightened away from the many benefits of acetaminophen, which is safe and one of the few options pregnant people have for pain relief.”
The incidence of autism in the US is on the rise. About 1 in every 31 children was diagnosed with autism by age 8 in 2022, up from 1 in 36 in 2020, according to a US Centers for Disease Control and Prevention report published in April.
There are two primary reasons for the increase, according to Dr. Christine Ladd-Acosta, vice director of the Wendy Klagg Center for Autism at John Hopkins.
The first is that the definition of autism was broadened by the psychiatric community in 2013, so more people now qualify for an autism diagnosis.
Secondly, there has been a push for better screening of children, especially babies, for signs of autism. That push for increased awareness of the symptoms has been accompanied by a greater acceptance of the disorder, so people are not as afraid to seek help or to be identified as having autism, Ladd-Acosta said on the Johns Hopkins podcast “Public Health on Call.”
An HHS spokesperson said Friday that the agency is “using gold-standard science to get to the bottom of America’s unprecedented rise in autism rates. Until we release the final report, any claims about its contents are nothing more than speculation.”
Several studies have looked at the association between acetaminophen use in pregnancy and the development of autism in children, but experts say the science behind this theory is not settled.
A 2024 study published in JAMA looked at more than 2 million children born in Sweden between 1995 and 2019, about 185,000 of the whom were born to mothers who used acetaminophen during pregnancy. The study compared autism rates between these children with their siblings and with children who were not exposed, and it found that acetaminophen use during pregnancy was not associated with an increased risk of autism, attention deficit hyperactivity disorder or other neurodevelopmental disorders.
A meta-analysis published in August in the journal BMC Environmental Health looked at 46 studies on the use of acetaminophen during pregnancy and neurodevelopmental disorders in children. Six of the studies looked specifically at acetaminophen and autism. Overall, the analysis concluded that there was “strong evidence of an association” between taking acetaminophen during pregnancy and the development of autism in children, but the authors caution that their paper can show only associations, not that acetaminophen causes autism.
“We recommend judicious acetaminophen use — lowest effective dose, shortest duration — under medical guidance, tailored to individual risk–benefit assessments, rather than a broad limitation,” the researchers wrote.
The US Food and Drug Administration reviewed the risks of certain types of pain relievers during pregnancy in 2015 and said that all the studies it reviewed had methodological flaws. As a result, the agency said it would not change its recommendations for pain medications during pregnancy at that time.
The Society for Maternal-Fetal Medicine also reviewed the issue in 2017. It concluded that “the weight of evidence is inconclusive regarding a possible causal relationship between acetaminophen use and neurobehavioral disorders in the offspring.”
The Autism Science Foundation said in a statement Friday that “Any association between acetaminophen and autism is based on limited, conflicting, and inconsistent science and is premature given the current science. … The Autism Science Foundation strongly supports research into autism’s causes. More research needs to be done before alarming families or suggesting steps that may not actually reduce risk.”
HHS Secretary Robert F. Kennedy Jr. has previously promoted debunked theories linking vaccines to autism, and he pledged in April that his agency would have answers this month on the causes of autism. Thousands of researchers from top universities and institutions have applied for federal funding for autism research that Kennedy announced in April, and the US National Institutes of Health is expected this month to announce up to 25 awardees for the $50 million effort.
“We’re finding … certain interventions now that are clearly, almost certainly causing autism, and we’re going to be able to address those in September,” Kennedy said in a Cabinet meeting last month, to which President Donald Trump responded, “There has to be something artificial causing this, meaning, a drug or something.”
Dr. Peter Hotez, a pediatrician who co-directs the Center for Vaccine Development at Texas Children’s Hospital, said it would be irresponsible for Kennedy to cast any one or two things as a “smoking gun” cause of autism.
“That’s not how it works,” said Hotez, who has a daughter with autism and has written a book about the condition.
“We have autism genes, and it’s really important to look at some of the environmental toxins out there that are interacting with autism genes. And it may be possible to compile a list. … But I think it would be reckless to hone in just on those two, at least in terms of the publicly available data,” he said.
Shares of Kenvue fell about 10% midday after the Wall Street Journal report came out.
Dr. David Healy says
Does Tylenol In Pregnancy Cause Autism? Here’s What You Need To Know.
Forbes By Adaira Landry, MD MEd, Sep 06, 2025,
Health and Human Services Secretary Robert F. Kennedy Jr. is expected to release a report on the causes of autism, with particular attention to acetaminophen, the active ingredient in Tylenol, and its use during pregnancy.
In anticipation of this report, it is important for the public to understand physicians’ interpretation of current research and their clinical recommendations.
Does any current research prove acetaminophen causes autism?
It’s crucial to recognize that causation differs from association, correlation or link, terms often used in headlines that may create confusion. Association, correlation, or link means that two events happen together but may not be related. Causation means one event directly causes another. At this time, no studies show acetaminophen causes autism.
Dr. Franziska Haydanek, board certified ob/gyn speaks about Tylenol and pregnancy… \
“There are studies that have linked the use of acetaminophen in pregnancy with neurodevelopmental disorders, although there are conflicting studies about this association,” says board certified obstetrician-gynecologist, Dr. Franziska Haydanek.
A 2024 JAMA study did not demonstrate association with acetaminophen and autism for pregnant patients. However, a 2025 study describes an association between Tylenol use and neurodevelopmental disorders (NDDs), like autism, in 27 of the 46 studies they reviewed.
Dr. Shannon Clark, obstetrician-gynecologist and professor at UTMB-Galveston explains that, for the 2024 JAMA study, “when they looked at numerous different pain relievers in pregnancy, all were associated with neurodevelopmental disorders in offspring, but the associations went away in the sibling control analysis. This lends additional evidence t a genetic cause for NDDs.” In sibling-control studies, researchers compare outcomes between siblings in the same family, which helps account for shared genetics and environment. If an association disappears in this study design, it suggests the cause is more likely family-related factors, like genetics, rather than the medication itself.
Why is there conflicting research on this issue?
“The studies that do show an association have serious flaws and limitations as they do not control for confounding variables,” adds Clark. Confounding variables are hidden factors that influence both the exposure and the outcome. For example, if a pregnant woman takes Tylenol for a fever, the fever itself or the infection causing the fever could be the factor affecting autism risk.
“Another important point is even if we all agreed, according to these studies, that Tylenol is associated with autism, the difference in autism rates between those who took Tylenol and those who did not take Tylenol is very, very low. The vast majority of pregnant individuals who took Tylenol in the reported studies did not have children with autism.” says Clark. She reminds her patients that NDDs will remain challenging to attribute with one isolated culprit because they are multifactorial in origin with genetics playing a leading role.
How long have doctors been studying acetaminophen and autism?
Research exploring the relationship between acetaminophen and autism dates back to the early 2000s. “And 20 years later, we still don’t have any data that supports causation. While some of these studies show an association, none have proven that just taking even a singular dose of tylenol increases the rates of autism or ADHD in offspring,” says Haydanek.
Should pregnant women take acetaminophen when indicated?
According to the American College of Obstetricians and Gynecologists, “Acetaminophen remains a safe, trusted option for pain relief during pregnancy. Despite recent unfounded claims, there’s no clear evidence linking prudent use to issues with fetal development.”
Haydanek adds that she continues to recommend acetaminophen use as she does with any medication. “Use it when needed, in the lowest doses that achieve the desired outcome. We continue to recommend non-pharmaceutical treatments first, and if those do not work, Tylenol is one of our first line treatments in pregnancy for pain and for fevers.” She reminds patients that there are documented risks of maternal fevers.
The dosing for pregnant patients is standard: no more than 4,000 mg per day, typically dosed at 650 to 1000 mg every 4-6 hours.
Where do doctors stand with the current data?
“The current data is still not strong enough for me to consider not prescribing Tylenol in my patients where the benefits outweigh the risks. It’s a well tolerated medication, and one of the only ones we can use for pain and or fevers in pregnancy,” says Haydanek.
Clark adds, “as a Maternal-Fetal Medicine specialist, I say with confidence that pregnant individuals should not be afraid to take Tylenol when indicated. I will continue to recommend Tylenol as the first-line treatment for maternal fever and pain, for which it has known benefits. Untreated pain and fever have known adverse effects in pregnancy.”
What is most important to remember about autism?
Research should focus on identifying the true causes of autism rather than highlighting associations that may unnecessarily alarm for pregnant patients. Misinterpreted or overstated reports or research can undermine trust between patients and clinicians.
Efforts should also prioritize public education, reducing stigma, and strengthening support for families and schools caring for individuals with autism.
Dr. David Healy says
Debate Flares Over an Unproven Link Between Tylenol and Autism
Studies over the last decade of acetaminophen use in pregnancy — including a recent scientific review — have yielded mixed results but have not found a causal connection.
By Azeen Ghorayshi Sept. 5, 2025 New York Times
For more than a decade, scientists have asked whether acetaminophen — the active ingredient in the painkiller Tylenol — could affect fetal brain development, causing problems in children like autism and A.D.H.D. Some studies have suggested that there is a link; others have found none.
Now the latest study, a scientific review by researchers at Harvard’s T.H. Chan School of Public Health and the Icahn School of Medicine at Mount Sinai, has been swept into a larger, politically fraught debate about the causes of autism, spurred in part by the views of Robert F. Kennedy Jr., the Health and Human Services secretary.
There has been speculation that Mr. Kennedy may cite Tylenol use during pregnancy, among other environmental factors, as a potential cause of autism in an upcoming report.
The review that began the latest round of controversy, which examined 46 existing studies, eight of them looking specifically at autism, found there was evidence for a connection between acetaminophen use during pregnancy and neurodevelopmental disorders.
But the researchers who conducted the review cautioned that their conclusion did not mean acetaminophen caused autism, which mainstream scientists overwhelmingly agree is a result of a complex mix of genetic and environmental factors.
And the findings, other experts said, would not alter the advice doctors routinely give pregnant patients about acetaminophen use.
The conclusion of the review “doesn’t change a thing,” said Dr. Nathaniel DeNicola, an OB-GYN who advises the American College of Obstetricians and Gynecologists on environmental issues.
“The conclusion of the paper is that Tylenol should be used judiciously in the lowest dose, least frequent interval,” he said, “which is exactly the current standard of care for Tylenol and for so many medications, and really so many things we may encounter in pregnancy counseling.”
Researchers cannot conduct randomized controlled trials on pregnant women to definitively answer whether the drug causes problems in the developing fetus, because it would be unethical. The studies they reviewed were observational, analyzing data on the women’s pregnancies and then looking at how their children did over time.
Still, the findings circulated widely on social media this week, igniting alarm among parents and autism activists.
The right-wing provocateur Laura Loomer urged “everyone who has ever taken Tylenol or knows someone with autism” to take note, and suggested the common pain reliever could be a culprit behind the rising prevalence of autism diagnoses among children in the United States.
Since he has been in office, Mr. Kennedy has repeatedly said that he thinks genetics play a minimal role in autism, an assertion that autism researchers have vehemently disputed. Instead, he has argued that vaccines and other environmental factors are driving the increased incidence of the disorder in children.
The new report on acetaminophen, published in the journal Environmental Health, came out two weeks before Mr. Kennedy announced at a cabinet meeting that later this month he would be revealing new research findings on “certain interventions” that are “almost certainly causing autism.”
On X, Ms. Loomer speculated that the announcement might include findings about acetaminophen. Children’s Health Defense, the anti-vaccine advocacy group founded by Mr. Kennedy, has raised questions about acetaminophen and neurological problems in children.
But multiple health authorities that have examined the question of acetaminophen use — including the Food and Drug Administration, the European Medicines Agency and the Society for Maternal-Fetal Medicine — have said that the findings are inconclusive, meaning that there is no established risk.
In December 2023, a federal judge ruled against plaintiffs in a class-action lawsuit against Johnson & Johnson and other manufacturers of acetaminophen, citing a lack of scientific evidence for the claim that use of the drug during pregnancy caused autism and A.D.H.D. One author of the new report was an expert witness for the plaintiffs in the case.
Tylenol is the most widely used drug in pregnancy, and given that pregnancy is a crucial window for infant brain development, it continues to be important for researchers to investigate the drug’s potential impacts.
In a statement, Kenvue, the parent company of Tylenol’s manufacturer, said: “Nothing is more important to us than the health and safety of the people who use our products. We have continuously evaluated the science and continue to believe there is no causal link between acetaminophen use during pregnancy and autism.”
The company added, “Acetaminophen is one of the most studied medications in history.” Shares of Kenvue dropped precipitously on Friday after a news report that Mr. Kennedy would link the pain reliever to autism in the forthcoming announcement.
The new study did not provide any new data on the question of what happens when pregnant women take acetaminophen. Instead, it weighed the risk of bias in the existing studies and tried to synthesize the results.
More than half of the studies included in the review found that women who took acetaminophen while pregnant were at higher risk for having children with autism, A.D.H.D. or other neurodevelopmental disorders.
But the study’s authors cautioned that the finding did not mean that acetaminophen was causing autism: The women who took acetaminophen during pregnancy may also have differed in important ways from the women who did not.
“We cannot answer the question about causation — that is very important to clarify,” said Dr. Diddier Prada, an epidemiologist at Mt. Sinai who conducted the study.
He offered an analogy. “Ice cream sales go up in the summer and also violent crime increases during summer — these are associated, but it doesn’t mean that the ice cream is causing violent crime,” he said. “Both increase because of the hot weather.”
The right-wing provocateur Laura Loomer urged “everyone who has ever taken Tylenol or knows someone with autism” to take note.Credit…Greg Kahn for The New York Times
In the same way, women typically take acetaminophen because of health issues during their pregnancies, including infections and fevers, and those problems might increase the risk of neurodevelopmental problems. While many of the studies tried to control for such factors, it is unclear what other variables might not have been accounted for.
One major study published last year tried to take an even deeper look at what hidden factors may be driving the link. The researchers in the study looked at electronic medical records from nearly 2.5 million children in Sweden, finding a small positive association between women who used acetaminophen and the incidence of autism, A.D.H.D. and intellectual disability.
The team did a subsequent analysis to control for the mother’s genetics or pre-existing health issues. Comparing siblings who were exposed to acetaminophen during the mother’s pregnancy to those who were not, the researchers found no difference in the incidence of neurodevelopmental problems.
“Especially in the context of highly heritable developmental conditions like autism and A.D.H.D., genetics is the big unobserved elephant in the room,” said Brian Lee, associate professor of epidemiology at Drexel University and lead investigator of the study.
One smaller study out of Norway also used sibling-matched controls but found differing results based on how long the women recalled having taken acetaminophen during their pregnancies.
Mothers who took the pain reliever for more than 28 days for one of their pregnancies saw a twofold increase in the risk that their baby would have A.D.H.D. But mothers who took the pain reliever for one to seven days during pregnancy actually saw a lowered risk of such problems in their babies compared with siblings who were not exposed to acetaminophen at all.
The researchers said this showed that taking Tylenol for short-term use was better for the baby than, for example, leaving a fever untreated. “It’s protective,” said Eivind Ystrom, a senior researcher at the Norwegian Institute of Public Health and an author of the study. But, he added, “Don’t take it 28 days or more.”
All of the researchers agreed that what was needed to better understand the issue was higher quality research that included robust data on genetics, the dosages and the frequency with which acetaminophen was taken, as well as information on how frequently the pain reliever was administered to infants after they were born.
But researchers also said studies needed to take into account the many factors that contribute to autism.
“To simplify it and boil it down to, ‘It’s just acetaminophen’ is disingenuous and misleading,” said Alycia Halladay, chief science officer at the Autism Science Foundation.
“We know that autism is incredibly complex: It’s the result of genetics and environmental factors that affect the way people respond to the world,” she said. “I think we need to move away from studies that simplify it down to one exposure without any other considerations.”
Dr. David Healy says
Some suggest Tylenol is linked to autism. Here’s what to know.
MAHA activists have been pushing for more investigation into use of the common pain killer during pregnancy.
Washington Post Sept 5, By Ariana Eunjung Cha, Caitlin Gilbert and Lauren Weber
Conservative media and influencers have seized on new research suggesting a connection between Tylenol use during pregnancy and autism, fueling online debate and calls for regulatory action in recent days.
Robert F. Kennedy Jr., secretary of the Department of Health and Human Services, has made autism a key focus of his “Make American Healthy Again” plan, and there has been speculation that his agency would emphasize the link in a highly anticipated report that is expected this month about efforts to uncover causes of autism. Public health experts have feared that Kennedy, an anti-vaccine activist, would also link autism to vaccines, a false claim that he has made repeatedly.
Shares of Kenvue, which makes Tylenol, fell 10 percent in late afternoon trading Friday following a report in the Wall Street Journal that HHS plans to mention the possibility that use of the pain reliever during pregnancy may be linked to the developmental disorder in offspring. An HHS spokeswoman declined to comment except to say that the department is “using gold-standard science to get to the bottom of America’s unprecedented rise in autism rates.”
About one in 36 children have an autism diagnosis, according to data from the Centers for Disease Control and Prevention — compared with one in 150 children in 2000. The reasons behind this sharp increase remain widely debated. Increased awareness and testing almost certainly play a role, but many researchers believe there are additional factors — likely something in our environment or lifestyles — at play in addition to the more than 100 genes that have been linked to the condition. Researchers have not found a link between vaccines and autism in dozens of studies across the globe.
Kenvue said leading medical groups have agreed that acetaminophen is safe to use during pregnancy. “We have continuously evaluated the science and continue to believe there is no causal link between acetaminophen use during pregnancy and autism,” the company said.
Proponents of Kennedy’s position have been actively pushing for more investigation into the common pain killer.
“What we might hear is something about the interaction of Tylenol in the very young together with things that are pro inflammatory, like, say, for example, multiple vaccination. That may be part of the issue associated with autism,” said Robert Malone this week on One America News to host and former republican congressman Matt Gaetz.
Malone, a controversial scientist and Kennedy ally, was named this summer to serve on a key vaccine panel that has promised to examine the childhood vaccine schedule, a longtime goal of Kennedy’s. Malone told The Washington Post that he had not discussed the issue with Kennedy, saying “That’s speculation on my part. I’m not part of any team that is data mining, but that’s what I’m hearing.”
It is unclear whether the September report will mention vaccines.
The recent interest in acetaminophen — the active ingredient in Tylenol — was ignited by a National Institutes of Health-funded study published Aug. 14 in BMC Environmental Health.
The new study, led by Icahn School of Medicine at Mount Sinai researcher Diddier Prada and colleagues at Harvard’s T.H. Chan School of Public Health, involved a rigorous review of 46 previously published epidemiological studies. Of these, 27 reported links between use of the medication by pregnant women and an increased risk of autism or ADHD in their children, 9 showed no link, and 4 indicated protective effects — with the higher quality studies more likely to show a connection.
Prada stressed that the findings do not prove a causal link.
“We show that acetaminophen is associated with a higher risk, but not causing it. Those are very different things,” he said in an interview.
He noted that further research is needed to determine whether the risk is due to the medication itself or to underlying maternal conditions — such as inflammation from fever or infection — that might prompt its use. “This is still an area under investigation,” Prada said.
David Kriebel, professor emeritus of public health at the University of Massachusetts at Lowell, said that although the evidence is “far from conclusive,” it is strong enough to warrant awareness. He said pregnant women may want to limit their use of acetaminophen and consult with their health care providers.
“There is a growing body of evidence suggesting we should be concerned about this possibility,” Kriebel said.
Both Kriebel and Zeyan Liew, an associate professor of epidemiology at the Yale School of Public Health, pointed to growing evidence from lab and animal studies suggesting that acetaminophen may negatively affect fetal development.
Liew said research suggests the possibility that high doses of the drug could interfere with the body’s hormone system or trigger oxidative stress — a condition where harmful substances build up and begin to damage cells.
“These are all unwanted biological effects that we don’t want happening during brain development,” Liew said.
He added that one of the key takeaways from Prada’s study is the need for greater research on how medications, diet, chemicals, and other nongenetic factors influence neurodevelopmental conditions in children.
“Tylenol came into the picture because its use very rapidly increased,” Liew said, “but it’s just one of many thousands of environmental factors we need to study.”
The current guidance on acetaminophen use by the American College of Obstetricians and Gynecologists is similar to that for all medications — which is to consult with their physicians.
But as far back as in 2021, 91 scientists, clinicians and public health professionals from around the world got together to urge stricter guidelines in a statement published in Nature Reviews Endocrinology. They recommended that pregnant women should be cautioned at the beginning of pregnancy to forego acetaminophen unless its use is medically indicated, consult with a physician or pharmacist if they are uncertain and before using on a long-term basis; and use the “lowest effective dose for the shortest possible time.”
In recent weeks, major anti-vaccine, right wing and MAHA influencers have been highlighting a link between Tylenol and autism.
Mentions of “Tylenol” were 15 times more common among MAHA influencers in August compared to April, according to a Post analysis of social media posts and podcasts from over 80 influencers.
Earlier this week on X, far-right political activist Laura Loomer shared a clip from a Fox News show covering the study, writing “If Tylenol and acetaminophen usage by pregnant women is one of the interventions announced this September by @RobertKennedyJr, it could offer a simple step to curb the Autism epidemic in America and around the world, one pill at a time.”
Alex Clark, host of the popular Culture Apothecary podcast, tweeted “NEVER give your baby Tylenol” and discussed the potential harms of the drug in an episode of her show in August.
In a post on Facebook, Moms Across America, which has promoted the false idea that vaccines cause autism, wrote that higher acetaminophen exposure was linked to “3.5x the risk of autism” and encouraged followers to be “embracing the fever as a healing tool.” The post also advertised an herbal supplement with a custom discount code to take instead of Tylenol.
Children’s Health Defense, an anti-vaccine organization that Kennedy founded, has been spreading claims about a link between autism and vaccines for several years. Most recently, it has claimed that Tylenol is dangerous both during pregnancy and to newborns. This week it mischaracterized the results of the new study by writing on X, “They told us Tylenol was harmless. Now Harvard research shows an 80 percent spike in autism risk when used in pregnancy.”
In 2022, Kennedy himself shared an article calling for the end of acetaminophen use in infants and children as the authors claimed it was a potential driver of the “autism epidemic.”
Harriet Vogt says
I’m focusing on Gary Schwitzer’s review – because I haven’t yet read and analysed the APAP propaganda – that’s next.
Although I’m assuming his take is political as was the purpose of the Panel – I think Gary Schwitzer has zeroed in on a communications’ Achilles heel of the format generally.
I felt very slightly discomforted at the time of watching – but couldn’t put my finger on it. Most of my mental space was occupied by feelings of affirmation-evidence to support my existing beliefs, as a pharma heretic, that SSRIs pose serious risks to pregnant women and their babies, like any other toxic substances do. And to attribute every problem a pregnant woman has – particularly those living in deprivation with its associated physical health and social issues – resistance to connecting with services, substance ‘abuse’ (ie trying to the erase the misery) etc. etc. – to ‘untreated depression’ – is as unethical as it is ridiculous.
But imo Gary Schwitzer is right (although I probably don’t understand where ‘he’s coming from’ in the US context)– the meta-communication of the FDA Panel was ‘showtime’ – ‘excited’, ‘next up’, 5-7 minute ‘presentations’, waiting in line to deliver performances, all a bit rushed, however compelling some were, one slide (or none in your case which I thought was the best presentation decision – in 5-7 minutes they need to look at you and listen – not try and read slides as well).
A meta-communication of a scientific process. in my view, would have been round a conference table, scribbling on flip charts, heated arguments about the evidence, running long into the night or nights. Gladiators from both sides of the debate, no death, but plenty of bloodshed for the audience to smell a victor.
The showtime format is obviously what enabled the flimsy – but weighty in terms of volume of coverage – critique – all the classic deflections and defences against the truth of drug risks – industry AI generated boilerplate.
‘alarmingly unbalanced ‘
‘inadequate acknowledgment of harms of untreated ‘depression’ – (the litany that needs taking apart )– ‘ substance use, preterm birth, preeclampsia, limited engagement in medical care and self-care, low birth weight, impaired attachment with their infant, and even suicide’.
‘Robust evidence SSRIs are safe in pregnancy’ ‘MOST do not increase the risk of birth defects’.
I’m guessing the APAP defence will cover much the same ground – just change the drug. But the underlying political drivers still power on.
David T Healy says
I doubt if anyone would disagree – the format was one=sided and male without any real effort or time to come to a consensus.
It should not be about gladiators though. It needs to identify the factors that get in the way of us arriving at a consensus.
Perhaps a new panel to assess what to make of what FDA did and why along with what to make of the media response and why – which if it is to deal with all the issues would need briefing on the relevant elements in the Partnerships in Healthcare post, which stand in the way of consensus
D
Harriet Vogt says
I haven’t got to ‘Partnerships’ – yet. Getting there…
My (audience) feeling of ‘Gladiatorial’ captures the intense emotion around keeping pregnant women and unborn babies safe. Emotion and emotional manipulation are obviously significant obstacles to scientific consensus, especially in the life and death business.
You’re so right – rising above the arena – is the way forward.To a scientific outsider – albeit Kuhn informed (most useful book on my reading list) – rising above the arena doesn’t seem to be the way science operates, though it might work better if it were. it’s more of a knock down fight- until the anomalies (like antidepressant withdrawal) overwhelm those clinging to the wreckage of the past paradigm. And they either claim it was their idea all along – or become dinosaurs.
Harriet Vogt says
Coda
I’ve just done a lightspeed skim of Partnerships – and will give it proper time later.
But it helped me pinpoint why I felt uncomfortable during the FDA Panel.
It wasn’t Science – it was political Marketing.
David T Healy says
Kenvue CEO lobbied RFK Jr. not to cite Tylenol as autism cause, WSJ reports
By Reuters September 12, 2025
Sept 12 (Reuters) – Kenvue’s (KVUE.N), opens new tab interim CEO Kirk Perry met Robert F. Kennedy Jr. to try and dissuade him from listing Tylenol as a potential cause of autism in an upcoming report, the Wall Street Journal said on Friday, citing a person familiar with the matter.
Perry argued at the hastily scheduled meeting this week that there was no clear link between the two, the report said.
WSJ reported on September 5 that the U.S. health secretary planned to announce that the use of Tylenol, a popular over-the-counter pain medication, in pregnant women was potentially linked to autism – contrary to medical guidelines that say it is safe to use.
Kenvue shares fell more than 9% to $18.62 after the report last week. The stock rose marginally on Friday.
The U.S. Department of Health and Human Services did not respond to a Reuters request for comment.
As we would with any regulator who reaches out to us, we engaged in a scientific exchange with the secretary and members of his staff as it relates to the safety of our products, Kenvue said in an emailed response. The company said it continues to believe that taking acetaminophen – the active ingredient in Tylenol – does not cause autism.
Kenvue executives have also argued that there are few safe alternatives to acetaminophen to reduce fevers in pregnant women, according to the WSJ report.
Assertions of a potential link have been the focus of lawsuits brought by parents and autism activists in the United States against retailers.
Ashley Keller, an attorney leading the litigation over claims Tylenol taken during pregnancy can cause autism in offspring, said he would flag a statement from the HHS on the alleged connection to the U.S. appeals court considering whether to revive the lawsuits.
The suits were dismissed after a judge said the scientific evidence the plaintiffs had cited was inadequate.
“I would anticipate if HHS follows through and does the right thing, I am going to alert the (United States Court of Appeals for the) Second Circuit to that,” said Keller. “It’s completely relevant.”
According to researchers, there is no firm evidence of a link between the use of the drug and autism.
David T Healy says
Sept 21 – two articles from the Guardian – Washington Post
Trump officials reportedly set to tie Tylenol to autism risk
Donald Trump’s administration is on Monday expected to tie pregnant women’s use of the popular medicine Tylenol – known as paracetamol elsewhere in the world – to a risk of autism, contrary to medical guidelines, the Washington Post has reported.
Trump officials are also expected to announce an effort to explore how the drug leucovorin could purportedly and potentially treat autism, according to the Post report published Sunday, which cited four sources with knowledge of the plans who spoke on the condition of anonymity because the announcement had not been made.
Medical guidelines say it is safe for pregnant women to take Tylenol, the over-the-counter pain medication whose active ingredient is known as acetaminophen in the US and paracetamol elsewhere in the world.
Trump teased the announcement during the memorial for conservative activist Charlie Kirk on Sunday, telling the crowd “I think we found an answer to autism.” On Saturday, the president said the planned announcement would be “one of the most important things that we will do.”
Earlier in September, the Wall Street Journal reported that Trump’s health secretary Robert F Kennedy Jr planned to announce that use of Tylenol by pregnant women was potentially linked to autism spectrum disorder, which is defined as a neurodevelopmental condition marked by social as well as communication difficulties and behaviors that are repetitive.
As the Post reported, some medical trials involving administering leucovorin to children with autism have shown “what some scientists describe as remarkable improvements in their ability to speak and understand others” – though those trials are considered early.
Kennedy has claimed that the US is in the grip of an “autism epidemic” fuelled by “environmental toxins.”
Decades of research has not yielded firm answers on what contributes to autism, but many scientists believe genetics, potentially in combination with environmental influences, play a role.
Tylenol guidelines: is it safe to use paracetamol during pregnancy?
Donald Trump’s administration is on Monday expected to tie pregnant women’s use of the popular medicine Tylenol – sold generically as acetaminophen in the US and paracetamol elsewhere in the world – to a risk of autism, contrary to medical guidelines, the Washington Post has reported.
The US president teased the announcement during the memorial for conservative activist Charlie Kirk on Sunday, telling the crowd “I think we found an answer to autism.” On Saturday, the president said the planned announcement would be “one of the most important things that we will do”. Trump’s health secretary, Robert F Kennedy Jr, has recently claimed that the US is in the grip of an “autism epidemic” fuelled by “environmental toxins”.
Medical guidelines in multiple countries say it is safe for pregnant women to take the over-the-counter pain medication.
What are the current medical guidelines for pregnant women and paracetamol?
Acetaminophen/paracetamol is the recommended first-line medication for pain and fever during pregnancy in guidelines from the American College of Obstetricians (ACOG) and Gynecologists, Britain’s Royal College of Obstetricians and Gynecologists (RCOG), and other medical organisations.
In the UK, NHS guidelines state: “Paracetamol is the first choice of painkiller if you’re pregnant. It’s commonly taken during pregnancy and does not harm your baby.”
In Australia, paracetamol is listed as safe to use during pregnancy, to help with mild to moderate pain.
However, use of ibuprofen, naproxen and other nonsteroidal anti-inflammatory drugs in the third trimester can lead to birth defects, both ACOG and RCOG warn. Pregnant women should talk to their doctor if they plan to take any of these medications, ACOG advises.
What are the risks of not reducing fever during pregnancy?
Untreated maternal fever and pain during foetal development can increase the risks of birth defects such as heart conditions, abdominal wall defects and neural tube defects in which the brain and spinal cord do not form properly. Untreated pain and fever has also been linked with preterm birth, low birth weight, and miscarriage.
In pregnant women, untreated fever and pain can cause high blood pressure, dehydration, depression and anxiety, and other health problems.
What does the research say on Tylenol use during pregnancy?
There is no firm evidence of a link between the use of acetaminophen or paracetamol and autism. Recent studies have yielded conflicting conclusions on whether its use during pregnancy might create risks for a developing foetus.
A 2024 study of nearly 2.5 million children in Sweden found no causal link between in utero exposure to acetaminophen and neurodevelopmental disorders like autism spectrum disorder or attention deficit hyperactivity disorder.
A 2025 review of 46 earlier studies did suggest a link between prenatal acetaminophen exposure and increased risks of these conditions, but the researchers from the Icahn School of Medicine at Mount Sinai, Harvard University and others said the study does not prove the drug caused the outcomes. They advised that pregnant women should continue to use acetaminophen as needed, at the lowest possible dose and for the shortest possible period.
Large 2025 studies from Europe and Japan have suggested that what might appear to be small associations between prenatal acetaminophen use and neurodevelopmental disorders might actually be due to confounders, that is, other underlying factors – such as environmental conditions, parents’ health and genetics, other medications the mothers may have been taking, and illness.
Why is the subject of acetaminophen in focus now?
Assertions of a potential link have been a focus of hundreds of lawsuits brought by parents and autism activists in the US against retailers, charging they failed to warn consumers that Tylenol and its generic versions could cause ADHD or autism.
In December 2023, a US federal judge barred expert witnesses from testifying after finding they lacked scientific evidence for their claims.
In August 2024, citing that ruling, the judge dismissed all the cases in federal court. A US appeals court is slated to hear arguments next month in an appeal of that ruling, court records show.
Dr. David Healy says
The BBC also wading in – with identical wording
Trump will reportedly link pain reliever Tylenol to autism – but many experts are sceptical
Madeline Halpert
Trump officials are expected to link the use of pain reliever Tylenol in pregnant women to autism, according to US media reports.
At an Oval Office event on Monday, the US president will reportedly advise pregnant women in the US to only take Tylenol, known as paracetamol elsewhere, to relieve high fevers.
At the Charlie Kirk memorial service on Sunday, Trump said he had an “amazing” announcement coming on autism, saying it was “out of control” but they might now have a reason why.
Some studies have shown a link between pregnant women taking Tylenol and autism, but these findings are inconsistent and do not prove the drug causes autism.
Tylenol is a popular brand of pain relief medication sold in the United States, Canada and some other countries. Its active ingredient is acetaminophen, which is called paracetamol outside North America.
Tylenol maker Kenvue has defended the use of the drug in pregnant women.
In a statement to the BBC, it said: “We believe independent, sound science clearly shows that taking acetaminophen does not cause autism. We strongly disagree with any suggestion otherwise and are deeply concerned with the health risk this poses for expecting mothers.”
Acetaminophen is the safest pain reliever option for pregnant women, it added, and without it, women face a dangerous choice between suffering through conditions like fever or use riskier alternatives.
The BBC has contacted the Department of Health and Human Services (HHS) for comment.
In April, the leader of HHS, Robert F Kennedy Jr, pledged “a massive testing and research effort” to determine the cause of autism in five months.
But experts have cautioned that finding the causes of autism – a complex syndrome that has been researched for decades – would not be simple.
The widely held view of researchers is that there is no single cause of autism, which is thought to be the result of a complex mix of genetic and environmental factors.
The American College of Obstetrics and Gynecology said doctors across the country have consistently identified Tylenol as one of the only safe pain relievers for pregnant women.
“Studies that have been conducted in the past, show no clear evidence that proves a direct relationship between the prudent use of acetaminophen during any trimester and fetal developmental issues,” the group has said.
The drug is recommended by other major medical groups as well as other governments around the world.
In August, a review of research led by the dean of Harvard University’s Chan School of Public Health found that children may be more likely to develop autism and other neurodevelopmental disorders when exposed to Tylenol during pregnancy.
The researchers argued some steps should be taken to limit use of the drug but said the pain reliever was still important for treating maternal fever and pain, which can also have negative effects for children.
But another study, published in 2024, found no relationship between exposure to Tylenol and autism.
“There is no robust evidence or convincing studies to suggest there is any causal relationship,” said Monique Botha, a professor in social and developmental psychology at Durham University.
Dr Botha added that pain relief for pregnant women was “woefully lacking”, with Tylenol being one of the only safe options for the population.
Autism diagnoses have increased sharply since 2000, and by 2020 the rate among 8-year-olds reached 2.77%, according to the US Centers for Disease Control and Prevention (CDC).
Scientists attribute at least part of the rise to increased awareness of autism and an expanding definition of the disorder. Researchers have also been investigating environmental factors.
In the past, Kennedy has offered debunked theories about the rising rates of autism, blaming vaccines despite a lack of evidence.
Major medical groups say it is safe for pregnant women to take Tylenol, also known as Paracetamol
Dr. David Healy says
Trump Issues Warning Based on Unproven Link Between Tylenol and Autism
By Azeen Ghorayshi Sept. 22, 2025
President Trump and top federal health officials on Monday launched a broad offensive against the mainstream understanding of autism, claiming without new evidence that acetaminophen — the active ingredient in the common pain reliever Tylenol — was a cause of the disorder.
The officials, including Health Secretary Robert F. Kennedy Jr. and the commissioner of the Food and Drug Administration, Dr. Marty Makary, also endorsed a B-vitamin-based drug, leucovorin, to treat autism. It has only been studied in dozens of research participants.
And they announced new research into the root causes of autism, committing millions of federal dollars to study environmental factors, including a long-debunked theory that blames vaccines.
Together, the announcements marked a new step toward reframing autism as a neglected epidemic with environmental causes to which politicized researchers have long been blind. Most scientists believe that the neurological disorder results from a complex interplay of genetic and environmental factors.
The briefing at the White House featured often unsubstantiated medical advice from Mr. Trump, reminiscent of his first term, when he encouraged Americans to try unproven treatments for Covid.
The president on Monday repeatedly issued strong warnings that flew in the face of the recommendations of leading medical groups: “Don’t take Tylenol. Don’t take it. Fight like hell not to take it.” He urged pregnant women to “tough it out” when in pain, except in rare instances, such as a dangerously high fever.
Scientists have conducted research on a potential connection between acetaminophen and autism for years, but the studies have so far yielded inconclusive results. Mainstream medical groups quickly defended acetaminophen as a safe treatment for fever in pregnant women, although not to be used long-term.
What to Know About Painkillers, Vaccines, Genes and Autism Sept. 22, 2025
Mr. Kennedy noted that autism was a “multi-factorial” disease, but then zeroed in on vaccines, which he has long argued are at least partly to blame for the rising incidence of autism in children. He and Mr. Trump both accused health agencies of previous administrations of purposely turning a blind eye to vaccine risks and dismissed research on the genetics of the neurodevelopmental disorder.
Dozens of studies over the last three decades have failed to find any link between vaccines and autism, and the consensus among scientists is that the idea has been debunked.
Mr. Trump mentioned that he and Mr. Kennedy had long discussed the possibility of a vaccine link. He also amplified Mr. Kennedy’s views, saying that the childhood immunization schedule “loads up” children with too many vaccines. The president said, without evidence, that babies are being given as many as 80 different shots.
“It’s too much liquid, too many different things are going into that baby at too big a number,” Mr. Trump said.
The Food and Drug Administration was far more circumspect, issuing a letter to doctors on Monday that noted, accurately, that “a causal relationship has not been established” between acetaminophen and autism. It stated that the matter is “an ongoing area of scientific debate.”
Asked about the letter, outside experts said it did not change standard medical practice, which already advises minimizing the use of medications, including acetaminophen, during pregnancy.
“Doctors have always approached medications in pregnancy by using it only when indicated, lowest dose, for the shortest duration,” said Dr. Nathaniel DeNicola, an adviser to the American College of Obstetricians and Gynecologists on environmental issues.
“That applies to Tylenol tomorrow the same as it does today, the same as it did yesterday. That is the standard of care: to only use medications when indicated during pregnancy and judiciously,” Dr. DeNicola said.
He pointed out that while the F.D.A.’s letter to physicians indicated that acetaminophen only be used to treat low grade fevers, it is not clear how they defined what a low-grade fever is.
Doctors recommend treating fevers during pregnancy, defined as anything above 100.4 degrees Fahrenheit, because of the risks for both the mother and the fetus, including the risk of neurodevelopmental issues. Acetaminophen is considered one of the few safe options to treat pain or fever during pregnancy.
Because of its widespread use, concerns about acetaminophen and developmental problems in children have been longstanding. Yet scientists overwhelmingly agree that autism results from a complex mix of genetic and environmental factors, and that the rising rates of autism diagnoses cannot be ascribed to just one factor.
In the announcement, health officials repeatedly referred to a recent scientific review by epidemiologists at Harvard T.H. Chan School of Public Health and the Icahn School of Medicine at Mount Sinai.
That article, which reviewed existing scientific studies and did not conduct its own analysis of birth outcomes, concluded that there was evidence of a link between acetaminophen use during pregnancy and neurodevelopmental disorders like attention deficit hyperactivity disorder and autism.
Dr. Makary said at the news conference that Dr. Andrea Baccarelli, the dean of Harvard’s public health school and a co-author of the review, had said it showed there was a causal relationship between the pain reliever and autism.
In a statement on Monday night, Dr. Baccarelli said that more research was needed to determine whether there was a causal link. “But based on existing evidence, I believe that caution about acetaminophen use during pregnancy — especially heavy or prolonged use — is warranted,” he said.
Other authors of the review cautioned that the findings did not mean that there was a cause and effect relationship between the pain reliever and autism.
“We cannot answer the question about causation — that is very important to clarify,” Dr. Diddier Prada, an epidemiologist at Mt. Sinai and the first author on the study, told The New York Times this month.
Studies that have examined the possible risk posed to fetal brain development have been mixed. The review evaluated 46 studies examining a possible link between acetaminophen use during pregnancy and neurodevelopmental issues in childhood, including eight studies that looked specifically at autism. More than half of the studies found a positive association.
Many health agencies — including the Food and Drug Administration and its European equivalent — have evaluated the evidence and concluded that the findings are inconclusive, meaning they found that there is no established risk.
Still, some scientists have recommended that health professionals take a precautionary stance and warn pregnant women about the possibility of a link between acetaminophen and autism.
Most experts believe that it would be unethical to perform pharmaceutical research on pregnant women, which is why the existing research on the effects of acetaminophen were observational, meaning that researchers analyzed data on women’s pregnancies and then looked at how their children do over time.
As a result, researchers cannot account for all of the ways in which women who take Tylenol during their pregnancies may differ from the women who do not.
Many of the studies included in the new review “did not necessarily go to the greatest lengths to account for possible confounders,” Dr. Brian Lee, a professor of epidemiology at Drexel University, said, referring to other factors that might explain a potential link.
“And the biggest elephant in the room here,” he added, “is genetic confounding, because we know autism, A.D.H.D. and other neurodevelopmental disorders are highly heritable.”
In 2024, Dr. Lee was a co-author of a major study that analyzed the health records of 2.5 million children born in Sweden. While the study found a small positive association between women who used acetaminophen and the incidence of autism, A.D.H.D. and intellectual disability, that link disappeared after they did a subsequent analysis comparing siblings born to the same mothers.
The results of the sibling study indicated that the real cause could be maternal genetics, Dr. Lee said, not acetaminophen.
Kenvue, the company that markets Tylenol, rejected the notion of a link between the use of its product during pregnancy and autism. “We believe independent, sound science clearly shows that taking acetaminophen does not cause autism,” Melissa Witt, a spokeswoman for Kenvue, said a statement on Monday evening.
“We strongly disagree with any suggestion otherwise and are deeply concerned with the health risk this poses for expecting mothers and parents.”
The Company Behind Tylenol Tries to Navigate Its Latest Crisis Sept. 22, 2025
Tylenol is the best known among some 600 products containing the active ingredient acetaminophen, an analgesic. Each week, nearly a quarter of U.S. adults use a medicine that contains acetaminophen, according to a trade group for consumer health care products.
Tylenol has been around for 70 years, made for most of that time by Johnson & Johnson. In 2023, Johnson & Johnson spun off Tylenol and other consumer brands to a new company, Kenvue.
On Monday, the F.D.A. also announced that it approved an old, generic drug called leucovorin for symptoms of autism in some children. The medication, approved in a tablet form, has largely been used to treat side effects of chemotherapy.
The agency cited a review of the medical literature, with emphasis on one study that compared about 40 children on the medication with 40 on a placebo that the agency said showed “substantial improvement.” The drug is specifically approved for people with “cerebral folate deficiency,” which is a subset of people with autism.
GSK, which marketed the drug in the 1980s and 1990s, said it would comply with the F.D.A.’s request to update the labeling of the drug to suggest safe use for people with autism.
Pregnant women are already advised to consume folic acid early in pregnancy to promote healthy brain development in the fetus.
Dr. David Healy says
Stat posted the following
Citing possible link to autism, Trump urges limiting use of Tylenol during pregnancy
By O. Rose Broderick Sept. 22, 2025
President Trump announced on Monday that his administration has concluded that some cases of autism may be linked to pregnant women’s use of acetaminophen, the active ingredient in Tylenol, and said the medication should be used sparingly and only if absolutely needed during pregnancy.
Flanked by the nation’s top health officials in the White House’s Roosevelt Room, Trump outlined a dramatic overhaul to health agencies’ approach to autism. The Food and Drug Administration will recommend doctors dramatically scale back acetaminophen use in pregnant women to the lowest effective dose for the shortest necessary duration, and update the medication’s label. The Department of Health and Human Services will also launch a nationwide public information campaign to inform families.
The FDA is taking steps to make available the first drug for children with autistic symptoms tied to folate deficiency in the brain. The medication, leucovorin, has long been used during cancer treatments and has shown some success in improving verbal ability in small numbers of people with autism in small studies. State Medicaid programs will cover leucovorin.
“The meteoric rise in autism is among the most alarming public health developments in history. There’s never been anything like this,” Trump said. He recommended that pregnant women limit use of acetaminophen except in case of an extremely high fever — “if you can’t tough it out.”
Autism researchers say that the scientific literature does not justify the Trump administration’s moving away from Tylenol use during pregnancy and making leucovorin prescriptions available for children with autism. They worry that parents who are desperate to help their kids will turn to an unproven solution — when the history of autism treatments is riddled with purported “cures” that harm more than help.
“I worry that families are going to be putting in a lot of resources and investment into trying to get this treatment [leucovorin] without data showing that it is effective, potentially at the expense of the behavioral interventions and speech therapy and things that we know can be helpful,” Shafali Jeste, a pediatric neurologist who specializes in autism at Children’s Hospital Los Angeles, said prior to the announcement.
What the evidence tells us about Tylenol, leucovorin, and autism
The questions of whether acetaminophen can cause the condition, or leucovorin can treat it, have been studied to a fair degree
By Matthew Herper Sept. 22, 2025
Could Tylenol, one of the most ubiquitous medicines in the U.S., be linked to some cases of autism spectrum disorder when taken during pregnancy? And could leucovorin, a form of folic acid, improve the verbal ability of some people with autism spectrum disorder?
Those are two possibilities that President Trump and Robert F. Kennedy Jr., the secretary of health and human services, seized on Monday in an announcement at the White House. Neither is new; data suggesting that Tylenol use in pregnancy could increase the risk of an infant developing autism and that leucovorin may help some patients have circulated for more than a decade. But in both cases it is exceedingly difficult to tease out verifiable risks and benefits from hypotheses alone.
It’s also important to remember that the exact definition of autism spectrum disorder has varied over time, and that the term is used to describe a wide range of conditions, affecting everyone from those who need round-the-clock care to successful white-collar professionals. Not everyone necessarily reacts the same way to the same medications.
Most researchers who have looked at the question of whether Tylenol taken during pregnancy is tied to autism do not claim the evidence shows that there is a relationship between the two, and some prominent researchers now think the common painkiller is unlikely to play a role.
But there is substantial disagreement. A review of 46 studies published in the journal Environmental Health last month and co-authored by researchers at Harvard University and the Icahn School of Medicine at Mount Sinai concluded that although the data are mixed, it is worth warning pregnant people about the potential risk of taking Tylenol.
“Appropriate and immediate steps should be taken to advise pregnant women to limit acetaminophen consumption to protect their offspring’s neurodevelopment,” the paper concluded, though multiple autism researchers suggested that the paper’s methodology undercut its ability to make that claim.
One of the authors of that paper, Andrea Baccarelli, dean of the faculty at Harvard T.H. Chan School of Public Health, was an expert witness for a plaintiff in a case involving potential links between the use of acetaminophen, the active ingredient in Tylenol, during pregnancy and neurodevelopmental disorders.
Causation, or just correlation?
Multiple studies using different methodologies show that mothers who take Tylenol during pregnancy are more likely to give birth to children who are later diagnosed with autism spectrum disorder. Researchers have been clever about studying the relationship, looking at everything from mothers’ memory of how often they took acetaminophen to levels of chemicals related to Tylenol in umbilical cord blood.
The relationship is relatively small — one study says 5% increase in risk, though a meta-analysis of other studies put the increase in risk at 20% — and would not explain a substantial increase in autism cases in recent years. (Many, though not all, researchers argue that increase is the result of widened criteria for autism spectrum disorder.) But what researchers debate is whether Tylenol might cause autism, or whether Tylenol is simply more often used by people who experience certain conditions during pregnancy, such as infections or migraines, which might also be linked to autism.
This is a key problem in science. Ice cream consumption increases in the summer, as do sunburns and shark attacks. But ice cream does not cause sunburns or shark attacks — they all just happen more often during the summer.
When it comes to Tylenol and autism, one notable paper, published in JAMA last year, tried to deal with this issue by looking at cases in which a mother took acetaminophen in one pregnancy, but not another. The idea was that if genetic or other environmental factors were leading to an increase in autism risk, both siblings would be exposed to the same risk.
The study used a database of 2.5 million children born in Sweden from 1995 through 2019. Of those children, about 186,000 had been exposed to Tylenol in utero.
“In our opinion, this suggests that associations that we see between acetaminophen use during pregnancy and autism or ADHD are most likely non causal and probably due to familial confounding like genetics,” said Brian Lee, a co-author of the study and a professor of epidemiology at Drexel University.
If a mother has a higher genetic risk for ADHD or autism, Lee said, that person is also likely to have more pregnancy pain, more migraines, and use more pain medications — a finding he says has been replicated across the world from the U.K. to Norway to Japan.
“This isn’t something that’s like, oh, you know, we’re only finding this in one sample,” he said. Instead, a genetic risk for autism and ADHD is leading to an association between acetaminophen and those conditions.
This makes sense because many scientists believe that autism spectrum disorder is the result of genetics, and in most people not of a single genetic mutation but of a combination of genetic changes that, depending on how they interact, can cause any number of cognitive or behavioral issues.
Lee noted that it is certainly possible for a drug that is given during pregnancy to increase the risk of autism spectrum disorder, and that the relationship between one epilepsy medicine, valproate, and autism is so strong that researchers use the medicine to cause autism-like behaviors in rats.
Criticism of the Swedish sibling paper
But not everyone agrees that the sibling paper from JAMA is ironclad, and the review of 46 studies includes this paper.
Ann Bauer, a researcher at the University of Massachusetts, Lowell, and a co-author of the review published in Environmental Health, told STAT in an interview that one major issue with the Swedish analysis is that use of acetaminophen was incredibly low. Usually, half of mothers report using the drug at some point during pregnancy; in this database it was only 7.5%. That leads to a concern that mothers were taking acetaminophen but did not report it.
That, she and her co-authors argue, leads to a problem with sibling studies, which they say can underestimate risks in cases where data are not captured. The authors still favor warning pregnant people about the risk, especially if they do not have a high fever and might be able to avoid using it.
The problem, however, is that recommending pregnant people not use acetaminophen leaves them few other options at a time when other drugs can pose clearer risks to a fetus.
The United Kingdom’s Medication and Healthcare products Regulatory Agency said in a statement Monday that “based on rigorous assessment of the best available scientific evidence” it still recommends acetaminophen, known as paracetamol in the U.K., during pregnancy when used as directed.
“Untreated pain and fever can pose risks to the unborn baby, so it is important to manage these symptoms with the recommended treatment,” the agency said.
Does leucovorin help people with autism?
The case of leucovorin is simpler to explain: There are several studies that indicate the medicine can improve the performance of people with autism on standardized tests used to measure verbal ability. But these studies are quite small.
One study, published in the European Journal of Pediatrics, followed 80 patients between the ages of 2 and 10 who were randomly assigned to receive either leucovorin or a placebo. Neither their families nor their doctors knew who received the treatment. At the end of 24 weeks, the children who received leucovorin scored 1.2 points higher on a 60-point scale used to measure autism severity than the children who did not.
The result was statistically significant, but smaller studies are prone to false positive results. The normal course for researchers before making a recommendation would be to conduct a much larger randomized controlled trial to verify that the treatment is beneficial. Most such trials include hundreds or thousands of patients, and provide the best evidence of efficacy and safety.
For both acetaminophen and leucovorin, another problem exists: Generally, high-quality studies of medicines are done by pushing manufacturers to test them. But even though Tylenol, the leading brand of acetaminophen, is a big seller, both acetaminophen and leucovorin are available as generics, which means companies are less likely to pay for large observational studies or randomized controlled clinical trials.
Dr. David Healy says
BBC news on Tylenol – NYT – STAT – BBC etc all saying almost exactly the same things
Trump urges pregnant women to avoid Tylenol over unproven autism link
Madeline Halpert and Nadine Yousif Sept 23
Doctors in the US will soon be advised not to prescribe the pain reliever Tylenol to pregnant women, US President Donald Trump said, citing a disputed link between the drug and autism.
Trump made the announcement on Monday in the Oval Office alongside Health Secretary Robert F Kennedy Jr.
The US president claimed that taking paracetamol, the main ingredient in Tylenol, also known in the US as acetaminophen, “is no good” and that pregnant women should only take it in cases of extreme fever.
Some studies have shown a link between pregnant women taking Tylenol and autism, but these findings are inconsistent and inconclusive. Tylenol maker Kenvue has defended the use of the drug in pregnant women.
In a statement to the BBC, it said: “We believe independent, sound science clearly shows that taking acetaminophen does not cause autism. We strongly disagree with any suggestion otherwise and are deeply concerned with the health risk this poses for expecting mothers.”
Acetaminophen – Tylenol’s active ingredient – is the safest pain reliever option for pregnant women, it added, and without it, women face a dangerous choice between suffering through conditions like fever or using riskier alternatives.
During the announcement on Monday, Kennedy said the Food and Drug Administration (FDA) will issue a physicians notice about what he described as the potential risk of taking Tylenol during pregnancy.
He said the FDA will also begin the process of initiating a safety label change on the medication and launch a public health campaign to spread awareness.
Kennedy added that the FDA will soon approve Leucovorin, a decades-old drug traditionally used to protect cancer patients against toxicity from chemotherapy, to be used as treatment for children with autism.
FDA Commissioner Marty Makary said the approval will be based on research that he said suggests the drug may help children with autism who are deficient in folate, a form of vitamin B, improve their verbal communication.
What is Leucovorin?
The Autism Science Foundation, a US charity, said low folate levels during early pregnancy have been linked in some studies to an increased risk of autism in children, though the findings are not consistent.
Studies in Norway, the US and Israel found that mothers who took folic acid supplements around conception had children with a 30-70% lower likelihood of autism. But other studies did not find a significant association.
The charity said the suggestion folate may improve some symptoms comes from trials of leucovorin, also known as folinic acid.
Some research has shown that unlike regular folic acid, folinic acid can more easily cross the blood brain barrier and address a deficiency of the vitamin.
Four small, randomised trials, all using different doses and measurements of success, have been carried out. One, from 2016, studied 48 autistic children in the US and found improvements in verbal communication compared with a placebo.
But researchers have cautioned that the science is still in the very early stages, and more work is needed before any firm conclusions can be reached.
Medical experts push back
In April, Kennedy pledged “a massive testing and research effort” to determine the cause of autism in five months.
Trump on Monday called the rise in reported autism cases a “horrible crisis”, and an issue that he has “very strong feelings about”.
But experts have cautioned that finding the causes of autism – a complex syndrome that has been researched for decades – would not be simple.
The widely held view of researchers is that there is no single cause of autism, which is thought to be the result of a complex mix of genetic and environmental factors.
Dr Steven Fleischman, president of the American College of Obstetricians and Gynecologists said in a statement that Monday’s announcement “is not backed by the full body of scientific evidence and dangerously simplifies the many and complex causes of neurologic challenges in children”.
The leading medical professional group said doctors across the country have consistently identified Tylenol as one of the only safe pain relievers for pregnant women.
“Studies that have been conducted in the past, show no clear evidence that proves a direct relationship between the prudent use of acetaminophen during any trimester and fetal developmental issues,” the group has said.
The drug is recommended by other major medical groups as well as other governments around the world.
Major medical groups say it is safe for pregnant women to take Tylenol, also known as Paracetamol
In August, a review of research led by the dean of Harvard University’s Chan School of Public Health found that children may be more likely to develop autism and other neurodevelopmental disorders when exposed to Tylenol during pregnancy.
Researchers argued some steps should be taken to limit use of the drug, but said it was still important for treating maternal fever and pain, which can also have negative effects for children.
But another study, published in 2024, found no relationship between exposure to Tylenol and autism.
It was conducted by looking at a population sample of 2.4 million children born in Sweden between 1995 to 2019. Around 7.5% of them were exposed to acetaminophen during pregnancy.
By comparing autism rates between those exposed versus those who were not, as well as comparing siblings who shared genetics, the study concluded that there was no increased risk of autism, ADHD or intellectual disability that can be definitively linked to acetaminophen.
“There is no robust evidence or convincing studies to suggest there is any causal relationship,” said Monique Botha, a professor in social and developmental psychology at Durham University.
Dr Botha added that pain relief for pregnant women was “woefully lacking”, with Tylenol being one of the only safe options for the population.
Autism diagnoses have increased sharply since 2000, and by 2020 the rate among 8-year-olds reached 2.77%, according to the US Centers for Disease Control and Prevention (CDC).
Scientists attribute at least part of the rise to increased awareness of autism and an expanding definition of the disorder. Researchers have also been investigating environmental factors.
In the past, Kennedy has offered debunked theories about the rising rates of autism, blaming vaccines despite a lack of evidence.
Dr. David Healy says
The Daily Beast has provided the most entertaining coverage
RFK Jr. Bizarrely References Sexual Assault in Bonkers Tylenol Takedown
Daily Beast Julia Ormedo Published Sep. 22 2025 10:55PM EDT
Robert F. Kennedy Jr. took a bizarre swipe at sexual assault survivors while delivering a takedown of Tylenol and casting doubt on vaccines alongside President Donald Trump.
The Health Secretary briefly referenced “believe women,” a slogan popularized by the #MeToo movement, while arguing that some mothers of children with autism believe that vaccines injured their kids.
“Some of our friends like to say we should believe all women, but some of these same people have been silencing and demonizing these mothers for three decades because research on the potential link between autism and vaccines has been actively suppressed in the past,” he said.
Trump, 79, Says There’s No Autism in Cuba and the Amish Sarah Ewall-Wice
Kennedy, a longtime vaccine skeptic whose appointment to the helm of the Health Department stirred uproar, found an ally in Trump in his quest to link vaccines to autism despite all science to the contrary.
Kennedy and Trump used a Monday press conference to warn the public against Tylenol, claiming without providing new evidence that the use of the popular pain reliever during pregnancy “can be associated with a very increased risk of autism.”
“It will take time for an honest look at this topic by scientists, but I want to reassure the people in the autism community that we will be uncompromising and relentless in our search for answers,” Kennedy vowed.
Trump Plays Doctor With Wild Advice on Vaccines for Kids Farrah Tomazin
The Health Secretary’s odd remark appeared to reference not just the #MeToo movement, but a slogan that some have claimed was deliberately formulated to muddle the campaign’s message.
The phrase “believe women” rose in popularity as sexual assault survivors spoke out during producer Harvey Weinstein’s public fall from grace in 2017. The Washington Post columnist Monica Hesse argued in 2020, however, that the phrase was eventually twisted into “believe all women” in an effort to strip the original saying of its nuance and “make it seem as if people whose stories are often dismissed or discounted were being crazy for demanding due respect.”
Kennedy is no stranger to the movement against sexual abusers. During his independent campaign for the presidency, Variety reported allegations made against Kennedy by Eliza Cooney, who was a part-time babysitter for the powerful family in the late 1990s.
Cooney recounted that Kennedy groped her twice and made her put lotion on his back. She was 23 and he was 45 at the time.
The Health Secretary faced allegations of sexual assault from a former babysitter for his family. Kevin Lamarque/REUTERS
Kennedy denied the allegations earlier this year when lawmakers were grilling him at his confirmation hearing, but he apologized to Cooney by text when the story first came out in 2024.
“I have no memory of this incident but I apologize sincerely for anything I ever did that made you feel uncomfortable or anything I did or said that offended you or hurt your feelings,” Kennedy told Cooney in a text obtained by the Post. “I never intended you any harm. If I hurt you, it was inadvertent. I feel badly for doing so.”
Cooney told the newspaper at the time that the apology text felt “disingenuous and arrogant.”
“I’m not sure how somebody has a true apology for something that they don’t admit to recalling. I did not get a sense of remorse,” she said.
Dr. David Healy says
Almost as funny as the Daily Beast is Wes Streeting – the UK Health Secretary – featured in the Guardian urging no-one to pay any heed to what Trump says about health
Wes Streeting rejects Trump claim linking paracetamol and autism
Denis Campbell Health policy editor Tue 23 Sep 2025
Wes Streeting has rejected Donald Trump’s unproven claims of a link between taking paracetamol in pregnancy and autism, urging mothers-to-be to ignore the US president’s remarks.
The health secretary challenged Trump’s statements, which medical experts have stressed are not based on evidence, as part of a drive to reassure mothers-to-be in the UK.
“I trust doctors over President Trump, frankly, on this,” Streeting said on ITV’s Lorraine programme. “I’ve just got to be really clear about this: there is no evidence to link the use of paracetamol by pregnant women to autism in their children. None.
“In fact a major study was done back in 2024 in Sweden, involving 2.4 million children, and it did not uphold those claims. So I would just say to people watching: don’t pay any attention whatsoever to what Donald Trump says about medicine. In fact, don’t even take my word for it as a politician. Listen to British doctors, British scientists, the NHS.
“It’s really important that at a time when you know there is scepticism – and I don’t think scepticism itself, asking questions, is in itself a bad thing, by all means ask questions – but we’ve got to follow medical science.”
Trump claimed there had been a “meteoric rise” in the number of cases of autism, pinpointing paracetamol as a cause and advising women not to take the drug during their pregnancy. The US authorities intend that packets of the drug – known there as Tylenol – will in future carry labels linking it to an alleged higher risk of autism.
UK health agencies and experts are staging a concerted effort to counter what one called Trump’s “political misinformation”.
Prof Sir Andrew Pollard, the outgoing chair of the Joint Committee on Vaccination and Immunisation, which advises ministers, said he was “really worried that this rise of misinformation from many different places, including the government in the United States, does undermine confidence globally”.
Dr Alison Cave, the chief safety officer at the Medicines and Healthcare Products Regulatory Agency (MHRA), the UK drugs regulator, said pregnant women should keep taking paracetamol as pain relief, in line with existing guidance.
“Untreated pain and fever can pose risks to the unborn baby, so it is important to manage these symptoms with the recommended treatment,” Cave added.
Prof Claire Anderson, the president of the Royal Pharmaceutical Society, stressed that “paracetamol has been used safely by millions of people for decades, including during pregnancy, when taken as directed”.
The National Autistic Society voiced its alarm at Trump and his health secretary, Robert F Kennedy Jr, blaming paracetamol for autism in children in the US.
“The incessant misinformation about autism from President Trump and Robert F Kennedy Jr risks undermining decades of research by respected experts in the field,” said Mel Merritt, the charity’s head of policy and campaigns.
“Understandably, autistic people will be dismayed and frightened by this announcement, and we would urge our government and the NHS to stand by autistic people and to condemn this misinformation. To do otherwise risks creating further fear, stigmatisation and harm.”
Medical and scientific experts in the UK condemned Trump’s remarks.
“There is a long history of a cottage industry of false causes and ‘treatments’ offered for autism that prey on desperate people’s hopes and fears,” said Dr Steven Kapp, a senior lecturer in psychology at the University of Portsmouth and member of the Coalition of Autism Scientists. “It is sad that unqualified demagogues continue to disregard science.”
Prof Laurie Tomlinson, a National Institute of Health Research professor at the London School of Hygiene & Tropical Medicine, said: “Alongside my research experience, I am also the mother of two autistic children and I know that this announcement will cause distress and guilt to many parents, who often ask themselves whether they are to blame.
“I urge those parents to focus on the countless number of reputable sources of evidence published to date that do not show a link between paracetamol and autism, and to seek medical advice from their own GP or health practitioner.
“I urge you to not get caught up in a political misinformation agenda that is trying to hunt for an ‘easy’ answer as to how autism develops, and does not serve to help our children.”
Dr. David Healy says
The London Times reported the following
Scientist behind Trump’s Tylenol claims was paid $150K to give evidence against drug maker
The Harvard academic Andrea Baccarelli gave an ‘unreliable’ testimony on the links between autism and paracetamol, and produced research that raises ‘serious concerns about bias’
Samuel Lovett, New York Tuesday September 23 2025, The Times
In 2023 a federal court judge in a Tylenol class action found the testimony given by Dr Andrea Baccarelli, above, served “not to enlighten but to obfuscate”
President Trump’s claim that pregnant women can give babies autism by using Tylenol is partly based on a study by a scientist who was previously paid $150,000 to give expert evidence in a claim against the drug’s manufacturers.
Last month Dr Andrea Baccarelli, a senior public health academic at Harvard University, co-authored a review that linked acetaminophen — the active ingredient used in Tylenol — to autism and warned that pregnant women should “limit” their consumption of the drug.
During a press conference on Monday, Dr Marty Makary, commissioner of the Food and Drug Administration, cited Baccarelli’s study — along with two others — as justification for officially advising pregnant women against taking Tylenol. Makary said Baccarelli’s review “found the overwhelming body of evidence points to an association” and quoted the Harvard academic directly as saying: “We cannot wait any longer.”
US President Donald Trump speaking about autism with Robert F. Kennedy Jr. and Mehmet Oz in the Roosevelt Room of the White House.
Robert F Kennedy Jr, the health secretary, President Trump, and Mehmet Oz, the administrator for Medicare and Medicaid, at the announcement of the supposed risks of Tylenol
But in the summer of 2023 Baccarelli served as an expert witness during a class action lawsuit against Kenvue, the maker of Tylenol. A group of parents filed the suit in 2022 with a New York federal court, alleging their children’s autism and ADHD was a result of prenatal use of acetaminophen, which is called paracetamol outside North America. According to a court deposition in August 2023, Baccarelli said he had made “about $150,000” as an expert witness in the case.
Baccarelli, who is the dean of Harvard’s TH Chan School of Public Health and specialises in how environmental exposures affect human health, did not respond to a request for comment. A Harvard spokesperson said that Baccarelli had disclosed his role as an expert witness against Tylenol in his paper.
The complainants in the case engaged five experts, including Baccarelli, to testify in their case. But in December 2023 their testimonies were dismissed by a federal judge, Denise Cote, who found their views to be “unreliable”.
Of Baccarelli’s testimony, Cote said: “The discussion in his reports is incomplete, unbalanced and at times misleading. In general, Dr Baccarelli downplays those studies that undercut his causation thesis and emphasises those that align with his thesis.”
Cote said all five of the experts who testified in the unsuccessful lawsuit against Kenvue “have not served to enlighten but to obfuscate the weakness of the evidence on which they purport to rely and the contradictions in the research.”
A source familiar with the case added that Baccarelli’s expert testimony was later “repackaged” as the study that he co-published last month. The source shared an independent academic review of Baccarelli’s original research that urged him and his co-authors to “[t]emper language” when inferring that prenatal exposure to acetaminophen causes autism. The report concluded that there was an “association” between the two rather than a causal link.
Baccarelli’s finding that there is an association between acetaminophen and autism has also been criticised by members of the scientific community.
Professor David Mandell, associate director for the Centre for Autism Research at the Children’s Hospital of Philadelphia, said Baccarelli’s methodology did not provide a “rigorous review of evidence”. He added that one of the studies examined by Baccarelli’s paper explored the autism-acetaminophen link without providing any measure of autism symptoms. “The statements in the discussion suggesting that the link is strong, rather than somewhat equivocal, combined with the unorthodox methods, raise serious concerns about bias,” he told The Times.
In a statement shared by the White House on Monday, Baccarelli said he had discussed his scientific findings and the recommendation not to take Tylenol during pregnancy with the health secretary, Robert F Kennedy Jr, and the National Institutes of Health, adding he appreciated “their interest in this study”.
Some studies have shown a link between pregnant women taking Tylenol and autism, but scientists say these findings are inconsistent and inconclusive.
For example, a study last year funded by the US government investigated about 2.5 million Swedish children and found some evidence that acetaminophen use during pregnancy causes autism, ADHD or other intellectual disabilities — but this association disappeared when the scientists compared one sibling who had been exposed with another who had not. The study, which is the largest of its kind, concluded that environmental and other health factors, rather than the drug itself, may be responsible.
Autistic Self Advocacy Network, a US non-profit organisation, said that Baccarelli’s review included several studies that were not as comprehensive or thorough as the Swedish study, and that some of the papers included in his research “had biased weighting systems that include parental recall of Tylenol use over hard data”.
Members of the Coalition for Autism Scientists, a group of more than 250 American researchers, added that studies assessing whether acetaminophen causes autism were “difficult to conduct”.
“It is highly irresponsible and potentially dangerous to claim links between potential exposures and autism when the science is far more nuanced and uncertain,” the coalition said this month.
In response to Monday’s press conference, the coalition said the government’s announcement “alarms us researchers who committed our entire careers to better understanding autism. The data cited do not support the claim that Tylenol causes autism … and only stoke fear and falsely suggest hope when there is no simple answer.”
Autism diagnoses in the US have increased sharply since 2000, according to the US Centers for Disease Control and Prevention. Scientists partly attributed this rise to an increased awareness of autism and an expanding definition of the disorder. Researchers have also been investigating environmental factors.
Dr. David Healy says
Dr Baccarelli has followed this article up with a public statement
Posted at 10:45h in Author Interviews, Autism, OBGYNE, Pain Research, Pediatrics by Marie Benz MD FAAD
Statement from Andrea Baccarelli, MD, PhD Dean of the Faculty, Professor of Environmental Health, Harvard T.H. Chan School of Public Health
Colleagues and I recently conducted a rigorous review, funded by a grant from the National Institutes of Health (NIH), of the potential risks of acetaminophen use during pregnancy. We reviewed 46 previously published human studies worldwide.
We found evidence of an association between exposure to acetaminophen during pregnancy and increased incidence of neurodevelopmental disorders in children. This association is strongest when acetaminophen is taken for four weeks or longer.
As we noted in our review, animal studies have independently suggested that prenatal exposure to acetaminophen can adversely affect the developing brain. This biological evidence lends support to the possibility of a causal relationship between prenatal acetaminophen exposure and neurodevelopmental disorders, including autism. Further research is needed to confirm the association and determine causality, but based on existing evidence, I believe that caution about acetaminophen use during pregnancy—especially heavy or prolonged use—is warranted.
At the same time, as the only approved medication for pain and fever reduction during pregnancy, acetaminophen remains an important tool for pregnant patients and their physicians. High fever can pose risks to both the mother and the fetus, including neural tube defects and preterm birth.
After assessing the evidence, my colleagues and I recommended a balanced approach based on the precautionary principle: Patients who need fever or pain reduction during pregnancy should take the lowest effective dose of acetaminophen, for the shortest possible duration, after consultation with their physician about their individual risk-benefit calculation.
I discussed our scientific findings and this recommendation from our review article with Health and Human Services Secretary Robert F. Kennedy Jr. and NIH Director Jay Bhattacharya in recent weeks and appreciate their interest in this study.
Dr. David Healy says
Trump and RFK’s Terrible, Horrible, No Good, Very Bad Autism Press Conference
By Joe Nocera, The Free Press September 23, 2025
https://www.thefp.com/p/trump-and-rfks-terrible-horrible-autism-press-conference-health
The autism community has its factions and disputes, but yesterday most of them agreed on one thing: The press conference held Monday by President Donald Trump and Robert F. Kennedy Jr., secretary of Health and Human Services (HHS)—in which they claimed that autism was linked to Tylenol use by pregnant women—was an abomination.
Paul Offit, head of the Vaccine Education Center at Children’s Hospital of Philadelphia and a board member of the Autism Science Foundation, called it “arguably the most irresponsible public health press conference in history.”
Emily Oster, the CEO of ParentData, who has written frequently about childhood autism, said, “If you look at what they announced, it’s difficult to ignore the drumbeat of every single expert, every professional society—every person who knows about autism knows that the idea that Tylenol causes autism is not well-supported by the data. I mean, they’re really out on the fringe here.”
Holden Thorp, editor in chief of Science magazine—who is himself on the lower end of the autism spectrum—told me that the comments made by the president and the HHS secretary were “misinformed and destructive.”
And Laurie Cameron, the co-founder and executive director of The Extended Family, which provides support services for autistic adults—and who has a profoundly autistic 34-year-old son—said that the press conference “made me so sad. They kept saying how hard it was to watch autistic kids when they get frustrated. It broke my heart to hear that because these are beautiful human beings.”
Over the years, Trump and his officials have said many irresponsible things during press conferences. (Remember when the president recommended in 2020 that people should inject a disinfectant to cure Covid?) So what was it about these remarks in particular that people in the autism community found so offensive?
Let us count the ways.
First, the link between a pregnant woman taking Tylenol and her child developing autism is tenuous at best, but more likely nonexistent. The White House appears to have latched on to a study released last month by a group of scientists led by Andrea Baccarelli, the dean of the faculty at Harvard’s T.H. Chan School of Public Health. It found an “association” between acetaminophen, the active ingredient in Tylenol, and neurodevelopmental disorders, including autism. During the press conference, Trump said that there is a “very increased” risk of autism when pregnant women take Tylenol.
But that’s not remotely what Baccarelli’s study contended. Rather, as he said in a statement to the White House, “there is a possibility of a causal relationship,” and added that more study was needed, according to The Harvard Crimson. What’s more, a far more extensive study in Sweden, published last year in the Journal of the American Medical Association, found “no evidence of increased risk of autism.”
“That paper provides strong evidence that there is no causation with Tylenol,” Thorp told me.
It’s no secret that RFK Jr. has long wanted to prove a link between vaccines and autism. From 2015 to 2023, he ran a group called Children’s Health Defense, which campaigns against childhood vaccinations. As HHS secretary, he fired all 17 members of the CDC’s vaccine advisory committee and replaced many of them with vaccine skeptics.
And in April he set a September deadline to identify the cause of autism, something scientists, of course, have been trying to do for decades. “When they couldn’t find any new evidence on vaccines, they fished around and found this Tylenol paper,” Thorp added. “I guess they said, ‘Let’s go with it.’ ”
The link between a pregnant woman taking Tylenol and her child developing autism is tenuous at best, but more likely nonexistent.
An autism researcher, who asked that her name not be used because she has dealings with the administration, said that the press conference “should never have taken place. They had a bee in their bonnet about making a big autism announcement in September, and September was almost over. They had to keep the train rolling.”
The second problem with the press conference was the clear implication, especially as it was framed by Trump and RFK Jr., that if a pregnant woman takes Tylenol and her baby winds up with autism, it’s her fault. “Don’t take Tylenol,” the president said. “Don’t take it. Fight like hell not to take it.” Women who are in the kind of pain that Tylenol relieves need to “tough it out.”
This is a huge and lamentable step backward. Leo Kanner, the first doctor to identify autism in children in 1943, believed that it was caused by emotionally frigid mothers who were distant from their children. He coined the repulsive phrase “refrigerator mothers” to describe them. Mothers who had autistic children were often tormented with guilt. “It took decades of research to discredit that theory and now they’re telling moms if they take Tylenol they are doing something wrong?” said Thorp. “They are undoing so much progress.”
Third, the recommendation that pregnant women not take Tylenol could actually cause quite a bit of harm if doctors were to adhere to it. Why? Because acetaminophen is the only drug women can safely take for pain relief during pregnancy. As Baccarelli noted in his statement to the Trump administration: “As the only approved medication for pain and fever reduction during pregnancy, acetaminophen remains an important tool for pregnant patients and their physicians.” Besides, high fevers, if untreated, have the potential to cause damage to a fetus. The good news—if you can call it that—is that most doctors are likely to ignore the FDA’s recommendation.
An autism researcher, who asked that her name not be used because she has dealings with the administration, said that the press conference “should never have taken place.”
Fourth: During the press conference, Trump said that autism sufferers should use a drug called leucovorin, which has long been used as a treatment for colon cancer. On Monday, it was approved by the Food and Drug Administration for autism as well—without any rigorous studies having been conducted. What the president failed to add is that its potential efficacy is extremely limited.
“In some small-scale studies, it has shown some promise in improving some speech-related issues,” Oster told me. “I think many experts would say it is an interesting thing to explore, but not something where we have large-scale, convincing evidence yet. I think people might have come away from the press conference thinking that this drug is a cure for autism. And it’s not.”
Fifth: It was discouraging to see officials who should know better, like Dr. Jay Bhattacharya, the head of the National Institutes of Health, and Dr. Martin Makary, the FDA commissioner, standing straight-faced behind Trump as he said things like “There’s a rumor, I don’t know if it’s so or not, that Cuba, they don’t have Tylenol because they don’t have the money for Tylenol. And they have virtually no autism.” Sadly, when called up, both men joined the chorus. Makary said, among other things, that giving pregnant women Tylenol to subdue fevers amounted to a “perfunctory, reactionary, mindless practice of medicine.”
If there was any good news at all, it was that the NIH is planning to spend an additional $50 million to “turbocharge autism research,” with a focus on “root causes and therapies.” There is no doubt the research is needed. But if the money is spent trying to prove the Tylenol theory to make the president happy, it will be money wasted. Indeed, the strongest evidence, according to Thorp, is that autism is the result of inherited genetic mutations as well as environmental factors. Bhattacharya knows that too, and if he uses this awful press conference as cover to fund serious research, that could be the silver lining.
One other thing: At one point in the proceedings, Kennedy muttered something about how this is all part of the administration’s effort to restore trust in government. That’s a worthy goal, especially after the government’s response to the pandemic did so much to undermine trust in public health institutions. But I’ve said it before, and I’ll no doubt say it again before this administration is done: If Trump and RFK Jr. are trying to restore faith in public health, they sure have a funny way of going about it.
Dr. David Healy says
Britain’s former Deputy Prime Minister Nick Clegg, formerly of Facebook has said its cringing to see Keir Starmer bend the knee before Donald Trump.
Britains FDA (MHRA) usually bend both knees in front of FDA but on this paracetamol occasion are standing upright (and looking a touch ridiculous)
Paracetamol and pregnancy – what you need to know
DHSC Media Team, 23 September 2025
THE FACTS
• There is no evidence that taking paracetamol during pregnancy causes autism in children.
• A major study conducted in Sweden in 2024, involving 2.4 million children found no evidence that paracetamol causes autism in pregnancy.
• Untreated pain and fever can pose real risks to the unborn baby, so it is crucial to manage these symptoms with the recommended treatment. Paracetamol continues to be the recommended pain relief option for pregnant women when used as directed.
• Patients should not swap to alternatives such as ibuprofen, as non-steroidal anti-inflammatory drugs (NSAIDs) are generally not recommended during pregnancy
Q&A
Is paracetamol safe to use during pregnancy?
Yes. Current evidence supports the safe use of paracetamol during pregnancy when used as directed. This advice has been consistent for many years.
The MHRA regularly reviews the safety of paracetamol during pregnancy to ensure that the benefits to the paint and unborn baby outweigh any risks.
Paracetamol is recommended by NHS guidance as the first-choice painkiller for pregnant women, to be used at the lowest dose and for the shortest duration. If pain does not resolve then patients are advised to seek advice from their healthcare professional.
Should pregnant women stop taking paracetamol?
No. Pregnant women should continue to follow current medical guidance. Paracetamol remains a recommended painkiller during pregnancy when used as directed. Women with concerns should speak to their healthcare professional rather than stopping medication without medical advice.
Will the MHRA review its guidance following the US announcement?
No.
The MHRA carefully monitors new evidence on the safety of medicines and takes action when evidence shows a potential risk to patients.
In the case of paracetamol use in pregnancy, recent studies, including the one published in August, have not established a direct relationship between paracetamol use during pregnancy and an increased risk of autism.
How does the MHRA monitor medicine safety in pregnancy?
The MHRA has comprehensive systems including the Yellow Card Scheme for reporting suspected side effects, analysis of healthcare databases, and review of international evidence. MHRA works closely with healthcare professionals and regularly update guidance when new evidence emerges.
Dr. David Healy says
the Guardian and Barack Obama have also weighed in
Obama says Trump linking paracetamol to autism is ‘violence against the truth’
Lanre Bakare 24 Sep 2025 18.23
Barack Obama has said Donald Trump’s claims linking paracetamol to autism in infants is “violence against the truth” that could harm pregnant women if they were too scared to take pain relief.
Obama, who was being interviewed by David Olusoga at the O2 Arena, told the audience that Trump’s claims about paracetamol – branded as Tylenol in the US – had been “continuously disproved” and posed a danger to public health.
“We have the spectacle of my successor in the Oval Office making broad claims around certain drugs and autism that have been continuously disproved,” he said. “It undermines public health … that can do harm to women.”
On Monday Trump had said: “Taking Tylenol is not good … All pregnant women should talk to their doctors about limiting the use of this medication while pregnant.”
The comments were criticised by the UK health secretary, Wes Streeting, who encouraged women to ignore the president’s comments.
Obama argued there was a “tug of war” between two visions for the future of the US and humanity. On one side the progressive view where change came through democracy, the other driven by populists including Trump wanting a return to an older, more conservative worldview.
Barack Obama who is on a European speaking tour was interviewed by historian David Olusoga at the O2 Arena. Photograph: PR IMAGE
He said: “My successor has not been particularly shy about it. That desire is to go back to a very particular way of thinking about America, where ‘we, the people’, is just some people, not all people. And where there are some pretty clear hierarchies in terms of status and who ranks where.”
Obama was also critical of progressives who he said became “complacent” and “smug” in the 90s and 00s, “posturing that we believe in all these values because they were never tested. Now they’re being tested”.
The former president has generally kept a low profile after leaving office. But he has made increasingly frequent interventions as the political landscape in the US becomes more violent, restive and divided along partisan lines.
In London, Obama did not refer to Trump by name, only as “my successor”.
The evening started with Olusoga welcoming the London mayor, Sadiq Khan, who had been criticised by Trump on Tuesday during his speech at the UN in New York. Khan had responded by saying Trump had “shown he is racist, he is sexist, he is misogynistic and he’s Islamophobic”.
Dr. David Healy says
Britain’s Royal College of Obstetricians and Gynecologists weighs in
The Royal College of Obstetricians and Gynaecologists issues advice for pregnant women and people on the use of paracetamol to manage fever and pain
23 Sept 2025
The Medicines and Healthcare products Regulatory Agency (MHRA), The World Health Organization (WHO) and the European Medicines Agency have all published clear statements on the safety of paracetamol use in pregnancy, stating that there is no confirmed link between taking paracetamol during pregnancy and autism in children.
Paracetamol remains the recommended pain relief option for pregnant women when clinically needed and used as directed.
Professor Ranee Thakar, President of the Royal College of Obstetricians and Gynaecologists, said:
“Managing pain and fever during and after pregnancy is really important for the wellbeing of women and their babies. Pain can impact a woman’s physical and psychological health, while unmanaged fevers can pose risks for both the mother and unborn baby. The MHRA statement is clear that Paracetamol remains the recommended pain relief option for pregnant women when used as directed. It is vital that women have access to accurate, evidence-based information. If you are concerned or have questions about the use of paracetamol, please speak to your pharmacist or maternity team as soon as possible.”
Notes to editors:
• Paracetamol is recommended as the first-choice painkiller for pregnant women, used at the lowest dose and for the shortest duration.
• Women with unresolved pain or fever, or those with concerns about the use of paracetamol, are urged to speak to a pharmacist, GP or midwifery team as soon as possible
• Further information can be viewed at:
• Royal College of Obstetricians and Gynaecologists – Antenatal and Postnatal Analgesia (Scientific Impact Paper No. 59)
• MHRA Media Statement
• MHRA- Drug Safety update
• DHSC- Paracetamol and Pregnancy factsheet
• NHS Guidance – Pregnancy, breastfeeding and fertility while taking paracetamol for adults
• MHRA social media video
Dr. David Healy says
This report contains a link that doesn’t show to a second Daily Caller piece – Pregnant Influencers Seemingly Try to Own Trump with Tylenol – which has an interesting suggestion about Daddy Issues.
Tylenol Maker Privately Admitted Evidence Was Getting ‘Heavy’ For Autism Risk In 2018
Daily Caller Emily Kopp September 26,
The pharmaceutical company behind Tylenol privately acknowledged the likelihood of an association between its drug in pregnancy and neurodevelopmental disorders like autism in children seven years ago, company documents obtained by the Daily Caller News Foundation show.
“The weight of the evidence is starting to feel heavy to me,” said Rachel Weinstein, U.S. director of epidemiology for Janssen, the pharmaceutical arm of Johnson & Johnson, in 2018. Johnson & Johnson marketed Tylenol at the time but in 2023 spun off its consumer products division into a separate company called Kenvue.
Legacy media headlines and vocal public health experts have dismissed the conclusion of President Donald Trump and Health and Human Services (HHS) Secretary Robert F. Kennedy Jr. that Tylenol taken in pregnancy and early infancy has driven rises in autism. But one stakeholder has for years viewed the evidence as credible enough to act upon, at least privately: The makers of Tylenol. (RELATED: Trump Unveils Results Of Autism Study)
The DCNF obtained the company documents from the law firm Keller Postman LLC, which brought a class action lawsuit against Kenvue in the Federal District Court for the Southern District of New York.
To be sure, much of the highly-cited research on autism spectrum disorder emphasizes genetic rather than environmental drivers. The scientific community continues to debate its causes, with many scientists agreeing that multiple factors may be at play.
The company’s FAQ webpage says that “acetaminophen is an active ingredient in all TYLENOL® products and in more than 600 other over-the-counter (OTC) and prescription medicines.”
A decade before Weinstein’s email, in 2008, Johnson & Johnson began receiving queries from consumers and physicians about a possible link, emails show.
“Not much choice but to consider this a safety signal that needs to be evaluated,” J&J Office of Consumer Medical Safety Lead Andre Mann wrote in 2008 after receiving a letter from a physician with concerns.
Leslie Shur, the head of the division of Johnson & Johnson that monitors the side effects of drugs already on the market, received an alert in 2012 about concerns about acetaminophen and autism from a concerned father, with one employee writing “in case this goes to press.”
Concerns about a link between Tylenol and neurological disorders may have reached the C-suite by 2014, according to another email, which references then-Johnson & Johnson CEO Alex Gorski.
The makers of Tylenol have closely tracked a drumbeat of scientific publications finding an association between taking the blockbuster drug in pregnancy and infancy and autism risk, other company documents show. (RELATED: Pregnant Influencers Seemingly Try To Own Trump With Tylenol)
A 2018 internal presentation the company labeled “privileged and confidential” acknowledges that observational studies show a “somewhat consistent” association between prenatal exposure to Tylenol and neurodevelopmental disorders. Another presentation slide acknowledges that larger meta-analyses — reviews summarizing multiple scientific studies — found an association, but notes weaknesses of these studies like confounding variables and subjectivity in measuring autistic traits.
“Johnson & Johnson divested its consumer health business years ago, and all rights and liabilities associated with the sale of its over-the-counter products, including Tylenol (acetaminophen), are owned by Kenvue,” a Johnson & Johnson spokesman said in a statement.
Shur did not respond to a request for comment. Mann and Gorski could not be reached for comment.
“Nothing is more important to us than the health and safety of the people who use our products,” Kenvue spokesperson Melissa Witt told the DCNF. “We have continuously evaluated the science and continue to believe there is no causal link between acetaminophen use during pregnancy and autism.”
“Acetaminophen is the safest pain reliever option for pregnant women as needed throughout their entire pregnancy,” Witt continued. “Our products are safe and effective when used as directed on the product label. We recommend pregnant women do not take any over-the-counter medication, including acetaminophen, without talking to their doctor first.”
Hearings before the Court of Appeals for the Second Circuit in the class action suit against Kenvue will begin Oct. 9. Judge Denise Cote granted summary judgement for Kenvue in September 2023, after tossing the scientific testimony from experts for Keller Postman, citing the “great public health implications” of pregnant women not having the drug.
Ashley Keller, lead attorney for the families with autistic children, argues the judge overstepped and that women should be alerted to the risk.
“We saw this nonsense with COVID on all sorts of things that turned out to be untrue. They said these lies were noble lies. Well, we shouldn’t sugar coat things for pregnant moms,” he said to the DCNF.
The judge also responded to the internal records showing that the company knew about studies showing an autism risk by saying that “candid internal discussion […] is positive corporate behavior.”
Meanwhile, Kenvue states on the website for Tylenol that “credible, independent scientific data continues to show no proven link between taking acetaminophen and autism.”
“If you are treating your little one with acetaminophen, please know that there is no credible science that shows taking acetaminophen causes autism,” the site also reads.
Internal emails sharply contrast with that public statement.
Emails show employees of Johnson & Johnson discussing a 2018 literature review concluding that pregnant women should be cautioned against indiscriminate use of Tylenol as well as a 2016 study that concluded that prenatal exposure to acetaminophen was associated with autism “with hyperkinetic features,” or abnormal involuntary movement, though not with autism without those symptoms.
Weinstein, the company epidemiologist, wrote to one of the authors lauding the “substantial strengths of the study design,” the “strength and robustness of the association,” and the study’s ability “to control for possible confounding by indication,” that “lend support to the findings.” Weinstein joined Kenvue from Johnson & Johnson but has since retired, her LinkedIn shows. She could not be reached for comment.
In 2018, Weinstein and other top scientists within the company considered funding follow-on studies about the drug’s autism risk but eventually opted against “sticking their necks out.” Weinstein mentioned that they could end up confirming the findings. The company noted in a 2018 presentation that recommending against Tylenol in pregnancy would leave women with few options.
Tylenol has few competitors among pregnant women, with ibuprofen and aspirin discouraged in late pregnancy due to potential complications.
The company also conducted research it described as “social listening” by tracking Google searches and social media posts seeking evidence about Tylenol and autism from January 2020 through October 2023. The company initiated the social media trends research after the 2021 publication of a call to action on Tylenol in Nature Reviews Endocrinology by 13 U.S. and European experts “in light of the serious consequences of inaction.”
That same year, the company ran a Mother’s Day ad featuring pregnant women and women with small infants and the Tylenol brand. Nevertheless, the company found “a substantial increase in negative sentiment on this topic in the news and social media,” the social listening report states.
Acknowledging a plausible risk to babies could have tarnished the Tylenol brand, employees admitted internally. In a 2023 internal review dubbed Project Cocoon, company executives acknowledged that the question “touches every aspect of the brand.”
The company had in 2015 launched Tylenol as a “megabrand,” marketing it as vital for all stages of life, including in pregnancy and early infancy, internal marketing plans show.
Just two years before, a 2013 ProPublica investigation had uncovered the company had also been slow to update its label with information about the risk of overdose. Tylenol caused 1,500 overdose deaths from 2001 through 2010, more than every other over-the-counter painkiller combined, according to the report. That same year, Tylenol added a message to the bottle caps of its extra strength formulation: “CONTAINS ACETAMINOPHEN” and “ALWAYS READ THE LABEL.”
The renewed push to tie the Tylenol brand to themes of family and safety followed.
“Come back,” one marketing slide reads, showing a picture of a mother and baby.
The class action suit centers on whether the company was negligent in ignoring a credible connection. According to William Parker, CEO of WPLab, Inc. and a neuroscientist formerly associated with Duke University, the hypothesis was first presented in 2008, with strong animal model studies showing its toxicity by 2014.
At the same time, some studies made what Parker describes as a statistical mistake: controlling for factors like genetic predisposition that exacerbate the effects of Tylenol as confounding variables.
“It’s like saying kids playing with matches are perfectly safe when there’s not anything flammable around,” Parker said.
However by 2017, a peer reviewed paper coauthored by Parker connected the genetic and environmental variables with acetaminophen, bringing the probable association between acetaminophen and autism into clearer focus, he said.