(DCNF)—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.

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.

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.

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