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Makers of Tylenol and the U.S. Food and Drug Administration (FDA) knew for years about the likely association between the drug’s use during pregnancy and neurodevelopmental disorders, including autism, according to documents obtained in lawsuits against Kenvue.
“The weight of evidence is starting to feel heavy to me,” Rachel Weinstein, U.S. director of epidemiology for Johnson & Johnson’s (J&J) pharmaceutical division Janssen, said in an email commenting on several studies showing the link.
Daily Caller News Foundation obtained the emails from Keller Postman LLC, the law firm representing plaintiffs in a federal class action lawsuit against Kenvue.
J&J made Tylenol until 2023, when it spun off production to Kenvue, a separate company.
The email revelations follow President Donald Trump’s announcement last week that pregnant women should not take Tylenol, and the FDA’s announcement that it will add warnings to products containing acetaminophen.
The updated product labels will warn that acetaminophen may be associated with a higher risk of neurological conditions, including autism and attention-deficit/hyperactivity disorder (ADHD), in children. The FDA said it will also warn physicians and the public about the risk.
Mainstream media and public health organizations attacked the warnings as unfounded or overblown. Some news organizations quoted scientists — like University of Massachusetts epidemiologist Ann Bauer — who published studies identifying the link between Tylenol and autism and called for warnings, but who are now publicly backpedaling on their concerns.
However, the Daily Caller found that despite confusion in the media and among public health experts, emails show that as early as 2008, officials at J&J were privately concerned about credible evidence of a possible link between autism and acetaminophen. They acknowledged the link in an email and suggested further investigation.
Internal FDA meta-analyses shared with The Defender show that the agency had for years considered adding new warnings about acetaminophen’s side effects for children.
In 2019, FDA scientists conducted a meta-analysis that found urogenital disorders in infants linked to the drug. The scientists also noted links to neurodevelopmental issues. In 2022, the FDA conducted another meta-analysis that found a link to ADHD.
Tylenol makers ‘closely tracked a drumbeat of scientific publications’ showing link to autism
The Daily Caller News Foundation obtained emails spanning more than a decade indicating that company insiders at J&J had been alerted about the possible link between acetaminophen and neurological disorders. The emails showed J&J even considered pursuing further research, but decided against it.
The outlet also obtained a 2012 email by Leslie Shur, head of the division at J&J that monitors side effects, acknowledging another consumer complaint about the issue, and a 2014 email showing that the issue was raised with CEO Alex Gorsky, whose name is misspelled in the email.
According to journalist Emily Kopp, who wrote the Daily Caller story:
“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.”
A Kenvue spokesperson told the Daily Caller that the company believes there is “no causal link between acetaminophen use during pregnancy and autism” and that its products are “safe and effective” when used as directed on the label.
Kopp noted the company’s website also states that “credible, independent scientific data continues to show no proven link between taking acetaminophen and autism,” and that “there is no credible science that shows taking acetaminophen causes autism.”
Yet, she found that internal emails showed employees discussing a 2018 study and a 2016 study that both concluded pregnant women should be cautioned about the possible effects of taking Tylenol while pregnant.
She also found emails indicating that J&J considered funding studies on Tylenol’s possible link to autism, but decided against “sticking their necks out,” worried their studies could confirm the findings.
According to Kopp:
“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.’”
The company wrote a 2023 review, Project Cocoon, which reported on concerns with urinogenital and neurological side effects of the drugs in babies, which executives noted touches “every aspect of the brand,” Kopp wrote.
FDA also concerned with mounting evidence
The FDA also grew concerned with the mounting evidence of a link between acetaminophen and neurodevelopmental disorders, beginning with a publication in JAMA Pediatrics in 2014 and followed by several major publications over the next several years, according to psychiatrist David Healy.
Healy is an expert witness in a case against Kenvue and Safeway, alleging they failed to adequately warn consumers about the risk of autism or ADHD from prenatal exposure to the drug.
Documents from 2019 and 2022, made available through Freedom of Information Act requests associated with the lawsuit and shared with The Defender, show that based on meta-analysis of the published literature, the FDA identified consistent links between acetaminophen and both urogenital and neurodevelopmental risks.
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As early as 2019, FDA study authors recommended that the labels be revised to advise pregnant women to “be careful about casual use of acetaminophen when it is not strongly needed for pain or other purposes.”
The 2022 document, focused largely on neurological outcomes, states that despite study limitations, meta-analyses and other research consistently found links between acetaminophen and ADHD, and as a result, “it may be prudent, as a precautionary measure …” However, the rest of the recommendation is redacted.
Healy said the revelations by Weinstein and others working with J&J are particularly significant because drugmakers have the responsibility to inform consumers when they know a drug may be linked to an adverse event.
“The onus to warn does not arise when there is a clear cause and effect,” Healy said. “It arises when there are grounds to think there might be a problem.”
Related articles in The Defender- Families Behind Hundreds of Tylenol Lawsuits Ask Court to Let Experts Testify
- Exclusive: Hundreds of ‘Tylenol Lawsuits’ Allege Retailers, Manufacturers Knew Acetaminophen During Pregnancy Could Cause Autism, ADHD
- Media Claims ‘No Science’ Linking Tylenol to Autism — But Studies by Major Medical Institutions Raise Red Flags
