Appeals Court Revives Private Lawsuits Linking Tylenol to Autism

A federal appeals court on July 13 revived more than 500 private lawsuits against Tylenol maker Kenvue over the painkiller’s alleged link to autism.

The 2nd U.S. Circuit Court of Appeals in Manhattan said a district court judge improperly excluded testimony from expert witnesses offered by parents and guardians who tied Tylenol use during pregnancy to autism and attention deficit hyperactivity disorder in children.

There is no firm scientific evidence of such a link. The issue drew greater attention after President Donald Trump and top U.S. health officials in September suggested a link to autism.

Kenvue did not immediately respond to a request for comment. Its shares traded down 10 cents at $19.38 in morning trading.

Monday’s decision followed Kenvue’s agreement last November to be acquired by Kleenex tissue maker Kimberly-Clark for more than $40 billion.

Doctors and medical societies consider acetaminophen, the active ingredient in Tylenol, the preferred means to treat pain and fever during pregnancy, and Kenvue has long maintained that Tylenol is safe.

Kenvue, based in Summit, New Jersey, was spun off in 2023 by Johnson & Johnson, which made Tylenol for more than 60 years and also defended its safety.

The private lawsuits were dismissed in December 2024 by U.S. District Judge Denise Cote in Manhattan, who criticized the methodology of the plaintiffs’ expert witnesses, who included Harvard School of Public Health Dean Andrea Baccarelli.

Experts often play a key role in product liability lawsuits such as the Tylenol cases.