Request made to court in Tylenol-autism lawsuits

(Reuters) — Families appealing the dismissal of their lawsuits alleging that Kenvue’s Tylenol or generic versions of the pain-relief medication caused their children’s autism are asking an appeals court to consider President Donald Trump’s new advice that pregnant women avoid the painkiller as it decides whether to revive their lawsuits.

Ashley Keller, an attorney representing the plaintiffs, filed a letter Wednesday alerting the New York-based 2nd U.S. Circuit Court of Appeals to the Trump administration’s stance on the alleged link between Tylenol and autism. In a news conference at the White House on Monday, Trump delivered medical advice to pregnant women, repeatedly telling them not to use acetaminophen, the active ingredient in Tylenol.

A judge last year dismissed hundreds of lawsuits alleging a connection between Tylenol or generic versions of the drug and autism or ADHD diagnoses, saying that the experts the plaintiffs relied on had failed to support their conclusions with scientific evidence.

In Wednesday’s letter, Ms. Keller told the appeals court that a ruling upholding the lower court’s decision to dismiss the cases for lack of scientific evidence would pose “grave separation of powers concerns,” because the Trump administration had turned to one of the same experts in developing its position.

Ms. Keller noted that during Monday’s press conference, U.S. Food and Drug Commissioner Marty Makary, Health Secretary Robert F. Kennedy Jr. and Trump cited the research on Tylenol and autism done by Andrea Baccarelli, currently dean of the faculty at the Harvard T.H. Chan School of Public Health, one of the plaintiffs’ experts.

Jay Lefkowitz, an attorney for Kenvue, in a filing to the appeals court responding to Ms. Keller’s letter, highlighted that a note the FDA sent to physicians in conjunction with Mr. Trump’s press conference said a causal relationship between autism and acetaminophen had not been established, which is what the district court had found. He also noted that Mr. Baccarelli said this week that further research is necessary to confirm an association and determine causality.

“There is thus no conflict between the government’s action and the district court’s opinion, much less a ‘separation of powers’ problem, as Plaintiffs suggest,” Mr. Lefkowitz wrote.

A representative for Mr. Baccarelli said he was not available to comment.

In a statement, a Kenvue spokesperson said the company believes it will continue to be successful in the litigation as the claims lack legal merit and scientific support.

The 2nd Circuit had been slated to hear arguments in the case on October 6, but on Thursday the court pushed the arguments back to November.

Legal experts have said it would be unusual if the appeals court gave the administration’s actions and Mr. Trump’s comments much weight in considering how to move forward with the cases.

“It’s not as if there’s been a new study that has been announced that has a different conclusion,” Elizabeth Chamblee Burch, a professor at the University of Georgia’s School of Law whose research focuses on cases like the Tylenol litigation, said on Tuesday before Ms. Keller filed the letter.

Researchers say there is no firm evidence of a link between the use of Tylenol and autism. A 2024 study of nearly 2.5 million children in Sweden found no causal link between in utero exposure to acetaminophen and neurodevelopmental disorders.

A 2025 review of 46 earlier studies that Mr. Baccarelli participated in 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.