FILE PHOTO: An illustration photo shows boxes of Tylenol in Schwenksville, Pennsylvania, U.S. September 24, 2025. REUTERS/Hannah Beier/File Photo/File Photo

By Diana Novak Jones

CHICAGO (Reuters) -A U.S. appeals court is expected to hear arguments on Monday from families seeking to revive their lawsuits over Tylenol, after the Trump administration publicly promoted their claims that the popular painkiller is linked to autism in children.

In urging the appeals court to reinstate more than 500 lawsuits seeking damages from Tylenol maker Kenvue, the plaintiffs cited a September press conference where President Donald Trump and his top health officials linked autism to Tylenol use.

A lower-court judge tossed out the lawsuits in 2024 after criticizing the methods of the experts the plaintiffs put forward to support their claims.

Researchers say there is no firm evidence of a link between autism and the use of Tylenol or its generic equivalent, acetaminophen. Kenvue has said that science shows Tylenol is safe and taking acetaminophen does not cause autism.

A spokesperson for Kenvue said the company believes the lower court's ruling on the experts was correct.

An attorney for the plaintiffs did not respond to a request for comment. The plaintiffs have argued that the lower-court judge did not properly consider the experts' opinions.

It is not clear whether a ruling by the 2nd U.S. Circuit Court of Appeals reviving the cases would have major implications for the planned acquisition of Kenvue by Kimberly-Clark, which announced on November 3 that it will pay more than $40 billion to buy the former Johnson & Johnson unit. The deal is set to close next year.

In documents laying out the plan for the merger filed with the U.S. Securities and Exchange Commission, the companies said that any "condition, development or occurrence" related to allegations of a link between autism or attention deficit hyperactivity disorder (ADHD) and Tylenol use in pregnancy would not be a reason for Kimberly-Clark to back out of the agreement.

Kenvue is separately defending a lawsuit brought by Texas Attorney General Ken Paxton that alleges the company concealed risks to children from the use of Tylenol by pregnant women. On Friday, a Texas judge declined Paxton's request to block Kenvue from paying its scheduled $398 million shareholder dividend later this month.

The judge also rejected Paxton's request to temporarily order Kenvue to modify its marketing.

In December 2023, U.S. District Judge Denise Cote in Manhattan, who is overseeing the centralized litigation over the families' claims against Kenvue, wrote that expert witnesses put forth by the plaintiffs "obscured the complexities, inconsistencies, and weaknesses in the underlying data."

The plaintiffs appealed in April 2024, and after the White House press conference they sent the appeals court a letter urging it to consider Trump's comments.

(Reporting by Diana Novak Jones; Editing by Amy Stevens and Edmund Klamann)