Kenvue, the maker of Tylenol, along with major pharmacy chains, retailers and other defendants, is asking a U.S. appeals court to take another look at its decision allowing more than 500 lawsuits alleging that the painkiller is linked to autism to move forward.
In a filing with the 2nd U.S. Circuit Court of Appeals in Manhattan, the defendants argued that the court should have deferred to a lower-court ruling that barred testimony from three medical experts whose opinions connected acetaminophen use during pregnancy with autism and attention deficit hyperactivity disorder (ADHD).
The companies contend that the original decision failed to give sufficient weight to federal evidence rules, which require judges to act as gatekeepers when determining whether expert testimony is scientifically reliable enough to reach a jury.
They warned that leaving the question to jurors would effectively ask people without scientific expertise to resolve complex and unsettled medical issues. The defendants described the plaintiffs’ underlying theory as unsupported and argued that scientific reliability should be determined before such evidence reaches trial.
The dispute stems from a ruling by U.S. District Judge Denise Cote in Manhattan, who had excluded testimony from Andrea Baccarelli, dean of Harvard’s public health school; Eric Hollander, a psychiatry professor at the Albert Einstein College of Medicine; and toxicologist Brandon Pearson, formerly associated with Columbia University.
An appeals court decision on July 13 revived the lawsuits, prompting the defendants to seek reconsideration. If the court declines to reverse that ruling, the companies have asked it to clarify that the experts’ opinions should not automatically be treated as admissible and to send the matter back to Cote for further review.
The defendants include Kenvue and a broad group of retailers and pharmacy operators, among them Albertsons, Costco, CVS, Dollar General, Dollar Tree, Family Dollar, Kroger, Target, Walgreens and Walmart.
Reconsideration requests are rarely granted by the appeals court.
The legal battle comes amid continuing debate over acetaminophen, the active ingredient in Tylenol. Doctors and medical organizations have generally regarded the medicine as a preferred option for treating pain and fever during pregnancy. At present, there is no established scientific evidence demonstrating that acetaminophen causes autism or ADHD.
The issue gained additional political attention after President Donald Trump and senior U.S. health officials publicly raised concerns about a possible connection last year.
Kenvue, headquartered in Summit, New Jersey, became an independent company after being spun off from Johnson & Johnson in 2023.
