Families whose lawsuits claim that Tylenol or its generic versions caused autism in their children are asking a federal appeals court to reconsider after President Donald Trump recently advised pregnant women to avoid the painkiller. The appeals involve hundreds of cases that were dismissed last year due to a lack of solid scientific evidence connecting acetaminophen—the active ingredient in Tylenol—to autism or ADHD.
Ashley Keller, an attorney for the families, sent a letter to the 2nd U.S. Circuit Court of Appeals in New York, pointing out the Trump administration’s recent stance. At a White House press conference, Trump urged pregnant women not to use acetaminophen, citing research on the potential link between the drug and neurodevelopmental disorders. This research was highlighted by U.S. Food and Drug Administration Commissioner Marty Makary and Health Secretary Robert F. Kennedy Jr. They referenced work by Andrea Baccarelli, a Harvard scientist who is one of the plaintiffs’ experts in the Tylenol cases.
Last year, U.S. District Judge Denise Cote threw out more than 500 lawsuits, ruling that the experts brought in by the families did not use reliable scientific methods. The judge said their approach seemed biased and selective, which weakened their claims. Product liability cases like these rely heavily on expert testimony to show a product caused harm. So far, no court has found the evidence strong enough to move forward.
Kenvue, the company behind Tylenol, responded by saying they expect to win in court because the claims lack legal and scientific support. Their lawyer also pointed out that the FDA issued a note to doctors alongside Trump’s press conference, making it clear that no causal link between acetaminophen and autism has been proven. Baccarelli himself acknowledged that more research is needed to confirm any connection and to understand cause and effect.
The 2nd Circuit had planned to hear oral arguments on October 6 but postponed them until November. Legal experts say it’s unlikely the court will give much weight to the President’s public statements or the administration’s position since no new studies have emerged to change the science.
Researchers outside the case agree there’s no firm proof linking Tylenol use during pregnancy to autism. A large 2024 study involving nearly 2.5 million children in Sweden found no causal connection. Another review from 2025, which included Baccarelli, suggested there might be an increased risk tied to prenatal acetaminophen exposure, but it didn’t prove the drug actually caused these conditions.
For now, the debate continues in court, while families and companies await further legal and scientific developments.