Hundreds of Tylenol autism lawsuits remain revived after a federal appeals court rejected Kenvue’s request to reconsider the decision that brought them back to life.
The U.S. Court of Appeals for the Second Circuit on October 16 denied both panel rehearing and rehearing en banc, which would have put the case before the full court, Reuters reported. The brief order leaves intact a July ruling reviving about 500 lawsuits over claims that taking acetaminophen during pregnancy caused autism or attention-deficit/hyperactivity disorder in children.
The development is another procedural setback for the Tylenol maker. It is not a finding that the drug causes either condition, and the families still must prove their claims.
What the Tylenol lawsuits allege
The families contend that manufacturers and retailers failed to warn about alleged risks from prenatal exposure to acetaminophen, the active ingredient in Tylenol and generic versions of the over-the-counter pain reliever. Their cases were consolidated in federal court in New York before U.S. District Judge Denise Cote.
Judge Cote excluded the plaintiffs’ expert testimony on whether the drug can cause autism or ADHD, leading to judgments for the defendants. Without admissible evidence of that general causal relationship, the cases could not proceed.
Why the appeals court revived the cases
In its July 13 opinion, the Second Circuit found that Judge Cote exceeded her discretion in excluding three experts: Andrea Baccarelli, Eric Hollander and Brandon Pearson. The panel upheld the exclusion of two others.
The dispute centers on how judges screen scientific testimony. The panel concluded that the three experts used accepted methods and offered permissible interpretations of contested evidence. It also rejected the defendants’ argument that federal labeling requirements preempted the families’ failure-to-warn claims.
Kenvue sought reconsideration, arguing that trial judges are responsible for deciding whether scientific evidence is reliable enough to reach a jury, according to Reuters. Friday’s denial could set up a request for U.S. Supreme Court review.
Trump administration warnings added political attention
The litigation gained a larger public profile in September 2025 when President Donald Trump, appearing with Health and Human Services Secretary Robert F. Kennedy Jr., urged pregnant women to avoid Tylenol.
The administration backed a more precautionary approach. On September 22, 2025, the FDA announced it was initiating a labeling-change process to address a possible association between acetaminophen use during pregnancy and autism or ADHD. It also notified physicians of the concern.
But the FDA’s announcement included an important qualification: studies reporting an association had not established a causal relationship, and other studies reached contrary results. The agency also acknowledged that high fevers during pregnancy can pose risks and that acetaminophen may remain appropriate in some circumstances.
Medical groups pushed back against the broader warnings. The American College of Medical Toxicology said the evidence did not establish that acetaminophen causes autism and warned that discouraging its use could leave pregnant patients with untreated fever or pain.
Kenvue continues to dispute the claims
In its statement responding to the July ruling, Kenvue said independent scientific evidence showed no proven link between acetaminophen and autism or ADHD. The company said it would continue defending the cases and challenging the plaintiffs’ expert opinions.
For the families, the rehearing denial preserves the opportunity to pursue litigation that had been dismissed. The central question of whether they can establish causation and liability remains unresolved.
