US Appeals Court Revives 500+ Autism Lawsuits Against Tylenol Maker
Second Circuit reinstates over 500 lawsuits against Kenvue alleging Tylenol-autism link.
Why it matters: This ruling revives large-scale litigation with potential impacts on product liability and corporate risk. It challenges how courts evaluate scientific expert testimony in health-related mass torts.
- Over 500 private lawsuits reinstated against Kenvue on July 13, 2026.
- Appeals court ruled District Judge Denise Cote wrongly excluded expert testimony from three doctors.
- Decision focuses on admissibility of expert evidence, not establishing causation between acetaminophen and autism or ADHD.
- Kenvue maintains no proven scientific link exists between acetaminophen use and neurodevelopmental disorders.
On July 13, 2026, the 2nd U.S. Circuit Court of Appeals in Manhattan revived more than 500 lawsuits against Kenvue, the maker of Tylenol, alleging prenatal use of acetaminophen causes autism spectrum disorder (ASD) or attention-deficit/hyperactivity disorder (ADHD) in children. The court found that U.S. District Judge Denise Cote improperly excluded expert testimony submitted by three physicians: Dr. Andrea Baccarelli, Dr. Eric Hollander, and Dr. Brandon Pearson.
The appeals court emphasized its ruling addresses only the admissibility of expert evidence and does not confirm any causal link. Kenvue disputes the connection, stating that "credible, independent scientific research shows no proven link between taking acetaminophen and autism or attention deficit hyperactivity disorder (ADHD)." Medical professionals widely regard acetaminophen as the preferred treatment for pain and fever during pregnancy.
Plaintiffs' attorney Ashley Keller called the decision "a vindication for the scientific evidence our clients have presented from the outset," signaling renewed momentum for the litigation.
This reversal follows District Judge Cote's December 2024 dismissal over concerns about the reliability of expert witnesses. The reinstatement allows these claims to move forward, potentially influencing product liability practices and increasing corporate risk exposure for pharmaceutical manufacturers, especially with widely used medications.
By the numbers:
- 500+ lawsuits reinstated — against Kenvue by the 2nd U.S. Circuit Court as of July 13, 2026
- $18.76 per share — Kenvue's stock price on July 14, 2026, down 2.44% after ruling
Yes, but: The appeals court decision does not establish a scientific cause-effect relationship; litigation viability hinges on future evidentiary developments.
What's next: The lawsuits will proceed in U.S. District Court, where plaintiffs must present their expert evidence under admissibility standards. Further scientific studies could shape outcomes.