Tylenol Autism Spectrum Disorder Lawsuit Timeline: Second Circuit Revives More Than 500 Cases 

On July 13, 2026, the U.S. Court of Appeals for the Second Circuit revived more than 500 lawsuits accusing Tylenol maker Kenvue Inc. of hiding the risk that acetaminophen use during pregnancy could contribute to autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD) in children. The unanimous ruling reverses a lower court decision that had effectively shut down the federal litigation in 2023, and it clears the way for the cases to move toward trial. 

For families who took Tylenol while pregnant and later had a child diagnosed with autism or ADHD, this ruling is a significant development. Below, we walk through how the litigation reached this point, what the court actually decided, and what may come next. 

Timeline of the Tylenol Autism/ADHD Litigation 

2022: The Federal Litigation Is Consolidated 

Lawsuits filed across the country alleging that prenatal acetaminophen exposure is linked to autism and ADHD were consolidated into a single multidistrict litigation (MDL) in the U.S. District Court for the Southern District of New York, captioned In re: Acetaminophen ASD-ADHD Products Liability Litigation, No. 1:22-md-03043. Kenvue, the Johnson & Johnson consumer health spinoff that manufactures Tylenol, along with several major retailers, including CVS, Kroger, Target, Walgreens, and Walmart, were named as defendants. 

Late 2023: The Cases Are Dismissed 

U.S. District Judge Denise Cote ruled that the plaintiffs’ expert witnesses had relied on unreliable methodologies to connect acetaminophen to autism and ADHD. Acting as the “gatekeeper” required under federal evidence rules, Judge Cote excluded the testimony of several key experts and dismissed roughly 500 cases from moving forward toward trial. 

September 2025: The Issue Becomes a National Story 

The controversy resurfaced in a major way when President Donald Trump and federal health officials publicly linked Tylenol use during pregnancy to autism, urging expectant mothers to avoid the medication. The FDA subsequently notified physicians it was updating labeling guidance, even as it acknowledged that a causal relationship had not been established. Major medical groups pushed back, continuing to describe acetaminophen as a safe, preferred option for treating pain and fever during pregnancy. 

November 18, 2025: Oral Arguments at the Second Circuit 

A three-judge panel of the Second Circuit heard oral arguments in the consolidated appeals, Rutledge v. Walgreens Co. (No. 24-916) and Phippen v. Walgreens Co. (No. 24-2594). During arguments, the panel focused heavily on the testimony of Dr. Andrea Baccarelli, dean of Harvard’s T.H. Chan School of Public Health, whose Bradford Hill-based causation analysis anchored the plaintiffs’ case. Kenvue’s shares dipped as the market weighed the possibility that the litigation could be revived. 

July 13, 2026: The Second Circuit Reverses and Remands 

In a 64-page decision, Circuit Judges Eunice Lee, Gerard Lynch, and Guido Calabresi unanimously held that Judge Cote had exceeded her gatekeeping role by excluding the testimony of Dr. Baccarelli and two other experts, psychiatrist Dr. Eric Hollander and toxicologist Dr. Brandon Pearson. The panel found that these experts had applied methodologies consistent with standard practices in their fields, and that reasonable scientists can, and do, disagree on causation without any one interpretation being inherently unreliable. 

Notably, the court took pains to clarify what it was no deciding: the ruling doesn’t determine whether acetaminophen actually causes autism or ADHD, and it doesn’t address what public health policy should be. It is a ruling about the admissibility of expert evidence, not a scientific verdict. The cases were sent back to the district court for further proceedings. 

What’s Next 

With the expert testimony reinstated, the more than 500 revived federal cases can proceed toward further litigation, including the possibility of bellwether trials. 

What This Ruling Means If You Were Affected 

This decision doesn’t declare that Tylenol causes autism or ADHD, and Kenvue continues to maintain that no reliable science supports that link. What it does mean is that families who believe their child’s autism or ADHD diagnosis may be connected to acetaminophen use during pregnancy will now get the chance to have their evidence heard, rather than having their case dismissed before a jury ever sees it. 

If you took Tylenol or a generic acetaminophen product while pregnant and your child was later diagnosed with autism spectrum disorder or ADHD, it’s worth understanding your legal options. Litigation like this can take time, and deadlines to file a claim vary, so early evaluation matters. 

Napoli Shkolnik is currently reviewing potential Tylenol autism/ADHD claims.  

Contáctenos for a free, confidential case review to find out whether your family may qualify.