Jornal Do Brasilia - US appeals court revives private cases alleging Tylenol link to autism

Judges at Manhattan's second circuit of appeals sent the previously dismissed cases back to a lower court for further proceedings, after ruling that a district judge had improperly excluded expert witness testimony.

The plaintiffs argue that Tylenol use during pregnancy can lead to autism or attention deficit hyperactivity disorder in children.

Scientific research has not identified causality between taking the painkiller and the development of those conditions in children.

The issue came into the spotlight last year as US President Donald Trump vehemently urged pregnant women not to take Tylenol over the unsubstantiated link to autism.

Some public health experts have described Trump's attacks on the drug as unscientific and dangerous.

Acetaminophen is the primary active ingredient in over-the-counter medications including Tylenol.

It is considered the safest option for treating pain and fever in pregnant women, as other medications, including aspirin or ibuprofen, present proven risks to the fetus -- as do untreated fevers.

The judges behind Monday's ruling emphasized that their decision in no way offered scientific advice or the basis for public health policy.

"We are not deciding whether there is a general causal relationship between acetaminophen and ADHD and/or ASD," they wrote. "And we are certainly not deciding the approach that policymakers concerned with protecting public health should take to regulating the use of acetaminophen."

Their role, they said, was to determine whether certain expert testimony should have been admitted. And they ruled that "the district court exceeded its discretion" in excluding some of the plaintiffs' expert witnesses.

A Kenvue spokesperson told AFP that the procedural ruling "does not change the fact that credible, independent science shows no proven link between taking acetaminophen and autism or attention deficit hyperactivity disorder (ADHD)."

"Science matters, and we stand with the many public health and medical professionals who have reviewed the science on this topic and agree. We now have another opportunity to show that the plaintiffs' experts' opinions are unreliable and should not be allowed in this case."

Kenvue was spun off from Johnson & Johnson, which had sold Tylenol for decades, in 2023.

It was announced in 2025 that Kimberly-Clark, the paper and personal care products giant, would acquire Kenvue.

L. de Freitas--JDB