Trump Administration’s Tylenol Warning Sparks Push To Reopen Autism Lawsuits

Case Overview: Families are urging the Second Circuit to revive more than 500 dismissed lawsuits claiming prenatal acetaminophen exposure led to autism or ADHD.

Defendants: Kenvue Inc. and major U.S. retailers of acetaminophen products.

Key Issue: Whether new government statements and research warrant reopening the case.

Court: U.S. Court of Appeals for the Second Circuit

Parents who allege that prenatal exposure to Tylenol or generic acetaminophen contributed to their children’s autism or ADHD diagnoses are asking a federal appeals court to reconsider the dismissal of their lawsuits, Reuters reports.

The request comes after President Donald Trump and senior health officials publicly advised pregnant women to avoid acetaminophen, the active ingredient in Tylenol. Plaintiffs’ attorneys say the administration’s remarks support their argument that the cases were dismissed prematurely.

Plaintiffs Cite Trump-Era Warning As Support For Reviving Dismissed Cases

Attorney Ashley Keller, representing the families, filed a letter with the U.S. Court of Appeals for the Second Circuit on Wednesday. In it, he asked the court to take note of the Trump administration’s recent statements linking acetaminophen use during pregnancy to potential developmental risks.

During a White House press conference on Monday, President Trump, accompanied by U.S. Food and Drug Commissioner Marty Makary and Health Secretary Robert F. Kennedy Jr., warned expectant mothers not to use Tylenol. 

The officials cited research by Andrea Baccarelli, dean of the faculty at the Harvard T.H. Chan School of Public Health—one of the same experts whose testimony had been rejected by the lower court.

Keller argued that the administration’s reliance on Baccarelli’s work contradicts the earlier ruling that excluded his testimony as scientifically unsound. He said upholding the dismissal would raise “grave separation of powers concerns” because the executive branch is now referencing the same research the judiciary discounted.

Defense Says Government Statements Do Not Change The Science

Attorneys for Kenvue, the parent company of Tylenol, responded that the plaintiffs’ argument misrepresents the government’s position. In a filing to the Second Circuit, defense lawyer Jay Lefkowitz noted that the FDA’s advisory accompanying Trump’s remarks reaffirmed that no causal relationship has been established between acetaminophen and autism.

Lefkowitz also cited Baccarelli’s own comments from earlier this week, in which he said that more research is needed to determine whether an association exists. “There is thus no conflict between the government’s action and the district court’s opinion,” Lefkowitz wrote.

Appeals Court Postpones Hearing As Families Seek To Reopen 500 Dismissed Cases

The appeals court had scheduled oral arguments for October 6 but has since postponed the hearing until November. Legal observers expect the panel to review both the procedural and scientific issues before deciding whether to revive the consolidated lawsuits.

The families seek reinstatement of hundreds of cases that were dismissed last year by U.S. District Judge Denise Cote in the Southern District of New York. Judge Cote ruled that the expert witnesses presented by the plaintiffs had not used reliable scientific methods to support claims that acetaminophen could cause autism or ADHD.

In her ruling, Judge Cote dismissed more than 500 complaints filed against Kenvue and several national retailers that sold store-brand acetaminophen. She concluded that the plaintiffs’ experts relied on an “unstructured approach” and “results-driven analysis” that did not meet the standards for admissible scientific testimony.

Because product liability lawsuits require expert evidence to show that a product can cause harm, the dismissal effectively ended the Tylenol autism litigation in federal court—unless the Second Circuit overturns the decision.

Scientific Studies Offer Conflicting Evidence On Acetaminophen And Autism

Research on acetaminophen use during pregnancy has produced mixed findings. A large 2024 study from Sweden examining nearly 2.5 million children found no causal link between prenatal acetaminophen exposure and neurodevelopmental disorders.

By contrast, a 2025 review involving 46 earlier studies—co-authored by Baccarelli and researchers from Harvard University and the Icahn School of Medicine at Mount Sinai—found statistical associations between prenatal exposure and higher rates of autism and ADHD diagnoses. The authors, however, cautioned that their findings did not prove the drug caused those outcomes.

Manufacturers Continue To Deny Any Link To Developmental Disorders

Kenvue and related companies continue to deny that Tylenol or generic acetaminophen products cause developmental disorders. They say the scientific evidence does not support the plaintiffs’ theory and emphasize that acetaminophen remains one of the most widely used and studied medications in the world.

The upcoming appellate hearing will determine whether the families’ lawsuits can proceed or remain dismissed.

Do you believe acetaminophen should include stronger warnings for use during pregnancy? Share your thoughts below.