U.S. Health and Human Services Secretary Robert F. Kennedy Jr., looks on as he attends to testify before a Senate Finance Committee hearing on President Donald Trump's 2026 health care agenda, on Capitol Hill in Washington, D.C., U.S., September 4, 2025. REUTERS/Jonathan Ernst

By Michael Erman and Julie Steenhuysen

(Reuters) - U.S. Health Secretary Robert F. Kennedy Jr. plans to announce that use of Kenvue's popular over-the-counter pain medication Tylenol in pregnant women is potentially linked to autism, The Wall Street Journal reported on Friday, citing people familiar with the matter, without including evidence for the claims.

Kennedy, in a report, will also suggest a medicine derived from folate called folinic acid can be used to treat symptoms of autism in some people, the WSJ reported.

Shares of Kenvue fell 14% after the report. Tylenol, whose active ingredient is acetaminophen, is a widely used pain reliever, including by pregnant women.

The report, expected this month from the U.S. Department of Health and Human Services, which Kennedy heads, is likely to highlight how low levels of folate, an important vitamin, and Tylenol taken during pregnancy, could be a potential cause of autism, the report said.

Kenvue said in a statement that it believes there is no causal link between Tylenol use during pregnancy and autism. The company advises expecting mothers to speak to healthcare professionals before taking OTC medications, including Tylenol.

The U.S. Food and Drug Administration and leading medical organizations agree on the safety of acetaminophen, its use during pregnancy, and the information provided on the label," the company said.

HHS declined to comment.

It is not the first time Kenvue or J&J have faced questions about a link between Tylenol and the condition. In December 2023, a U.S. federal judge struck a blow to hundreds of lawsuits claiming a Tylenol can cause autism if mothers take it during pregnancy, barring expert witnesses from testifying after finding they lacked scientific evidence for their claims.

Last August, citing that ruling, the judge dismissed all the cases in federal court. A U.S. appeals court is slated to hear arguments next month in an appeal of that ruling, court records show.

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Children's Health Defense, the anti-vaccine group formerly headed by Kennedy, has posted several times in recent weeks on social media site X about the potential link between Tylenol and autism.

They cited a study published in August that found evidence of an association between use of acetaminophen by pregnant women and neurodevelopmental disorders such as autism in their offspring.

The scientists recommended medical guidelines advise that pregnant women use the lowest possible dose for the shortest time needed.

They noted that more studies were required to confirm any association and that failure to treat fever in pregnant women could lead to other fetal problems, such as neural tube defects.

Other studies have not found a link. A 2024 study published in the Journal of the American Medical Association of 2.4 million children born in Sweden found no evidence to support a causal link between the pain reliever use during pregnancy and the risk of autism.

"There is no clear evidence that proves a direct relationship between the prudent use of acetaminophen during pregnancy and fetal developmental issues. Neurodevelopmental disorders, in particular, are multifactorial and very difficult to associate with a singular cause," said Christopher Zahn, chief of clinical practice for the American College of Obstetricians and Gynecologists.

(Reporting by Puyaan Singh in Bengaluru and Michael Erman in New Jersey, Additional reporting by Julie Steenhuysen in Chicago and Nancy Lapid in Tucson; Editing by Vijay Kishore and Aurora Ellis)