Shares of Kenvue fell more than 10% on Friday after a report that Health and Human Services Secretary Robert F. Kennedy Jr. will likely link autism to the use of the company's pain medication Tylenol in pregnant women.
HHS will release the report that could draw that link this month, the Wall Street Journal reported on Friday.
That report will also suggest a medicine derived from folate – a water-soluble vitamin – can be used to treat symptoms of the developmental disorder in some people, according to the Journal.
In a statement, an HHS spokesperson said "We are using gold-standard science to get to the bottom of America's unprecedented rise in autism rates."
"Until we release the final report, any claims about its contents are nothing more than speculation," they added.
Tylenol could be the latest widely used and accepted treatment that Kennedy has undermined at the helm of HHS, which oversees federal health agencies that regulate drugs and other therapies. Kennedy has also taken steps to change vaccine policy in the U.S., and has amplified false claims about safe and effective shots that use mRNA technology.
Kennedy has made the disorder a key focus of HHS, pledging in April that the agency will "know what has caused the autism epidemic" by September and eliminate exposures. He also said that month that the agency has launched a "massive testing and research effort" involving hundreds of scientists worldwide that will determine the cause.
In a statement, Kenvue said it has "continuously evaluated the science and [continues] to believe there is no causal link" between the use of acetaminophen, the generic name for Tylenol, during pregnancy and autism.
The company added that the Food and Drug Administration and leading medical organizations "agree on the safety" of the drug, its use during pregnancy and the information provided on the Tylenol label.
The FDA website says the agency has not found "clear evidence" that appropriate use of acetaminophen during pregnancy causes "adverse pregnancy, birth, neurobehavioral, or developmental outcomes." But the FDA said it advises pregnant women to speak with their health-care providers before using over-the-counter drugs.
The American College of Obstetricians and Gynecologists maintains that acetaminophen is safe during pregnancy when taken as directed and after consulting a health-care provider.
Some previous studies have suggested the drug poses risks to fetal development, and some parents have brought lawsuits claiming that they gave birth to children with autism after using it.
But a federal judge in Manhattan ruled in 2023 that some of those lawsuits lacked scientific evidence and later ended the litigation in 2024. Some research has also found no association between acetaminophen use and autism.
In a note on Friday, BNP Paribas analyst Navann Ty said the firm believes the "hurdle to proving causation [between the drug and autism] is high, particularly given that the litigation previously concluded in Kenvue's favor."
-- CNBC's Angelica Peebles contributed to this report.
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