Tylenol maker’s stock dips after report says RFK Jr.’s HHS plans to link the drug to autism

The U.S. Department of Health and Human Services is planning to release a report that will reportedly link autism and acetaminophen use in pregnancy, according to The Wall Street Journal. The department has confirmed a report is in the works, but has not revealed its conclusions.

Drug maker Kenvue, which sells acetaminophen under the brand name Tylenol, saw its shares slump following the Journal’s report, dropping more than 10% on Friday.

Health Secretary Robert F. Kennedy Jr. ihas made investigating autism a cornerstone of his efforts at the department. According to the Journal, the report will also make a link between folate deficiency and autism. But in statements to other media outlets, an HHS spokesperson said the Journal’s reporting was “speculation.”

“We are using gold-standard science to get to the bottom of America’s unprecedented rise in autism rates,” a spokesperson for the department said.

What the science says about acetaminophen and autism

Some studies have found correlations between taking the common painkiller in pregnancy and the risk of children developing neurodevelopmental conditions. But these studies don’t prove a link, and other results suggest otherwise: A 2024 Journal of the American Medical Association (JAMA) study—the largest on acetaminophen to date—found that there was no association between acetaminophen use during pregnancy and increased risk of autism, attention deficit and hyperactivity disorder, or intellectual disability.

The report comes months after Kennedy promised HHS would undertake a “massive testing and research effort” to find a cause for autism as soon as September. A mountain of research suggests that autism has no single cause, but is likely a combination of factors, including genetics. Kennedy has since walked that timeline back, telling CNN, “it will probably take us another six months.”

No proven link

Tylenol’s maker Kenvue told Fast Company in a statement that there is no proven link between acetaminophen and autism.

“To date, the U.S. Food and Drug Administration (FDA) and leading medical organizations agree on the safety of acetaminophen, its use during pregnancy, and the information provided on the label.” “We advise expecting mothers to speak to their healthcare professionals before taking any over-the-counter medications, including acetaminophen, as they are best positioned to advise their patients on whether taking acetaminophen is appropriate based on their unique medical conditions.”

The FDA has not found any “clear evidence” that acetaminophen during pregnancy “causes adverse pregnancy, birth, neurobehavioral, or developmental outcomes.” It also recommends that pregnant persons talk to their care providers before using any medications.

Fast Company reached out to the department of Health and Human Services for comment, but did not hear back by the time of publication.