By Liz Essley Whyte

WASHINGTON -- The Food and Drug Administration moved to approve a version of a little-known medicine that the Trump administration is planning to tout as a treatment for autism symptoms, according to a public document and people familiar with the matter.

The move coincides with an event at the White House on Monday afternoon, when the administration is expected to warn that acetaminophen, the active ingredient in Tylenol, is a potential cause of autism, according to people familiar with the event. Officials are expected to point to the medicine known as leucovorin as a way to help alleviate autism symptoms in some people, and the National Institutes of Health is expected to announce the grants awarded under its autism data-science initiative.

President Trump previewed the White House event during a memorial service for slain conservative activist Charlie Kirk. "Tomorrow we're going to have one of the biggest announcements medically, I think, in the history of our country," Trump said. "I think we found an answer to autism."

At the White House on Monday, officials are expected to lay out potential regulatory actions related to health officials' findings, including labeling changes for acetaminophen and the new approval for leucovorin. The Wall Street Journal reported this month that the administration planned to link autism to Tylenol use, as part of Health Secretary Robert F. Kennedy Jr. hunt for the cause of autism.

The American College of Obstetricians and Gynecologists says acetaminophen is safe to use in pregnancy, though it recommends that pregnant women consult with their doctors before using it, as with all medicines.

"We believe independent, sound science clearly shows that taking acetaminophen does not cause autism," said a spokeswoman for Kenvue, the parent company of Tylenol's maker. "We strongly disagree with any suggestion otherwise and are deeply concerned with the health risk this poses for expecting mothers."

The FDA early Monday published a notice saying that it is approving a version of leucovorin that was previously made by GlaxoSmithKline. But later in the morning the Federal Register received an "agency letter" asking to withdraw the notice, according to a statement on the Federal Register website. The statement didn't include the agency's rationale for withdrawing the notice.

A spokesman for the Department of Health and Human Services declined to comment.

In the withdrawn notice, the FDA said it had reviewed scientific studies from 2009 to 2024 and found that leucovorin improves certain symptoms in some patients with cerebral folate deficiency, including patients with "autistic features."

Leucovorin is chemically related to vitamin B9, or folate. It is currently used to help patients with side effects from chemotherapy.

Small studies involving a few dozen children each have reported language or behavioral improvements in children with autism who take leucovorin. Autism researchers have said the treatment shows some promise but that the early studies aren't yet adequate to tell whether the medicine can help many people.

The NIH is leading a report on the causes of autism that was expected to be a review of existing scientific literature and be released on Sept. 29 , according to people familiar with the matter. It is unclear whether the full report will still be released, or when.

Write to Liz Essley Whyte at liz.whyte@wsj.com

(END) Dow Jones Newswires

September 22, 2025 13:01 ET (17:01 GMT)

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