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Trump blames Tylenol for autism. Science doesn't back him up

President Trump takes questions the White House, following an announcement that federal health officials are updating drug labelling to discourage the use of Tylenol during pregnancy.
Andrew Harnik
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President Trump takes questions the White House, following an announcement that federal health officials are updating drug labelling to discourage the use of Tylenol during pregnancy.

Updated September 22, 2025 at 8:38 PM CDT

In a White House press conference Monday, President Trump and several deputies said the Food and Drug Administration would be updating drug labelling to discourage the use of acetaminophen by pregnant women, suggesting a link between the common painkiller and autism.

Federal officials also said they would also be changing the label for leucovorin, a form of vitamin B typically used in conjunction with cancer treatment, to enable its use as a treatment for autism. And they added that state Medicaid programs, in partnership with the federal Centers for Medicare and Medicaid Services, would cover this use.

The suite of changes were announced despite a notable lack of clear scientific evidence to support these moves. They were presented as part of what the administration said was its commitment to identify the root causes of autism, diagnoses of which have increased in recent years.

Flanked by Health and Human Services Secretary Robert F. Kennedy Jr. and Centers for Medicare and Medicaid head Dr. Mehmet Oz, President Trump pinned substantial blame for rising autism rates on the common painkiller, which is also known by its brand name, Tylenol.

"Taking Tylenol is not good — I'll say it: It's not good," he said, suggesting without evidence that communities without access to the medicine have "no autism," while in others, autism now affects one in 12 boys. (An estimated 1 in 31 children in the U.S. are diagnosed with autism.) Trump also discouraged giving acetaminophen to babies, as well. (He also suggested that vaccines and their frequency may be a culprit in causing autism, an oft-repeated claim that has been debunked by decades of research.)

Trump and his deputies repeatedly advised pregnant women to refrain from using acetaminophen, and said they would caution physicians against using it — contrary to what physicians' groups say.

In a statement sent to NPR, Tylenol maker Kenvue disputed the administration's claims.

"We believe independent, sound science clearly shows that taking acetaminophen does not cause autism," the statement said. "We strongly disagree with any suggestion otherwise and are deeply concerned about the health risks and confusion this poses for expecting mothers and parents."

During the press conference, officials pointed to a study done by Harvard University and other researchers that found that women who reported taking acetaminophen while they were pregnant seemed to be slightly more likely to have a child who was later diagnosed with autism.

One of the researchers on that study was Ann Bauer, an epidemiologist at the University of Massachusetts. Bauer said she thinks pregnant women should be told about a possible risk from acetaminophen. But the researcher also was worried that it might be too soon to have the federal government offering guidance on its use.

"I'm a little concerned about how this message is going to come because I think they may be jumping the gun," Bauer said before the announcement was made. "I think those of us in the research community would like to see stronger evidence."

Diagnoses of autism have risen over the past two decades, though use of acetaminophen has not — remaining largely steady over that time. The increase in diagnoses is often attributed to a broadened definition of autism, with changes in the diagnostic criteria, as well as increased awareness and screening, but Kennedy dismissed those explanations as a "canard."

Many physicians and autism advocacy groups said they opposed the administration's stance.

"It is highly unsettling that our federal health agencies are willing to make an announcement that will affect the health and well-being of millions of people without the backing of reliable data," Steven J. Fleischman, MD, president of the American College of Obstetricians and Gynecologists, said in a written statement.

Even the notice about acetaminophen issued to physicians by the Food and Drug Administration pointed out that a possible link to autism was an area of ongoing scientific debate, and said that "while an association between acetaminophen and autism has been described in many studies, a causal relationship has not been established and there are contrary studies in the scientific literature."

Specifically, the Food and Drug Administration, as well as the agency that sets policy for Medicare and Medicaid, pledged to change the indication on a medication called leucovorin as a treatment for autism, despite scant evidence that this form of vitamin B has any effect.

In response to that change, the American Psychiatric Association issued a statement opposing the administration's suggestion that vaccines cause autism, adding that leucovorin (folinic acid) is not recommended to treat autism, adding "it will require many more years of research before we know if leucovorin is an appropriate treatment for individuals with autism."

But, by his own admission, President Trump said he was not precise with his language on the subject. But he repeated the same message multiple times during his remarks.

"If you can't tough it out," President Trump said, limited use of acetaminophen might be necessary. But "ideally you don't take it at all," he said, in a rambling press conference that at times conflated vaccine and painkiller use, citing both unconfirmed rumors and personal suppositions that both might be harmful to women and babies.

"It looks like you're pumping it into a horse," Trump said of multiple vaccinations given to children. "The Amish, for example, have no autism," he said, despite research showing that autism does affect Amish communities, later adding that there are no cases of autism in Cuba, when in fact there are cases of autism there. He called on pregnant women to refrain from using the common painkiller, repeatedly saying "Don't take Tylenol."

"There's no downside," he maintained, although pregnant women are told to avoid other anti-fever drugs such as aspirin and ibuprofen, and fever can be dangerous in a pregnancy. The Society for Maternal-Fetal Medicine, which recommends using acetaminophen to treat fever and pain in pregnant women, says that untreated fever can cause grave harms such as miscarriage, birth defects or premature birth, especially early in a pregnancy.

Merck, maker of various vaccines including for measles, pneumonia and HPV, also responded, saying, "the recent statement that vaccines could be linked to autism is inconsistent with the extensive scientific studies that have been conducted over the past 25 years, which have consistently shown no link between vaccination and autism."

"Today's announcement risks taking us backwards," said Jackie Dilworth, a spokesperson for The Arc of the United States, a group representing people with developmental disabilities and their families. "Today's claims risk fueling stigma, misleading the public, and distracting from what families truly need," because they present unproven suppositions as fact, she said.

Copyright 2025 NPR

Jon Hamilton is a correspondent for NPR's Science Desk. Currently he focuses on neuroscience and health risks.
Yuki Noguchi is a correspondent on the Science Desk based out of NPR's headquarters in Washington, D.C. She started covering consumer health in the midst of the pandemic, reporting on everything from vaccination and racial inequities in access to health, to cancer care, obesity and mental health.
Nell Greenfieldboyce is a NPR science correspondent.