The Donald Trump administration announced that Tylenol (acetaminophen), the world's most widely used painkiller, may cause autism. The announcement directly contradicts existing medical guidance that has recommended Tylenol as the safest analgesic and antipyretic for pregnant women. The medical community and experts immediately pushed back, calling it "a claim for which causality has not been proven" and saying it "could put pregnant women and fetuses at greater risk."
On the 22nd (local time), President Trump held a press conference at the White House and warned that pregnant women should refrain from using acetaminophen unless they have a high fever. At the same time, he said the U.S. Food and Drug Administration (FDA) plans to approve leucovorin, a form of folate (vitamin B), as a treatment for certain symptoms in some children with autism. Earlier, at Charlie Kirk's memorial service on the 21st, President Trump said, "We seem to have found the answer to autism," previewing the announcement.
The announcement is known to have been led by Robert F. Kennedy Jr., Minister of Health and Human Services (HHS). In April this year, he had already pledged to "find the cause of the autism epidemic by September."
The medical community immediately pushed back. Major medical organizations, including the American College of Obstetricians and Gynecologists (ACOG) and the Royal College of Obstetricians and Gynaecologists (RCOG), currently recommend acetaminophen as a "first-line medication" for pain and fever during pregnancy. It is known that failing to treat high fever during pregnancy can increase the risk of serious congenital disorders, such as heart disease and neural tube defects. Peter Bernstein, Commissioner of ACOG's Clinical Consensus Committee, told Politico that "the studies in question merely look for associations, not causality," adding that "not treating high fever can pose a much greater risk to pregnancy than taking Tylenol."
Research on the association between acetaminophen and autism has been underway for decades, but results are mixed. Some observational studies have shown statistical associations, but experts emphasized that it is unclear whether this is due to the drug itself or other confounding variables such as genetics or maternal illness. In fact, a large-scale 2024 study of about 2.5 million children in Sweden concluded there is no causal relationship between acetaminophen exposure and autism.
Kenvue, the maker of Tylenol, immediately released a statement saying, "Independent and sound science clearly shows that taking acetaminophen does not cause autism," and "we strongly oppose any other suggestion and are deeply concerned about the health risks this announcement may pose to pregnant women." After the Wall Street Journal (WSJ) first reported the Trump administration's plan, Kenvue's share price plunged 16%.
The announcement also comes against the backdrop of recent litigation in the United States. Hundreds of parents and autism activists filed lawsuits against retailers, saying Tylenol failed to warn that it could cause autism. However, in Dec. 2023, a U.S. federal court barred expert testimony due to a lack of scientific evidence. Based on that ruling, all lawsuits filed in federal court in Aug. last year were dismissed.