Trump links autism to Tylenol and vaccines, claims not backed by science

US President Donald Trump has linked autism to childhood vaccine use and the taking of pain medication Tylenol by women when pregnant, elevating claims not backed by scientific evidence to the forefront of US health policy.

In an extraordinary news conference at the White House, the Republican president delivered medical advice to pregnant women and parents of young children, repeatedly telling them not to use or administer the painkiller and suggesting that common vaccines not be taken together or so early in a child's life.

The advice from Trump, who acknowledged he is not a doctor, goes against that of medical societies, which cite data from numerous studies showing that acetaminophen, the active ingredient in Tylenol, plays a safe role in the well-being of pregnant women.

"I want to say it like it is, don't take Tylenol. Don't take it," Trump said. "Other things that we recommend, or certainly I do anyway, is... don't let them pump your baby up with the largest pile of stuff you've ever seen in your life," he said, referring to vaccines.

The widely used over-the-counter pain relief medication is also known generically as paracetamol elsewhere.

Trump's team suggested leucovorin, a form of folinic acid, as a treatment for autism symptoms.

Dozens of medical, research and autism advocacy groups, including the American Academy of Pediatrics and the American College of Obstetricians and Gynecologists, decried the president's announcement. "The data cited do not support the claim that Tylenol causes autism and leucovorin is a cure, and only stoke fear and falsely suggest hope when there is no simple answer," the Coalition of Autism Scientists said in a statement.

Standing with Health Secretary Robert F. Kennedy Jr., a vaccine critic who has argued that no vaccine is safe, Trump called for a reexamination of a link between vaccines and autism, a theory that has been repeatedly debunked. "We believe independent, sound science clearly shows that taking acetaminophen does not cause autism. We strongly disagree with any suggestion otherwise and are deeply concerned with the health risk this poses for expecting mothers and parents," Kenvue, the maker of Tylenol, said in a statement.

Britain's health regulator said on Monday it is safe to use the pain relief treatment paracetamol and that there is no evidence of it causing autism in children. The Trump administration has asked drug companies to be prepared to ramp up production of leucovorin as a treatment for some autism patients, Food and Drug Administration chief Marty Makary told reporters.

The FDA has approved a version of the drug made by GSK that was aimed at treating a condition associated with autism, but which the drugmaker no longer manufactures. Once it is established for the use, the administration said Medicaid insurance for low-income people would cover the drug for autism symptoms.

The FDA, in its approval process, cited a review of the use of leucovorin in 40 patients with a rare metabolic disorder called cerebral folate deficiency that can lead to a range of neurological symptoms, some of which are seen in people with autism.

The FDA said it would seek a label change for over-the-counter Tylenol and its generic versions to reflect evidence suggesting that use during pregnancy may be associated with an increased risk of neurological conditions such as autism and ADHD in children. The FDA also sent a letter to doctors with a similar warning, but said a causal relationship had not been established.

Researchers say there is no firm evidence of a link between the use of Tylenol and autism. A 2024 study of nearly 2.5 million children in Sweden found no causal link between in utero exposure to acetaminophen and neurodevelopmental disorders.