What You Should Know About Unproven Claims Of Tylenol-Autism Link

Physicians and autism experts across the country are pushing back against claims by President Donald Trump linking Tylenol, vaccines and autism without giving any new evidence.

Also speaking at a news conference Monday, Health Secretary Robert F. Kennedy Jr. said that at Trump’s urging, he is launching an “all-agency” effort to identify the causes of autism involving the National Institutes of Health, the Food and Drug Administration, the Centers for Disease Control and Prevention, and the Centers for Medicare and Medicaid Services.

Autism rates have increased to 1 in 31 children (3.2 percent), up from 1 in 36 children in 2020, according to the CDC. Scientists, doctors and researchers attribute the increase to greater awareness of the disorder, and the newer, wide-ranging “spectrum” used to issue diagnoses for people with milder expressions of autism.

Autism is a complex disorder, and it’s hard to tell if there may be additional factors behind the increase, experts say. They believe there is no single cause, and say the administration’s rhetoric seems to overlook and undermine decades of scientific research into the genetic and environmental factors involved.

Brian Lee, one of the authors of a study debunking a link between autism and acetaminophen, as the drug is generically known, told reporters in a briefing Monday that the claims create “the same sort of chaos” as the CDC vaccine advisory committee’s recent decisions on the MMR vaccine.

“Any time a different voice is added to the conversation, it causes a bit of confusion, especially if the messaging is completely different,” said Lee, a professor of epidemiology and biostatistics at Drexel University.

“The announcement on autism was the saddest display of a lack of evidence, rumors, recycling old myths, lousy advice, outright lies, and dangerous advice I have ever witnessed by anyone in authority in the world claiming to know anything about science,” Arthur Caplan, of the New York University School of Medicine’s Division of Medical Ethics, said in a statement. “What was said was not only unsupported and wrong, but flat out malpractice in managing pregnancy and protecting fetal life.”

Here are five things to know:

What Did Trump Say?

“Don’t take Tylenol, don’t take it,” Trump said. “Fight like hell not to take it.”

He repeated the advice nearly a dozen times, and also encouraged mothers not to give their infants the drug. The president acknowledged the advice was based on his personal views.

“I’m just making these statements from me,” Trump said. “I’m not making them from these doctors. Cause when they, uh, talk about, you know, different results, different studies, I talk about a lot of common sense. And they have that, too. They have that too, a lot.”

Experts, including the American College of Obstetricians and Gynecologists, have long recommended acetaminophen as a safe option during pregnancy. Other pain relief medications, such as ibuprofen, are not recommended during pregnancy and can cause serious harm to a developing baby, especially after 20 weeks.

Untreated fevers during pregnancy, particularly during the first trimester, increase the risk for miscarriages, preterm birth and other problems, according to the Society for Maternal-Fetal Medicine.

Speaking alongside Kennedy, a vaccine skeptic, Trump stopped short of opposing all vaccines. But he said key immunizations should be delayed, or combination shots should be given separately — even though it has been proven that vaccines have no link to autism.

“Don’t let them pump your baby up with the largest pile of stuff you’ve ever seen in your life,” he said.

Trump also wildly overstated how such shots — some of which protect against four diseases — are given.

“I think it’s very bad. They’re pumping, it looks like they’re pumping into a horse,” Trump said. “You have a little child. A little fragile child. And you’ve got a vat of 80 different vaccines, I guess, 80 different blends, and they pump it in.”

What Does The Science Show?

Drexel University’s Lee and his colleagues examined the link between acetaminophen and neurodevelopmental disorders, including autism and attention-deficit/hyperactivity disorder, in a 20-year study that followed 2.5 million pregnant women and their children in Sweden. Their findings were published last year in the Journal of the American Medical Association.

“We found [in this study] a slight statistical increase in risk of autism and ADHD, but association is not causation,” said Lee, who holds a doctorate. “This is kind of an apples-to-oranges comparison because the [acetaminophen] users are so different in many ways.”

The “big elephant in the room” is genetics, he said. In a sibling analysis of children who were exposed to acetaminophen in the womb, Lee and his colleagues found no link.

Their paper suggested that mothers who are genetically predisposed toward autism or ADHD are more likely to have conditions that cause them to use acetaminophen for pain relief, but the same predispositions could be what increases the likelihood of a child having those conditions.

Lee and his colleagues weren’t the only researchers controlling for genetics in their studies. “Those studies are not supporting that a causal association exists between acetaminophen use and autism,” he said.

“The science hasn’t changed,” Lee continued. “The administration has done some things that raise eyebrows, at least as far as scientists are concerned, and they aren’t grounded in the best scientific evidence.”

Lee also dismissed Trump’s claim that autism isn’t found in Amish communities.

“That’s not necessarily the most credible claim. If there were any data to support that, well, what’s more likely to happen is that people who might be Amish are going to be less likely to seek medical care, which also would result in less chance of getting an autism diagnosis,” he said.

Lee does his research in Sweden, where autism rates are “quite high,” he said, explaining that differences in diagnosing and reporting of conditions like autism, not differences in genetics, are the most likely cause of varying prevalence rates across countries. While it’s easy to assume outside factors cause these differences, autism’s strong genetic component suggests that the true prevalence is probably similar worldwide, he said.

One conflicting paper that has gotten attention is a 2025 review of literature by researchers at Mount Sinai Medical Center.

“Our findings show that higher-quality studies are more likely to show a link between prenatal acetaminophen exposure and increased risks of autism and ADHD,” lead author Dr. Diddier Prada, an assistant Professor of Population Health Science and Policy, and Environmental Medicine and Climate Science, at the Icahn School of Medicine at Mount Sinai, said in a news release. “Given the widespread use of this medication, even a small increase in risk could have major public health implications.”

The study wasn’t based on new findings, but a quality-weighted review of old studies emphasizing those the researchers believe to be high quality and dismissing those they considered to be of lower quality, Lee said.

“And this is where scientists will disagree on what one person perceives to be a high quality and another person might not believe or agree with,” he said. “And so the conclusions that they reach in this paper are not necessarily what other scientists would agree on.

Lee added, “The study, in my opinion, is a fairly selective cherry-picked analysis of the evidence to date.”

What Did Tylenol Say?

Tylenol maker Kenvue disputed any link between the drug and autism and warned that if pregnant mothers don’t use Tylenol when in need, they could face a dangerous choice between suffering fevers or using riskier alternatives.

In a statement, the company said:

“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.

“Acetaminophen is the safest pain reliever option for pregnant women as needed throughout their entire pregnancy. Without it, women face dangerous choices: suffer through conditions like fever that are potentially harmful to both mom and baby, or use riskier alternatives.

“The facts are that over a decade of rigorous research, endorsed by leading medical professionals and global health regulators, confirms there is no credible evidence linking acetaminophen to autism. We stand with the many public health and medical professionals who have reviewed this science and agree. We will continue to explore all options to protect the health interests of American women and children.”

What Did The FDA Say?

In an open letter, the FDA took a more cautious approach than Trump, encouraging physicians to “consider minimizing the use of acetaminophen during pregnancy for routine low-grade fevers.”

“This consideration should also be balanced with the fact that acetaminophen is the safest over-the-counter alternative in pregnancy among all analgesics and antipyretics; aspirin and ibuprofen have well-documented adverse impacts on the fetus,” the letter read.

The agency made clear that a causal relationship between acetaminophen and autism has not been established in multiple studies, but also cited “contrary studies in the scientific literature.”

“The association is an ongoing area of scientific debate and clinicians should be aware of the issue in their clinical decision-making, especially given that most short-term fevers in pregnant women and young children do not require medication,” the FDA said.

What Should Pregnant Women Do?

Experts said pregnant women should continue to talk to their doctors and health providers about the risks of taking acetaminophen.

“Physicians remain the keystone in terms of being the best source of information because they are the ones who have to process the scientific information,” Lee said. “The average American out there shouldn't have to deal with that responsibility. So talk to your physician if you have questions. And ask questions, I think that’s the No. 1 recommendation.

“But the bottom line so far is that unless there's new evidence that's coming out to say otherwise, the expert clinical bodies out there do not have any, do not find any strong reason to believe that acetaminophen causes autism or ADHD,” he said.

The Associated Press contributed reporting.

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