On April 16, 2025, about two months after being sworn in as Secretary of Health and Human Services, RFK Jr. said that autism, “is a preventable disease. We know it’s an environmental exposure.” Then he made a sensational promise. “By September,” he said, “we will know what has caused the autism epidemic and we’ll be able to eliminate those exposures.” President Trump, claimed Kennedy Jr., will be the man who will eliminate autism from the United States.
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As promised, on September 22, 2025, President Donald Trump stepped to the microphone before a packed press corps. Standing behind him were Dr. Jay Bhattacharya, the Director of the National Institutes of Health (NIH), Dr. Marty Makary, the Commissioner of the FDA, Dr. Mehmet Oz, Director of the Center for Medicare and Medicaid Services, and Robert F. Kennedy Jr. Everyone assumed that President Trump would indict yet another vaccine or vaccine component as a cause of autism. But they were wrong.
“Hello everyone,” Trump began. “I’ve been waiting for this meeting for 20 years.” Then, like a game show host, Trump made The Big Reveal. “Tylenol during pregnancy can be associated with a very increased risk of autism,” he said. “So, taking Tylenol is not good.” Mothers, according to Trump, needed “to tough it out” if they had fever. Trump then turned the podium over to RFK Jr, who said, “Today, the FDA will issue a physician’s notice about the risk of acetaminophen (the generic name for Tylenol) during pregnancy and begin the process to initiate a safety label change.”
And there it was. Tylenol caused autism. This was not a trivial recommendation. Tylenol is one of the most widely taken drugs during pregnancy, used by roughly half of all pregnant women worldwide. But now, according to RFK Jr. and President Trump, to eliminate autism, all we needed to do was to stop taking Tylenol during pregnancy. All women needed to do was “tough it out.”
Unfortunately, as had been true for all of RFK Jr.’s other bogus claims about the causes of autism, this one didn’t make sense.
RFK Jr. talks endlessly about restoring trust in public health while at the same time promoting one false claim after another. Always without apology, and always putting us at greater risk.
First, the timeline didn’t add up. Tylenol entered the United States market in 1955. With increased use, a rise in autism should have occurred in the 1960s and 1970s, not in the 1990s. The rise in the incidence of autism in the 1990s was caused in large part by a broadening of the definition of the disorder and increased awareness, not Tylenol use.
Second, RFK Jr. had ignored two critical studies. One study was performed by a group of Swedish investigators who followed every child born in Sweden between 1995 and 2019 — 2.5 million children in all. The study evaluated 186,000 children exposed to Tylenol during pregnancy and compared them with their siblings who weren’t exposed. This was the single best and largest study ever performed on the subject. By comparing children exposed to Tylenol during pregnancy with siblings who had not been exposed to the drug, the researchers controlled for maternal health, socioeconomic background, and genetics. Same parents, same households, same genes.
The authors concluded, “Acetaminophen use during pregnancy was not associated with children’s risk of autism.” Another study of 200,000 children in Japan, which also included sibling controls, found no link between acetaminophen use and autism.
Recently, on January 16, 2026, a study was published in the journal, Lancet, that put the final nail in the Tylenol-causes-autism coffin. Researchers evaluated 17 studies that had used sibling controls finding that Tylenol use during pregnancy did not increase the risk of autism spectrum disorder, attention deficit-hyperactivity disorder or intellectual disabilities.
Case closed.
So, where’s the follow-up press conference where President Trump reassures the public that he and Secretary Kennedy were wrong about Tylenol? The one where they say that they were wrong to blame mothers for their children’s autism. RFK Jr. talks endlessly about restoring trust in public health while at the same time promoting one false claim after another. Always without apology, and always putting us at greater risk.
Paul A. Offit, MD, is director of the Vaccine Education Center and professor of pediatrics in the Division of Infectious Diseases at Children’s Hospital of Philadelphia. This piece originally ran on his Substack, Beyond the Noise!
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