Robert F. Kennedy Jr. Makes Bizarre Connection Between Circumcision, Tylenol, and Autism

Robert F. Kennedy Jr. is doubling down on the Trump administration’s claim that taking Tylenol could cause autism, but with a twist: Along with his past suggestion that pregnant women taking acetaminophen are putting their unborn child at risk of the condition, Kennedy on Thursday claimed that boys who took the painkiller after being circumcised could somehow trigger autism.

During the meeting, Kennedy said that there are “two studies that show children who are circumcised early have double the rate of autism. It’s highly likely because they are given Tylenol.â€

Kennedy made the bizarre connection to circumcision at a White House Cabinet meeting on Thursday, alluding to published research in support of his claim. But those findings are disputed, and at least one of the studies Kennedy seemed to refer to did not look at Tylenol use in children who were circumcised in the first place.

Circumcision conjecture

Kennedy didn’t specifically cite the “two studies,†but a look at the literature suggests he may have been referencing—and somewhat conflating—the findings of two papers published in 2013 and 2015, respectively.

The 2013 paper looked at rates of autism, acetaminophen use among pregnant mothers and young infants, and circumcision across U.S. states as well as in eight different countries. The study found an association between circumcision and autism rates, and the association was strongest after 1995 in the country-level analysis. The authors argued that since acetaminophen was more widely used as a pain reliever after circumcision starting in the mid-1990s, that could explain this trend. However, the authors specifically cautioned that their findings “cannot provide strong evidence of causality.â€

The 2015 paper, meanwhile, looked at rates of reported autism and circumcision among boys born in Denmark between 1994 and 2003. This study that found boys circumcised before age five were twice as likely to be diagnosed with autism. The study authors speculated that the pain of circumcision might cause early life stress that could later lead to autism, but not that treatments for the pain, like Tylenol, might be linked to autism. Indeed, the study authors noted they weren’t able to examine how often children were given Tylenol after a circumcision, meaning they couldn’t have tested RFK Jr’s hypothesis even if they wanted to.

The 2015 study in particular received a lot of attention from other researchers upon publication, many of whom seemed to be thoroughly unimpressed.

In an editorial published by the Journal of the Royal Society of Medicine (which published the original 2015 paper), scientists not involved in the study argued that the investigation was littered with flaws. Among other things, they pointed out that many health conditions early in life can cause similar or greater levels of pain as circumcision, including urinary tract infections, which tend to be more common in uncircumcised boys. Other scientists at the time called the study’s claims “extremely speculative.†And in 2022, a follow-up systematic review failed to find any conclusive evidence of a causative link between circumcision and autism.

It’s also worth noting that circumcision rates in the U.S. have declined in recent years, even as autism rates have climbed during that same period.

Grasping for answers

Scientists and medical associations have soundly criticized the Trump administration’s attempts to link Tylenol and autism and to discourage women from taking the drug as unfounded in science and potentially dangerous for women. And while some studies have suggested a possible connection between acetaminophen and autism, the most comprehensive and largest studies on the topic haven’t found any link, and health agencies across the world have refused to endorse the theory. Ultimately, there is no evidence that taking acetaminophen—at any time in life—causes autism.

Kennedy, it seems, perhaps knows that the evidence for his claims is lacking. During the same meeting Thursday, after suggesting that pregnant women are irresponsible for taking Tylenol, Kennedy said that the evidence for a link between acetaminophen and autism is not so crystal clear as he and U.S. President Donald Trump’s recommendation that women avoid the drug at all costs made it seem. “It is not proof. We’re doing the studies to make the proof,†Kennedy said.