On October 9, 2025, the U.S. medical community was rocked by comments from Health and Human Services Secretary Robert F. Kennedy Jr., who claimed during a Cabinet meeting that early circumcision in boys could double the risk of autism, a link he attributed to the use of Tylenol (acetaminophen) after the procedure. "There’s two studies which show children who are circumcised early have double the rate of autism. It’s highly likely because they were given Tylenol," Kennedy stated, according to CBS News and other outlets. The remarks swiftly ignited debate and concern, not just among parents and caregivers, but also within the scientific and medical establishment.
Kennedy’s assertions came mere weeks after President Trump also cast doubt on Tylenol’s safety for pregnant women, suggesting that acetaminophen use might increase the risk of autism in their children. Trump, echoing Kennedy’s sentiment, declared, "There’s a tremendous amount of proof or evidence, I would say as a non-doctor," though he did not provide specific studies to back his claim, as reported by The New York Post.
But do these claims hold up under scientific scrutiny? Medical experts and leading health organizations have been quick to push back, warning that such statements lack solid evidence and risk spreading unnecessary anxiety among expectant parents and caregivers. Dr. Robert Melillo, a neuroscientist with more than three decades of experience working with autistic children and adults, told The New York Post, "I think what they are doing is good intentionally. But the messaging is terrible." He emphasized, "You can’t speak to causation if you don’t understand what the actual problem is, and that’s part of the confusion."
Kennedy did not cite the studies he referenced, but experts and journalists have pointed to two likely candidates: a 2013 study comparing national circumcision and autism rates in eight countries, and a 2015 Danish paper that tracked more than 340,000 boys. The Danish study found a slightly higher rate of autism by age 10 among circumcised boys, but it notably lacked any data on what medications, if any, were used post-procedure. The 2013 study, meanwhile, found only a weak correlation between circumcision and autism rates, with the authors themselves acknowledging that their findings could be influenced by cultural, religious, and healthcare access factors—classic confounding variables.
Dr. Céline Gounder, a CBS News medical contributor and editor-at-large for public health at KFF Health News, explained, "Circumcision practices are also tied to culture and religion, which also affect autism diagnoses and healthcare use." She pointed out that confounding—when a third variable distorts the relationship between an exposure and an outcome—is "at the root of much of what RFK Jr. cites and claims." Gounder used the example of early studies that linked coffee drinking with heart disease, only to later discover that smoking, not coffee, was the real culprit.
Further muddying the waters, the 2015 Danish study found that the increased risk of autism was only present in boys under age five and disappeared entirely after that age. Gounder noted, "If circumcision truly caused autism, that association should continue even after age 5. They're likely picking up on the fact that kids undergoing circumcision in the healthcare system have greater contact with the healthcare system and have parents with higher levels of education and income—all of which are associated with being diagnosed with autism at a younger age than other kids. That association may disappear once kids start school, when teachers and counselors pick up on the symptoms."
On the subject of Tylenol, Dr. Sarah Oreck, a reproductive psychiatrist and founder of Mavida Health, told The Post, "There is no clear or conclusive evidence that the use of Tylenol (acetaminophen) during pregnancy causes autism." She and other experts pointed out that acetaminophen has been used safely for decades to treat pain and fever and remains one of the safest options for pregnant women and young children when used as directed. Oreck added, "The research couldn’t separate the medication from the illness being treated. It’s like blaming umbrellas for rain—just because they show up together."
Dr. Steven Abelowitz, founder and medical director of Ocean Pediatrics, was even more direct, telling CBS News, "There is absolutely no studies establishing any causality. While some observational studies suggest possibly an association, there’s no studies (showing causality)—and the conclusion by any credible medical resource is agreeing that there’s no causal relationship between Tylenol, circumcisions or vaccines to autism." Abelowitz also noted that, in his 30 years of practice performing about 10,000 circumcisions, "We almost never, ever use Tylenol after circumcision." Most circumcisions in the U.S. occur within the first week after birth, often within the first 48 hours, and typically involve only a local anesthetic, according to the Cleveland Clinic and the American Academy of Pediatrics (AAP).
The AAP went so far as to issue a "Fact Checked" statement, reiterating the safety of Tylenol use in pregnancy and infancy. The organization criticized the administration for spreading what it called potentially life-threatening misinformation: "Misleading claims that the medicine is not safe and is linked to increased rates of autism send a confusing, dangerous message to parents and expectant parents and does a disservice to autistic individuals."
International reaction was swift as well. The United Kingdom’s National Autistic Society condemned Kennedy’s remarks, with Mel Merritt, the group’s head of policy and campaigns, stating, "More dangerous anti-science from the US Health Secretary Robert F Kennedy, now linking autism with circumcision. This is not based on any form of rigorous, robust research and could put lives at risk."
Even Tylenol’s manufacturer, Kenvue, weighed in, telling CBS News, "Independent, sound science clearly shows that taking acetaminophen does not cause autism." The American College of Obstetricians and Gynecologists also reaffirmed the medication’s safety, with President Dr. Steven J. Fleischman stating, "Suggestions that acetaminophen use in pregnancy causes autism are not only highly concerning to clinicians but also irresponsible when considering the harmful and confusing message they send to pregnant patients, including those who may need to rely on this beneficial medicine during pregnancy."
With autism currently affecting 1 in 31 children in the U.S.—a rate that continues to rise—parents are understandably eager for answers. But as Dr. Melillo pointed out, "To really understand causation, you have to first explain what autism is and what is actually happening in the brain, and nobody is doing that at any level." He and others caution that focusing on weakly supported theories distracts from legitimate research and support for those affected by autism.
While Kennedy’s comments have sparked fresh debate, the overwhelming consensus among medical experts and organizations remains clear: there is no credible scientific evidence that circumcision or Tylenol use causes autism. Instead, experts urge parents to consult healthcare professionals and rely on established science when making decisions about their children’s health.
