Health Secretary Robert F. Kennedy Jr. is once again drawing criticism from medical experts — this time for suggesting a link between circumcision, Tylenol use, and autism. His comments, made during a Cabinet meeting on Thursday, have reignited a wave of scientific rebuttals emphasizing that no credible research supports the claim.
“There’s two studies that show children who are circumcised early have double the rate of autism. It’s highly likely because they are given Tylenol,” Kennedy said.
Kennedy did not identify the studies he was referring to, but experts say two older studies — one published in 2013 and another in 2015 — may be what he had in mind. Both papers examined possible statistical associations between circumcision and autism but stopped far short of proving causation.
Correlation Is Not Causation
The 2013 study compared circumcision rates in several countries with national autism rates. The authors themselves cautioned that their analysis might reflect correlation, not cause and effect, and noted potential sources of error and bias.
“Circumcision practices are tied to culture and religion, which also affect autism diagnoses and health care use,” explained Dr. Céline Gounder, CBS News medical contributor and editor-at-large for public health at KFF Health News. “Confounding is at the root of much of what RFK Jr. cites and claims.”
Confounding happens when a third factor distorts the apparent relationship between two variables. Gounder compared the problem to a classic example from epidemiology: early studies once linked coffee drinking to heart disease, but it turned out the real culprit was smoking — coffee drinkers were simply more likely to smoke. Similarly, ice cream sales rise in the summer, as do drowning incidents, but one doesn’t cause the other; both are linked to warmer weather and more swimming.
What the Studies Actually Showed
The 2015 Danish study found that boys circumcised before age five appeared to have a higher risk of autism diagnosis — but the association disappeared after that age.
“If circumcision truly caused autism, that association should continue even after age five,” said Gounder. “What’s more likely is that children receiving early circumcision have greater contact with the health care system and parents with higher education and income — all factors linked to earlier autism diagnosis.”
In other words, the apparent “link” may simply reflect differences in access to medical care, not an underlying biological connection.
Experts: No Scientific Evidence for a Causal Link
Pediatricians and researchers have strongly pushed back on Kennedy’s assertions.
“There are absolutely no studies establishing any causality,” said Dr. Steven Abelowitz, founder and medical director of Ocean Pediatrics. “While some observational studies suggest possibly an association, there are no credible studies showing causality — and every credible medical source agrees there’s no causal relationship between Tylenol, circumcision, or vaccines and autism.”
Acetaminophen, the active ingredient in Tylenol, is often used to reduce pain and fever. However, the claim that infants are given Tylenol after circumcision is generally inaccurate, according to pediatricians.
Timing Doesn’t Add Up
“Children younger than 12 weeks should not be given acetaminophen unless specifically instructed by a pediatrician,” according to the American Academy of Pediatrics. Most circumcisions, meanwhile, occur within the first 48 hours after birth — far earlier than the age when Tylenol would typically be considered safe.
“We almost never, ever use Tylenol after circumcision,” Abelowitz said, noting he has performed around 10,000 circumcisions in his 30-year career. “The procedure is typically done with local anesthetic, and newborns recover quickly without needing pain medication.”
Understanding Circumcision Trends
Circumcision rates in the United States have been slowly declining over the past decade. A 2025 report from Johns Hopkins Medicine found the national prevalence dropped from 54.1% in 2012 to 49.3% in 2022. For many families, circumcision is a deeply personal decision shaped by religion, culture, or tradition — not public health policy.
Despite ongoing debate around circumcision’s benefits and risks, no mainstream scientific or medical organization has ever connected the procedure to autism or any neurological disorder.
Echoes of an Old Debate
Kennedy’s remarks echo a familiar pattern in public health communication — invoking weak correlations to suggest unproven causes of complex disorders. Autism spectrum disorder (ASD) is believed to arise from a combination of genetic and environmental factors, but scientists have not identified any single exposure that “causes” autism.
Statements linking autism to everyday medications, such as acetaminophen, risk confusing the public and undermining trust in safe, commonly used treatments.
“Suggestions that acetaminophen use in pregnancy causes autism are not only highly concerning to clinicians but also irresponsible,” said Dr. Steven J. Fleischman, president of the American College of Obstetricians and Gynecologists. “These claims send harmful and confusing messages to pregnant patients who may need this beneficial medicine.”
The U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) have both affirmed that acetaminophen is safe when used as directed, including during pregnancy.
Pushback from Autism Advocates
Kennedy’s statements also drew international criticism. In the United Kingdom, the National Autistic Society called his comments “dangerous anti-science,” warning they could further stigmatize families living with autism.
“This is not based on any form of rigorous, robust research and could put lives at risk,” said Mel Merritt, the group’s head of policy and campaigns.
Public health experts worry that such claims can lead parents to distrust vaccines, medications, and even medical professionals — potentially delaying necessary care for children.
The Takeaway
Health misinformation thrives on emotional issues like childhood health and parental fear. But experts stress that strong, well-designed scientific studies consistently show no causal connection between autism and circumcision, Tylenol, or vaccines.
“There’s no evidence — none — that circumcision or Tylenol causes autism,” Gounder said. “It’s important that parents hear that message clearly and rely on science, not speculation.”
As the discussion around Kennedy’s comments continues, medical professionals are urging the public to treat such statements with caution — and to always look to evidence-based sources for health guidance.
I think Mr. K has no idea about science research. I do t remember giving my son or grandchildren giving them any Tylenol they came out of hospital circumcised, and if so , for sure only gave them first day, dont think a low dose would cause autism.
Kennedy grabbing straws ,I think he’s psycho my self .but circumcision is not the cause of adhd my 10 yr old who has autism spectrum was circumcised at 1half yr old n his 4 yr old brother at the time was also circumcised. I’ve had custody of them for 10 yrs now .Kennedy needs stop inventing dumb stuff .the 10 yr old ,mother had taken all kinds of drugs including Tylenol when she was pregnant but she was a drug addict too.n the oldest who now 14 is allergic to Tylenol n both have adhd
We need a Secretary of Health and Human Services who is more qualified than Senator Kennedy.