Men's Health October 13, 2025 0 Comments

RFK Jr.’s Shocking Autism Claim on Circumcision: What the Research Really Uncovers—You Won’t Believe the Truth!

So, Robert F. Kennedy Jr. has officially shifted gears in his endless quest for autism scapegoats. If vaccines were last season’s culprits, this fall’s hot topics are now Tylenol and circumcision. Yes, you read that right—Tylenol and circumcision. During a recent Cabinet meeting, Kennedy—who, mind you, isn’t a medical doctor or autism researcher—claimed boys who get circumcised are “twice as likely” to be diagnosed with autism, blaming it all on the Tylenol they supposedly get afterward. It’s the kind of headline that makes you blink twice and wonder—are we really still circling the block with these myths? Spoiler alert: the science says nope. Let’s cut through the noise and get to the facts—because truth matters, especially when misinformation could cost more than just credibility. LEARN MORE

HEALTH SECRETARY ROBERT F. Kennedy Jr.’s previous go-to scapegoat for autism was vaccines. Now, it’s Tylenol and circumcision. Yes, really.

In a Cabinet meeting on October 9th, Kennedy—who is neither a medical doctor nor an autism researcher—reignited a controversial, long-debunked claim that boys who undergo circumcision are “twice as likely” to be later diagnosed with autism as those with intact penises. He went on to say it’s “likely because they were given Tylenol” after the procedure.

These statements follow on the heels of both Kennedy and President Donald Trump warning pregnant people to “fight like hell” not to take Tylenol, during a press conference in late September.

“There is zero evidence to support these claims,” Gabrielle Dauer, MD, a double board-certified pediatrician and child development specialist, tells Men’s Health. “There is no study showing that circumcision or Tylenol has a causative relationship to autism.”

To get a sense of how these myths took hold—plus what the research actually says—we chatted with a number of medical experts and psychologists who specialize in autism.

A Familiar Pattern of False Claims

For anyone who’s been keeping up with Kennedy, this latest “theory” likely won’t come as a surprise. Kennedy has a well-documented history of “citing” studies to make his theories sound more legit.

His latest iteration of autism misinformation is no exception.

“There are many, many confirmation studies,” Kennedy said at the hearing. “There are two studies that show how children who are circumcised early have double the rate of autism. It is very likely because of Tylenol.”

The thing is, there aren’t any so-called “confirmation” studies. There are just two small, old papers—and neither actually shows what Kennedy suggests they do.

Why The Old Research Doesn’t Hold Up

The first of the two studies Kennedy was likely referring to is a 2013 study published in Environmental Health, which noted that in some countries, rising use of acetaminophen (Tylenol) paralleled reported increases in autism diagnoses between 1984 and 2005.

The authors themselves emphasized that their findings were correlational, not causal, and called for more rigorous research. Meanwhile, Sarah Oreck, MD, MS, a reproductive psychiatrist and therapist, CEO of Mavida Health, says that using this study to claim that Tylenol causes autism “is like noticing that cities with more ice-cream sales also have more drownings and assuming ice cream causes drowning, when both are really linked to hot weather.”

The second, a small study published in the Journal of the Royal Society of Medicine, examined a national register-based cohort in Denmark, comprising 342,877 boys born between 1994 and 2003. Of the roughly 5,000 autism cases identified, the researchers observed that circumcised boys were slightly overrepresented compared to those who were not. But again, correlation does not equal causation.

The Danish study also didn’t account for key factors like healthcare access, diagnostic practices, or cultural differences.

“Circumcision is a surgical procedure that involves the removal of the foreskin of the penis, and is most often performed in the hospital,” explains George F. Ellis, MD, a physician and board-certified urologist.

With that, one hypothesis is that families who opt to circumcise their child may have greater interaction with the healthcare system early on in that child’s life. So, potential developmental differences (like autism) could simply get diagnosed sooner in boys who are circumcised. In other words, any apparent link may reflect diagnostic bias rather than biology.

“In the decade-plus since each was published, researchers have heavily criticized both of these studies,” says Dr. Ellis. Neither measured Tylenol intake directly nor offered any hypotheses about how they might be linked. And both relied on registry or population-level data that, by definition, cannot isolate cause and effect.

Further, follow-up research has not found credible evidence linking circumcision—or the use of Tylenol after the procedure—to higher rates of autism. (More on that ahead).

Again: Tylenol Does Not Cause Autism

Current research about autism and its causes remains complex and evolving. What science has shown, however, is that autism isn’t the result of a single factor or event. Instead, “autism emerges from a unique combination of genetic factors, environmental triggers, and complex developmental influences that begin long before birth,” says Dr. Oreck.

A 2024 study published in JAMA saw no connection between parental Tylenol use during pregnancy and autism. Researchers looked at the health and birth records of more than 2.5 million children and found no causal association between prenatal acetaminophen (Tylenol) intake and offspring autism.

The researchers even compared autism risk between siblings—one was exposed to Tylenol during pregnancy and one was not—and reported no connection at all. The authors concluded that studies (like the two Kennedy was likely referring to) were potentially skewed by familial or environmental confounding factors, not by the medication itself.

Meanwhile, the American Academy of Pediatrics reports that when administered as recommended, there is no connection between children taking Tylenol in early life and a later autism diagnosis.

Circumcision Doesn’t Cause Autism, Either

“When performed by a trained professional, circumcision is considered very safe,” says Justin Houman, MD, a board-certified urologist who specializes in hormone health, sexual health, and fertility, and the Senior Medical Advisor at sexual wellness platform Cake.

Sure, circumcision can cause some temporary discomfort. As Dr. Ellis says, “it may not be a major type of surgery, but it is a surgical procedure with inherent risks, such as mild bleeding, swelling, or infection.” What having a small piece of skin removed can’t do, however, is put you on the spectrum.

“There is no credible scientific evidence that circumcision causes autism,” says Dr. Houman. In fact, researchers have heavily criticized that idea.

Circumcision may be performed for many different reasons, including religious, cultural, personal, or medical, notes Dr. Ellis. (Someone with phimosis, a condition marked by the foreskin being too tight to retract, may opt to have it removed.)

Most commonly, however, circumcision is part of a cultural or religious tradition. “In Judaism and Islam, for example, circumcision is a longstanding rite of passage. For others, it’s based on family history or hygiene preference,” says Dr. Houman. “It’s important to understand this cultural context because attacking circumcision when there is no evidence unfairly targets entire groups where circumcision is a normal part of life and can lead to xenophobic or culturally insensitive rhetoric,” he adds.

Ultimately, circumcision is an optional procedure. But as Dr. Houman says, “Parents should feel empowered to make their decision based on facts, not fears.”

The Harm Is RFK’s False Claims—Not Tylenol or Circumcision

Ultimately, this type of misinformation can be dangerous to the health and well-being of us all. For example, pregnant people frightened away from Tylenol may forgo treatment for fever, which does have proven risks to fetal development.

“All the recent claims about autism diagnosis do is falsely point fingers, and increase stigma against people living with autism,” says Dr. Dauer. “The reality is, many people fall on the autism spectrum, and so many more incredible leaders, thinkers, scientists, and physicians are autistic themselves and have contributed grandly to our society.”

The same goes for those who are circumcised!

The bottom line: Kennedy’s circumcision-autism claims might make headlines or turbo-charge conspiracies, but they don’t actually make any sense. The science is clear: Neither Tylenol nor circumcision causes autism.

Gabrielle Kassel (she/her) is a sex and fitness journalist committed to helping people feel the best they can in their bodies. In addition to Men’s Health, her work has appeared in publications such as Shape, Cosmopolitan, Well+Good, Health, Self, Women’s Health, Greatist, and more! In her free time, Gabrielle can be found coaching CrossFit, reviewing pleasure products, hiking with her border collie, or recording episodes of the podcast she co-hosts called Bad In Bed. Follow her on Instagram @Gabriellekassel.