FACT OR FICTION? IS THERE A LINK BETWEEN CIRCUMCISION AND AUTISM?

During a House Cabinet meeting on October 9th, 2025, the Health & Human Resources Secretary, Robert F. Kennedy, Jr. claimed that there may be a link between circumcision of male babies and young children, and autism. His claim suggested that male babies were twice as likely as uncircumcised boys to be diagnosed with autism, claiming the link “is highly likely because they were given Tylenol,” and he cited two studies in support of that finding.

Although not specific about which studies he may have been referencing, there is a Danish study by Frisch, et al, of a group of boys between 1994 and 2003 which found that, among that group, boys who were circumcised were 46% more likely to be diagnosed with autism spectrum disorder by age 10. However, being 46% more likely is not the same as being twice as likely. Perhaps he was singling out the study’s finding that boys under the age of 5 were twice as likely to receive an autism diagnosis.

Among the limitations of that study is that they had no data on whether any of the circumcised boys received Tyenol for pain. The authors also acknowledged that the study had several other significant limitations.

In countries, such as Israel, where ritual circumcision is nearly universal, the prevalence of autism spectrum disorder is about 1 in 88, according to the Israeli Ministry of Health. In the U.S. where circumcision is far less common, the rate is 1 in 36…according to the CDC.

When Kennedy linked the two studies he suggested the link is “likely because the babies were given Tylenol.” That is, at best, incoherent speculation. There is no definitive evidence to prove that circumcision, with or without the use of Tylenol, has any real link to autism.

When public health officials use their platform to promote pet theories rather than proven science, it is, at best, misleading to the public or possibly worse.