US President Donald Trump and his Secretary of Health, Robert F. Kennedy Jr., promoted another unfounded theory linking autism to circumcision and the use of Tylenol (or paracetamol), a medication used to calm the pain after the procedure.

“Don't take Tylenol if you're pregnant. And when the baby is born, don't give it Tylenol,” Trump stated during a cabinet meeting.

“There are two studies that show that boys circumcised early have double the rate of autism cases (…). It's most likely because they're given Tylenol,” Kennedy Jr. added.

Lack of knowledge about anatomy and pregnancy

Despite their statements, both acknowledged that they still do not have conclusive evidence: “We are doing the studies to prove it,” added the Secretary of Health, who in the meeting showed ignorance of female anatomy.

Kennedy Jr. said he was watching a video on TikTok where a pregnant woman was “devouring Tylenol” with “a baby in her placenta.”

A fetus develops in the uterus, not in the placenta. The placenta is a temporary organ that forms in the uterus during pregnancy and delivers oxygen, nutrients, and hormones to the developing fetus.

“None of this makes sense,”

Medical and scientific experts ridiculed Trump and Kennedy Jr.'s claims, pointing out that the main study cited by proponents of the theory is riddled with errors.

“None of this makes sense,” said Professor Helen Tager-Flusberg, an autism expert at Boston University.

“None of the studies have shown that giving Tylenol to babies is linked to an increased risk of autism,” she added.

There is no proven causal link.

Medical associations recommend moderate use of pain relievers with acetaminophen, the active ingredient in Tylenol, during pregnancy. Although some studies have suggested a possible association between acetaminophen and autism, No causal link has been proven.

In fact, the most rigorous analysis to date,published last year in the journal JAMA, found no connection.

Circumcision and a “flawed” study

Kennedy Jr. also suggested that circumcised boys had twice the rate of autism, likely because of the use of Tylenol after the procedure.

The assumption is based on a 2015 study by Danish researchers that was heavily criticized for its methodology at the time.

David Mandell, a psychiatrist at the Perelman School of Medicine at the University of Pennsylvania, explains that the study was “flawed” and based on a very small sample of Muslim boys circumcised in hospitals.

Mandell argues that they were likely “medically compromised in other ways,” which could explain the higher rates of disorders behavioral neurodevelopment.

“A more recent review of studies in this area finds no association between circumcision and adverse psychological effects,” he adds.

Kennedy Jr. and his penchant for “pseudoscience”

The US health secretary, a former environmental activist and lawyer, has previously been widely criticized for his penchant for “pseudoscience” and for spreading misinformation about vaccines for decades.

Since taking office, Kennedy Jr. has focused his efforts on researching the causes of autism while cutting funding for other areas of research.

He even hired conspiracy theorist David Geier, who has been disciplined for practicing medicine without a license and for giving unapproved drugs to autistic children, to investigate links between vaccines and autism, a connection refuted by dozens of studies and the World Health Organization (WHO).