On Sept. 22, 2025, President Donald Trump announced during a press conference that Tylenol (acetaminophen) may be linked to autism, prompting the Food and Drug Administration (FDA) to begin updating warning labels for pregnant women. His statement immediately sparked widespread public reaction — from serious concerns to viral Internet memes — and re-ignited the debate about whether scientific evidence supports a connection between Tylenol and autism spectrum disorder.

The discussion gained momentum after Andrea Baccarelli, Dean of Faculty at the Harvard T.H. Chan School of Public Health and the senior author for a study published Aug. 14, 2025 about the association between acetaminophen and neurodevelopment disorders spoke about his findings with Health and Human Services Secretary Robert F. Kennedy Jr. Baccarelli research found a link between the two, but noted, “That association is strongest when acetaminophen is taken for four weeks or longer,” cautioning about heavy or prolonged use of the drug.

However, since the announcement, other researchers, medical experts, and major scientific publications have emphasized that there is not a link between acetaminophen and neurodevelopment disorders.

Springer Nature, an international scientific journal, explained, “Many researchers who study autism caution that there are insufficient data to link it with paracetamol (aka acetaminophen), and focusing on this is merely just a distraction.”

One scientist interviewed in Springer Nature was Viktor Ahlqvist, an epidemiologist at the Karolinska Institute in Stockholm. He and a team of other researchers and scientists examined whether there is a link between the two.

The team compared siblings born to the same mother, where one sibling was exposed to paracetamol and one sibling was not. Since siblings share half a genome, have a similar upbringing and maternal health, the differences they would notice in autism would be due to the drug itself. In using this method, the researchers found no link between paracetamol and autism. Another study in Japan that examined over 200,000 children using the sibling comparison method also found no association between the two. 

The spokesperson for Tylenol’s manufacturer released a statement, saying, “We believe independent, sound science clearly shows that taking acetaminophen does not cause autism.”

On the same day of the press conference, the FDA published a news release on its website supporting the idea that the use of acetaminophen during pregnancy causes autism. The two studies listed were the Nurses Health Study II and Boston Birth Cohort. 

In the Nurses Health Study II, researchers examined whether taking acetaminophen would increase the risk of a child having ADHD. They studied about 8,800 children whose mothers were a part of this study. The results showed only 8 percent of the children had ADHD with the use of acetaminophen before, during, and after pregnancy. 

In the second study, Boston Birth Cohort, 996 mother-infant dyads were studied by testing their umbilical cord blood to measure how much acetaminophen the baby was exposed to before birth. The researchers found that the higher the levels of acetaminophen the more likely they were to be diagnosed with ADHD, autism, or both. 

The FDA release also stated, “Some studies have described that the risk may be most pronounced when acetaminophen is taken chronically throughout pregnancy.”

What is the harm in telling pregnant people to not take certain medications? And what’s to blame for the rise in autism? 

Helen Tager-Flusberg, a psychologist who researches autism at Boston University, says news releases such as these could be harmful because they increase “…fear in pregnant women at a time when they truly don’t need to, and it is absolutely not grounded in the scientific findings.” 

Ahlqvist echoed this statement, saying, “We risk placing blame on mothers and causing more stress, self-blame and stigma, despite having no evidence to support such claims.”

Researchers explain that most of the increase in diagnosed autism is due to the change in diagnostic criteria, which has changed exponentially due to how parents and adults now pursue diagnosis to help with education and healthcare. The criteria also led to a change in how clinical professionals interpret and apply it.

Most of the scientific community agrees there is no official evidence to back up the claims that acetaminophen causes autism, and there is only evidence that there could be an increased risk if taken constantly. This is similar to what many other medications can do if taken too often.

When students on Park University’s campus were asked about their thoughts and opinions on the Tylenol causing autism announcement, many agreed it seems to be a non-factual statement.

One student, who asked to remain anonymous, explained that this could make sense if it is taken too much, but does not particularly support the whole idea of Tylenol being the main cause of the increase in autism. Another who also asked to remain anonymous expressed that this information could make sense, but doubts it is true, noting that it is hard to decide what is or is not true coming out of the government right now.

Despite current statements from the government, the scientific community noted that Tylenol (acetaminophen) should not be taken constantly — just like many other over-the-counter drugs and prescriptions — because it can cause long-term effects, whether you are pregnant or not.