The Topline
- U.S. President Trump publicly warned at a press conference on Monday that pregnant women should avoid taking Tylenol – or acetaminophen – claiming a link between its use in pregnancy and autism.
- The White House released a fact sheet arguing that “mounting evidence” shows an association between acetaminophen use in pregnancy and autism
The science is very clear
There’s no credible evidence that acetaminophen – commonly sold as Tylenol – causes autism.
Yes, the White House cited research from several respectable institutions, including Harvard, Johns Hopkins University, and Mount Sinai, which found small associations between prenatal acetaminophen use and later neurodevelopmental diagnoses.
However, the strongest and best-controlled research so far has found the link is tenuous at best. In 2024, Swedish researchers, studying a 2.48-million-child Swedish cohort using sibling-comparison methods, found that these associations disappear after researchers account for family genetics and underlying health factors of the mother, like fever and infection – which are known risk factors to adverse neurodevelopmental outcomes.
They are also the very reason why pregnant women take acetaminophen in the first place.
As a result, the study found no increased risk of autism, ADHD, or intellectual disability with prenatal acetaminophen use. Other major medical bodies have echoed these findings in their own research – the American College of Obstetricians and Gynecologists, for example, found that current evidence does not support a causal link between acetaminophen and neurodevelopmental disorders, and recommends its use for pain relief and fever reduction during pregnancy.
The World Health Organization , the European Medicines Agency , the UK’s Medicines and Healthcare Regulatory Agency and the American Academy of Pediatrics have also all found no causal link between acetaminophen and autism, and claim that it’s safe during pregnancy when used as directed.
So what?
The latest science indicates that it’s safe to use and won’t cause any adverse effects later in life. Pregnant women can use Tylenol to treat fever and pain when needed. It’s best to use the lowest effective dose for the shortest possible time, and consult with their doctor if they need frequent or high-dose use.
Those pesky associations are worth keeping in mind
The root causes of autism aren’t fully understood right now. In the absence of a clear, single cause, some advocacy groups – including the Children’s Health Defense, which U.S. Secretary of Health and Human Services Robert F. Kennedy Jr. founded, and where he served as chairman and chief litigation counsel until 2023 – have leaned hard into potential scapegoats. First there were vaccines, now there is Tylenol.
And yes, there is a body of research – including several studies cited by the White House – that have raised questions about acetaminophen and long-term neurodevelopmental outcomes. At least two studies analyzing blood and umbilical samples of infants associated higher acetaminophen exposure with greater odds of developmental diagnoses.
That research shows that acetaminophen may interfere with how cells handle stress and repair themselves, while possibly influencing chemical signals that guide growth and development, so some researchers have hypotheses about how it might influence brain development.
But – and this is a very large but – it’s important to note that these studies can’t prove cause and effect, they can only provide the association, which evaporates once researchers control for family or genetics, as detailed on our purple side .
Credible research indicates that pregnant women can use Tylenol to treat fever and pain, and it’s best to use the lowest effective dose for the shortest possible time. If they don’t stick to that suggested dose and time, there are some pregnancy-related concerns – but they aren’t about autism. Prolonged use can increase exposure in the fetus, causing potential liver damage, without adding any benefit, which is why doctors recommend minimizing it.
So what?
The White House is scapegoating Tylenol for political capital. Trump and, especially, RFK Jr. are presenting themselves as warriors fighting Big Pharma in order to galvanize a not-insignificant number of the population who are confused, frightened, or let down by medicine’s lack of clarity on this issue – even if the science isn’t there to back up their claims.
