Science Says: Tylenol During Pregnancy Does Not Cause Autism
Another significant study has shown there is no link between acetaminophen, likely better known by its brand name Tylenol, and autism, attention-deficit/hyperactivity disorder (ADHD), or intellectual disability. The two-decade-long study conducted in Hong Kong reinforces that it remains safe to take Tylenol during pregnancy, as no correlation was found across trimesters, doses, or prescribed frequency.
These findings are consistent with similar studies conducted in Sweden in 2024 and in Japan in 2025.
The Study on Tylenol and Autism
Each study compared siblings born to the same mother such that only one sibling was exposed to acetaminophen during pregnancy. The most recent from Hong Kong sourced 708,020 examples across a 22-year period. Of those, 43% involved acetaminophen during pregnancy.
Sibling cohorts in which one was exposed to acetaminophen during pregnancy and the other not had two years’ and five years’ worth of records analyzed for any link to autism and ADHD diagnoses, respectively. No such link was found for either. The findings held at every dose, including standard 500 mg tablets.
Is Tylenol Safe During Pregnancy?
Tylenol is an antipyretic and analgesic agent that helps treat pain and fever, both of which occur frequently during pregnancy. The vast majority — seven out of 10 — of pregnancies are reported to involve moderately severe pain; fevers are common. The anatomical changes during pregnancy increase heart rate and cardiac output to support blood flow to the baby and can cause breathing difficulties due to a raised diaphragm (by about four to five centimeters).
Suffice to say, pregnancy can be painful. It’s worth knowing whether the most-preferred pain reliever among healthcare providers is safe to use.
The Whole Truth
In September 2025, days after federal officials suggested a possible link between acetaminophen and autism, the Food and Drug Administration (FDA) initiated the process for acetaminophen-based products to include a label that suggests a link between the drug and autism, ADHD, and other neurological disorders, despite a body of evidence that has not established a causal relationship.
Put simply, as the National Academy of Medicine states, correlation is not causation. If a child is born with a neurological disorder and the mother consumed acetaminophen during the pregnancy, the former is not necessarily caused by the latter.
Tylenol’s manufacturer, Kenvue, urged against the neurodevelopmental disorders warning label, stating “the overwhelming weight of the evidence contradicts the existence of any such risk.”
