The Largest Study of Tylenol and Autism Found No Link Once It Compared Siblings

The claim that acetaminophen (Tylenol) use in pregnancy is associated with a very increased risk of autism is mostly false. A 2024 JAMA study of 2,480,797 children found the small association in raw data vanished once siblings were compared (autism hazard ratio 0.98), meaning it reflected family confounding, not the drug. ACOG calls the claim irresponsible and notes untreated fever carries its own fetal risk. Elena rates it Mostly False.