A new study by researchers at Human Longevity, Inc. suggests that acetaminophen (Tylenol) may reduce the placenta’s ability to regulate hormone levels. The study found an association with acetaminophen use and lower levels of neurosteroids (hormones found in the brain).

“A 2017 study found that exposure is associated with male urogenital malformation and altered male brain masculinization, which controls gender-linked behavior in mice, such as the frequency of intercourse and aggression toward rival males.”

“A 2015 study found evidence that prenatal exposure to acetaminophen may reduce the ability of the male fetus to produce testosterone. Testosterone production was reduced in human fetal testicular tissue that had been transplanted into castrated mice given acetaminophen for a week.”