(KRON) — Pregnant women who take acetaminophen are more likely to have a hyperactive child, according to a new study, CNN reports.

Researchers said expectant mothers exposed to the drug run a higher risk of having children with emotional or behavioral symptoms.

Acetaminophen is the active ingredient in Tylenol and other popular over-the-counter medications.

Users take it for everything from allergies, colds, the flu, and to sleep better.

The study said it is safe for pregnant women to use, but should be taken only when necessary to minimize risks.

The study published in Jama Pediatrics shows more than half of all pregnant women in the US and Europe use acetaminophen.

The study’s lead author does say acetaminophen is safe for pregnant women to use, but should be taken only when necessary to minimize risks.

The FDA has reviewed previous studies on prenatal use of the medication, finding “limitations” in the design of those studies.