Some Drug Interactions With St. John's Wort

Benzodiazepines

St. John’s wort may reduce the effectiveness of these medications in reducing anxiety and may increase the risk of side effects such as drowsiness.

St. John’s wort may reduce blood levels of factor Xa inhibitors.

Iron

St. John’s wort may reduce iron absorption.

Monoamine oxidase inhibitors (MAOIs)

St. John’s wort may intensify the effects of MAOIs, possibly causing very high blood pressure that requires emergency treatment.

Nonnucleoside reverse transcriptase inhibitors

St. John’s wort increases the metabolism of these medications, reducing their effectiveness.

Oral contraceptives

St. John’s wort increases the metabolism of oral contraceptives, reducing their effectiveness.

When taken with these medications, St. John’s wort may increase the risk of sun sensitivity.

St. John’s wort may reduce blood levels of protease inhibitors, making them less effective.

St. John’s wort may intensify the effects of these medications.

Tricyclic antidepressants

St. John’s wort may decrease the effects of these medications.