St. John's wort can interfere with oral contraceptives
July 2003
There's now more evidence that St. John's wort can interfere with oral contraceptives...and lead to unintended pregnancies.
St. John's wort increases the metabolism of ethinyl estradiol...and seems to reduce the effectiveness of OCs.
Some women have breakthrough bleeding when taking St. John's wort and OCs together.
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