St. Johns Wort comes from a flowering plant called Hypericum perforatum. People take standardized extracts with meals for emotional well-being. The herb can alter how the body processes a wide set of drugs, sometimes making them far less reliable.
Birth control pills, antidepressants, blood thinners like warfarin, and certain heart medications are all affected. Do not take St. Johns Wort during pregnancy or while breastfeeding. Strong drug interactions mean you should always check with a health professional before starting.