The traditional medicinal herb St. John's Wort also seems to make COCPs not work as well. This is because of the way St. John's Wort affects the liver.
ð ə WORD_BOUNDARY t ɹ ʌ d ɪ ʃ ə n ə l WORD_BOUNDARY m ə d ɪ s ɪ n ə l WORD_BOUNDARY ɜː b WORD_BOUNDARY s ə n t WORD_BOUNDARY d̠ʒ ɑ n z WORD_BOUNDARY w ɔ ɹ t WORD_BOUNDARY ɔ l s oʊ WORD_BOUNDARY s iː m z WORD_BOUNDARY t ə WORD_BOUNDARY m eɪ k WORD_BOUNDARY k ɑ k p WORD_BOUNDARY n ɑ t WORD_BOUNDARY w ɜː k WORD_BOUNDARY æ z WORD_BOUNDARY w ɛ l WORD_BOUNDARY ð ɪ s WORD_BOUNDARY ɪ z WORD_BOUNDARY b ɪ k ʌ z WORD_BOUNDARY ʌ v ð ə WORD_BOUNDARY w eɪ WORD_BOUNDARY s ə n t WORD_BOUNDARY d̠ʒ ɑ n z WORD_BOUNDARY w ɔ ɹ t WORD_BOUNDARY ʌ f ɛ k t s WORD_BOUNDARY ð ə WORD_BOUNDARY l ɪ v ə ɹ WORD_BOUNDARY