St John's Wort and Birth Control
Today I went to my women's doctor and she told me that St Johns Wort (an over the counter alternative medicine to treat mild depression) can interfere greatly with the effectiveness of birth control.
When I heard this I was shocked! - I was taking it last year (st john's wort) briefly and was greatful to learn this. (I may have taken it in the future.)
I thought I would pass that information on, and ask for feedback if anyone else knows more.