There are a couple posts today about supplement and prescription medicine interactions. As mentioned by several posters, supplements are not regulated by the FDA, something "natural" doesn't mean it is harmless, and the same supplement quality/ quantity can vary from one manufacturer to another. When I was practicing medicine, I often asked people about alternative medications/vitamins/etc. that they were taking. Polls show people are embarassed sometimes to tell their healthcare providers what they are taking but if their MDs,etc. are responsible they shouldn't make you feel bad for trying other things and should at least warn you about known interactions. In my own case, I give my primary MD (who is traditional but has other patients taking alt. meds in her clinic) and my Chinese medicine doctor lists of what I am taking and besides me looking things up, they also cross-check meds for me. I also bring this list to specialist visits regardless of what these MDs think. One other option would also be to talk to your pharmacist.