Any changes to diet can affect medications that are used, including homeopathic remedies. Consulting a medical professional before taking any new herbs or vitamins is a sure way to guarantee that you are not ingesting things that will keep your birth control from working.
Avoid any herbs or treatments that are known for increasing fertility. Black Cohosh, Dong Quai and Evening Primrose Oil are just some herbs that increase fertility. Make sure that any supplements or herbs that you are taking do not contain these items.
Many antibiotics will also decrease the effectiveness of birth control. The antibiotics change the hormones of the birth control. You must either avoid taking antibiotics or use a backup form of birth control during this period. Sage, thyme, oregano and parsley are all herbs that are considered antibacterial.
Estrogen Containing Herbs
Herbs containing estrogen will directly effect how the birth control works. These herbs will affect your estrogen levels, which will make your birth control less effective. Licorice and St. Johns Wort contain estrogen, as do Fennel and Hops. Licorice has even more dangerous side effects such as increasing blood pressure and lowering potassium levels. St. Johns Wort can cause irregular bleeding as well as lowering effectiveness of contraception.
Contact a Professional
When on medication such as birth control, it is very important to consult a medical professional when adding items to your diet. Letting your doctor know that you are on birth control will help her advise you of what you should and should not take. Herbal supplements can be very helpful if the right ones are taken after a doctor's consultation.