St. John's wort may make the side effects of antidepressants worse. It may make the depression return. St. John's wort may affect how well birth control pills work (putting women at risk of pregnancy). It may affect how well medicines work to treat cancer, HIV infection, heart disease and other problems.
Like regular medicines, herbs and vitamins can cause allergic reactions, side effects and bad interactions. Try to think of them like medicine.
Before using any herbs or vitamins, ask your doctor or pharmacist if it’s safe to combine them with the medicine(s) you already take.
Whenever you get a new prescription, tell your doctor and pharmacist about any herbs or vitamins you take.
