Of all the herbal supplements on the market today, none has as much potential for herb/drug interactions as the herb known as St. Johns wort. This unassuming little herb, with its yellow blossoms and dotted leaves, has at least the potential to interfere with common medications used to treat seizures, heart disease and cancer. It can render oral contraceptives completely useless and interfere with medications used to treat HIV.

If you are considering taking St. Johns wort for any purpose, here are 10 of the most common drugs known to interact with this supplement:

  • Chemotherapy (Used to treat some forms of cancer.)
  • Oral Contraceptives ("The Pill")
  • Indinavir (Used to treat HIV & AIDS.)
  • Warfarin (Used to thin blood and prevent blood clots.)
  • Cyclosporine (Used to prevent organ rejection after transplant surgery.)
  • Digoxin (Used to treat heart disease.)
  • Trazodone (Used mainly as an antidepressant.)
  • Phenelzine (Used to treat anxiety.)
  • Omeprazole (Used to treat GERD, ulcer and other digestive conditions.)
  • Statins (Used to lower cholesterol.)

This is, of course, a very brief look at some of the most common prescription medications experts warn you should never combine with St. Johns wort. Herbalists and physicians alike urge all people considering any herbal supplement to consult a licensed health care professional for more information.

Remember, St. Johns wort may be "natural" but that doesn't make it safe. Don't risk a potentially life-threatening interaction. Talk to your doctor for the information that is right for you.