St. John's Wort - What is it & How to use

What is it?

  • St. John’s wort is a plant with yellow flowers that has been used in traditional European medicine as far back as the ancient Greeks. The name St. John’s wort apparently refers to John the Baptist, as the plant blooms around the time of the feast of St. John the Baptist in late June.
  • Historically, St. John’s wort has been used for a variety of conditions, including kidney and lung ailments, insomnia, and depression, and to aid wound healing.
  • Currently, St. John’s wort is most often used as a dietary supplement for depression. People also use it as a dietary supplement for other conditions, including menopausal symptoms, attention-deficit hyperactivity disorder (ADHD), and obsessive-compulsive disorder. It is used topically for wound healing.
  • The flowering tops of St. John’s wort are used to prepare teas, tablets, capsules, and liquid extracts. Topical preparations are also available.
  • The results of studies on the effectiveness of St. John’s wort for depression are mixed. For more information, see the NCCIH fact sheet St. John’s Wort and Depression.
  • St. John’s wort has also been studied for conditions other than depression. For some, such as ADHD, irritable bowel syndrome, and quitting smoking, current evidence indicates that St. John’s wort is not helpful. For others, such as menopausal symptoms, premenstrual syndrome, and obsessive-compulsive disorder, the evidence is inconclusive.

Safety Concerns

  • St. John’s wort can weaken the effects of many medicines, including crucially important medicines such as
    • Antidepressants
    • Birth control pills
    • Cyclosporine, which prevents the body from rejecting transplanted organs
    • Digoxin, a heart medication
    • Some HIV drugs including indinavir
    • Some cancer medications including irinotecan
    • Warfarin, an anticoagulant (blood thinner).
  • Taking St. John’s wort with certain antidepressants or other drugs that affect serotonin, a substance produced by nerve cells, may lead to increased serotonin-related side effects, which may be potentially serious.
  • St. John’s wort may cause increased sensitivity to sunlight. Other side effects can include anxiety, dry mouth, dizziness, gastrointestinal symptoms, fatigue, headache, or sexual dysfunction.

* The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.