St. John's wort
St. John's wort (Hypericum perforatum) has a history of medicinal use dating back to ancient Greece, where it was used to treat a range of illnesses, including various "nervous disorders." St. John's wort also has antibacterial and antiviral properties and, because of its anti-inflammatory properties, has been used topically to help heal wounds and burns. St. John's wort is one of the most commonly purchased herbal products in the United States.
In recent years, there has been renewed interest in St. John's wort as a treatment for depression and there has been a great deal of scientific research on this topic. Most studies show that St. John's wort may be an effective treatment for mild-to-moderate depression, and has fewer side effects than most other prescription antidepressants. But the herb interacts with a wide variety of medications, so it is important to take it only under the guidance of a health care provider.
It is also important to note that severe depression (characterized by an inability to function with daily activities, thoughts of suicide or of harming yourself or others) should not be treated with herbs. Always see a doctor if your depression is serious (See "Precautions" section).
Several studies have shown that St. John's wort is effective in reducing symptoms in people with mild-to-moderate but not severe (or major) depression. In certain studies it appears to work as well as selective serotonin reuptake inhibitors (SSRIs), a popular type of antidepressant that includes fluoxetine (Prozac), citalopram (Celexa), and sertraline (Zoloft) without one of the most common side effects, loss of libido.
St. John's wort contains several chemicals, including hypericin, hyperforin and flavonoids. Researchers aren't exactly sure how St. John's wort works, although it has been suggested that the herb acts like an SSRI, making more serotonin, dopamine and norepinephrine available to the brain. These neurotransmitters help improve one's mood. Scientists thought that hypericin was responsible for these effects, but now they believe that other chemicals in St. John's wort have a beneficial effect.
Not all studies agree, however. In one study, St. John's wort was found to be no more effective than placebo for treating depression; however, in the same study, Zoloft also failed to show any benefit in treating depression. A number of other studies have compared St. John's wort to Prozac, Celexa, paroxetine (Paxil), and Zoloft, and found that the herb is just as effective as the drug. Other studies are ongoing.
St. John's wort has also shown promise in treating the following conditions, a few of which are related to depression.
- Bacterial and viral infections: In laboratory studies, St. John's wort has demonstrated the ability to fight certain infections, including some bacteria that are resistant to antibiotics. But it isn't known whether St. John's wort would have the same effect in people.
- HIV infection and AIDS: While laboratory research suggests that St. John's wort may kill or slow the growth of human immunodeficiency virus (HIV), St. John's wort interferes with medications used to treat people with the virus. In addition, it appears that the doses of St. John's wort that would be needed are so high that side effects become intolerable. For now, people with HIV or AIDS should not take St. John's wort.
- Premenstrual syndrome (PMS): An early study suggests that St. John's wort may help relieve physical and emotional symptoms of PMS, including cramps, irritability, food cravings, and breast tenderness.
- Menopause: Studies suggest that St. John's wort, especially in combination with black cohosh, is useful in alleviating mood and anxiety changes during menopause.
- Seasonal affective disorder (SAD): Used alone, St. John's wort has improved mood in those suffering from SAD (a type of depression that occurs during the winter months because of lack of sunlight). This condition is usually treated with photo (light) therapy. There is some evidence that using St. John's wort together with phototherapy produces even better results.
- Eczema, wounds, minor burns, hemorrhoids: St. John's wort has antibacterial properties and may also help fight inflammation. Applied topically (to the skin), it may relieve symptoms associated with minor wounds and skin irritation.
- Obsessive compulsive disorder, social phobia: St. John's wort has been proposed as a treatment for these conditions, but two preliminary studies in 2005 showed that the herb was not effective in relieving symptoms.
St. John's wort is a shrubby plant with clusters of yellow flowers that have oval, elongated petals. Scientists believe it is native to Europe, parts of Asia and Africa, and the western United States. The plant gets its name because it is often in full bloom around June 24, the day traditionally celebrated as the birthday of John the Baptist. Both the flowers and leaves are used for medicinal purposes.
What's It Made Of?
The best-studied active components are hypericin and pseudohypericin, found in both the leaves and flowers. Now research suggests, however, that these best-studied components may not be responsible for the plant's medicinal effects. Scientists are now studying St. John's wort's essential oils and flavonoids to see if they have benefits.
St. John's wort can be obtained in many forms: capsules, tablets, tinctures, teas, and oil-based skin lotions. Chopped or powdered forms of the dried herb are also available. Most products are standardized to contain 0.3% hypericin.
How to Take It
Most studies on St. John's wort have been conducted in adults. However, one study (more than 100 children under age 12) indicated that St. John's wort may be a safe and effective way of treating mild-to-moderate symptoms of depression in children. Talk to your doctor before giving St. John's wort to a child -- do not give your child a dose without medical supervision. Children being treated with St. John's wort should be carefully monitored for side effects, such as allergic reactions or upset stomach.
- Dry herb (in capsules or tablets): The usual dose for mild depression and mood disorders is 300 mg (standardized to 0.3% hypericin extract), 3 times per day, with meals. St. John's wort is available in time-release capsules.
- Liquid extract (1:1): 40 - 60 drops, 2 times per day.
- Tea: Pour one cup of boiling water over 2 - 4 tsp of dried St. John's wort and steep for 10 minutes. Drink up to 3 cups per day for 4 - 6 weeks.
- Oil or cream: To treat inflammation, as in wounds, burns or hemorrhoids, an oil-based preparation of St. John's wort can be applied topically.
It may take 3 - 4 weeks to feel any effects from St. John's wort.
The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, can trigger side effects and can interact with other herbs, supplements, or medications. For these reasons, you should take herbs with care, under the supervision of a health care provider.
St. John's wort is often used to treat depression. If your depression is severe -- causing problems with your daily life or accompanied by thoughts of suicide or of harming yourself or others -- you need to see a doctor immediately. St. John's wort should not be used to treat severe depression.
You should see a doctor to make sure you have the right diagnosis before taking St. John's wort. Your doctor can help you determine the right dose and make sure you are not taking any other medications that might interact with St. John's wort.
Side effects from St. John's wort are generally mild and include stomach upset, hives or other skin rash, fatigue, restlessness, headache, dry mouth, and feelings of dizziness or mental confusion. St. John's wort can also make the skin overly sensitive to sunlight (called photodermatitis). If you have light skin and are taking St. John's wort on a regular basis, be careful about sun exposure. Wear long sleeves and a hat, and use a sunscreen with at least SPF 15 or higher. Avoid sunlamps, tanning booths, and tanning beds.
Since St. John's wort can interact with medications used during surgery, you should stop taking it at least 5 days before surgery. Make sure your doctor and surgeon know you are taking St. John's wort.
Do not take St. John's wort if you have bipolar disorder.
St. John's wort should not be taken by women who are pregnant, trying to become pregnant, or breastfeeding.