St. John's wort is a plant that is often used in herbal supplements to treat depression. It may work in a similar way as certain antidepressants, increasing the amount of a specific brain chemical called serotonin. However, more research is necessary to determine if it is effective at treating depression. Possible side effects include insomnia, nausea, and diarrhea.
What Is St. John's Wort?
St. John's wort (Hypericum perforatum) is an herbal supplement often used to treat depression, although it is sometimes used for other conditions as well. It is a yellow flowering plant that is native to Europe.
St. John's wort can work in several different ways, as it contains many different active compounds. In some ways, it works similarly to selective serotonin reuptake inhibitor (SSRI) antidepressants. This means that it may prevent nerve cells from reabsorbing serotonin (a naturally occurring neurotransmitter brain chemical). By preventing the reabsorption of serotonin, St. John's wort increases the amount of serotonin that is available and active in the brain. This may help relieve some of the symptoms of depression.
It may also affect several naturally occurring chemicals in the body. It is not entirely clear how these other effects contribute to the properties of St. John's wort.
Is St. John's Wort Effective?
It is not clear if St. John's wort is really effective at treating depression. There is quite a bit of evidence suggesting that it is effective for depression treatment. However, a few important studies have shown that it is no more effective than a placebo (a "sugar pill" that does not contain any active ingredients). Although early research suggests that St. John's wort may be useful for a few other conditions, more research is necessary to confirm this.
Written by/reviewed by: Kristi Monson, PharmD;Arthur Schoenstadt, MD
Last reviewed by: KristiMonson, PharmD;
List of references (click here):
Jellin JM, editor. Pharmacist's Letter/Prescriber's Letter Natural Medicines Comprehensive Database Web site. Available at: http://naturaldatabase.com/. Accessed February 25, 2008.
National Center for Complimentary and Alternative Medicine. National Institutes of Health. Herbs at a glance: St. John's wort (July 2005). NCCAM Web site. Available at: http://nccam.nih.gov/health/stjohnswort/. Accessed February 25, 2008.
National Center for Complimentary and Alternative Medicine. National Institutes of Health. St. John's wort and depression (December 2007). NCCAM Web site. Available at: http://nccam.nih.gov/health/stjohnswort/sjwataglance.htm. Accessed February 25, 2008.
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