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Herbs & Supplements «St Johns Wort Health Benefits and Information»

Native to Europe, St. John's wort is now found growing in dry areas such as the edges of fields and along roadsides in many temperate climates throughout the world. It is a shrub-like weed that spreads rapidly and invades cultivated land unless controlled. St. John's wort blooms from late May through September, depending on the climate. It was believed to bloom on the birth day of St. John the Baptist, June 24 - hence the name St. John's wort.

Best known for use as a mild antidepressant, St. John's wort is also being studied for its possible affects on other mood disorders such as anxiety and obsessive-compulsive disorder. St. John's wort herbal supplements are among the leading medicines used in Germany to relieve the symptoms of mild to moderate depression. People taking St. John's wort show an improvement in mood and ability to carry out their daily lives. Symptoms including sadness, hopelessness, worthlessness, exhaustion, and poor sleep also may decrease with the usage of St. John's wort. Used topically, it may have antiviral and antibacterial effects.

The major active ingredients in St. John's wort include hypericin and other dianthrones, flavonoids, xanthones, and hyperforin. For many years researchers believed the antidepressant properties of St. John's wort were a result of its hypericin contnet and the inhibition of the enzyme monoamine oxidase, however, more recent research suggests that its antidepressant actions may be a result of other active constituents, such as hyperforin, and flavonoids. Clinical studies suggest that St. John's wort extracts may exert their antidepressant actions by inhibiting the reuptake of the neurotransmitters serotonin, norepinephrine, and dopamine. This action may be due to hyperforin. St. John's wort's may work as an antidepressant, by making more of hyperforin (a neurotransmitter) available to the brain.

Dosage and Administration

A common recommendation for St. John's wort extract when taken in connecton with mild to moderate depression is 500-1,000 mg per day. Results may be noted as early as two weeks but may take longer. You should consult with a health care professional to determine how long to use this supplement. For more severe depression, higher intakes may be required, under the supervision of a physician.

We recommend consulting with a doctor before starting any supplement.


There may be a number drug interactions with St. John's wort that are not yet know. St. John's wort stimulates a drug-metabolizing enzyme that metabolizes at least 50 of the drugs on the market. Based on this fact alone, St. John's wort could possibley interfere with a number of medications. Consult with a qualified medical professional before supplementing with St. John's wort.

Supporting Literature

Brown DJ. Herbal Prescriptions for Better Health. Rocklin, CA: Prima Publishing, 1996, 159-165.

Chatterjee SS, Koch E, Noldner M, et al. Hyperforin with hypericum extract: Interactions with some neurotransmitter systems. Quart Rev Nat Med 1997;Summer:110.

Holzl J, Demisch L, Gollnik B. Investigations about antidepressive and mood changing effects of Hypericum perforatum. Planta Med 1989;55:643.

Müller WE, Rolli M, Schäfer C, Hafner U. Effects of hypericum extract (LI 160) in biochemical models of antidepressant activity. Pharmacopsychiatry 1997;30(suppl):102-107.

Müller WE, Singer A, Wonnemann M, et al. Hyperforin represents the neurotransmitter reuptake inhibiting constituent of hypericum extract. Pharmacopsychiatry 1998;31(suppl):16-21.

Suzuki O, Katsumata Y, Oya M. Inhibition of monoamine oxidase by hypericin. Planta Med 1984;50:272-274.