St John's wort

Also Known As: St John's wort, Hypericum perforatum, Tipton's Weed, Chase-devil, Klamath weed, St. John's wort, Common St John's wort, Perforate St John's wort, Rosin rose, St Johns wort

St John's wort is the plant species Hypericum perforatum, and is also known as Tipton's weedrosin rosegoatweedchase-devil, or Klamath weed.[1]

With qualifiers, St John's wort is used to refer to any species of the genus Hypericum. Therefore, H. perforatum is sometimes called common St John's wort or perforate St John's wort to differentiate it.

Medicinal uses

Depression treatment use

St John's wort is widely known as an herbal treatment for depression. In some countries, such as Germany, it is commonly prescribed for mild depression, especially in children and adolescents.[6] It is proposed that the mechanism of action of St. John's wort is due to the inhibition of reuptake of certain neurotransmitters.[1]

A report[7] from the Cochrane Review states:

The available evidence suggests that the Hypericum extracts tested in the included trials a) are superior to placebo in patients with major depression; b) are similarly effective as standard antidepressants; and c) have fewer side-effects than standard antidepressants.
There are two issues that complicate the interpretation of our findings:
1) While the influence of precision on study results in placebo-controlled trials is less pronounced in this updated version of our review compared to the previous version (Linde 2005a), results from more precise trials still show smaller effects over placebo than less precise trials.
2) Results from German-language countries are considerably more favourable for Hypericum than trials from other countries.

In one study, St John's wort was not found to be effective for patients suffering from dysthymia, a less severe and more chronic variety of depression.[8] However, St John's wort has been shown to be effective in the treatment of mild to moderate depression in certain studies.

Standardized extracts are generally available over the counter, though in some countries (such as the Republic of Ireland) a prescription is required. Extracts are usually in tablet or capsuleform, and also in teabags and tinctures.

Major depressive disorder


An analysis of twenty-nine clinical trials with more than five thousand patients was conducted by Cochrane Collaboration. The review concluded that extracts of St John's wort were superior to placebo in patients with major depression. St John's wort had similar efficacy to standard antidepressants. The rate of side-effects was half that of newer SSRI antidepressants and one-fifth that of older tricyclic antidepressants.[7]

The National Center for Complementary and Alternative Medicine (NCCAM) and other NIH-affiliated organizations hold that St John's wort has minimal or no effects beyond placebo in the treatment of major depression.[9][10] This conclusion is based primarily on one trial of 340 volunteers, with negative outcome conducted by NCCAM.[11] The authors of the study themselves, as well as several others, pointed out the low assay sensitivity of this study, and how only limited conclusions can be drawn from its results.[12][13] The same study also indicated that sertraline (Zoloft) has no positive effects vs the same placebo.

A study published in 2005 found that St John's wort was significantly more effective than fluoxetine (Prozac).[14]


Most studies on St John's wort for treating depression uses doses of 300 mg of hydroalcoholic extract called WS 5570 (standardized contents of 3%–6% hyperforin and 0.12%–0.28%hypericin) one to three times daily to achieve a therapeutic effect.[15] No cases of overdose are known.[citation needed]

Other medical uses

St John's wort is being studied for effectiveness in the treatment of certain somatoform disorders. Results from the initial studies are mixed and still inconclusive; some research has found no effectiveness, other research has found a slight lightening of symptoms. Further study is needed and is being performed.

A major constituent chemical, hyperforin, may be useful for treatment of alcoholism, although dosage, safety and efficacy have not been studied.[16][17] Hyperforin has also displayed antibacterial properties against gram-positive bacteria, although dosage, safety and efficacy has not been studied.[18] Herbal medicine has also employed lipophilic extracts from St John's wort as a topical remedy for wounds, abrasions, burns, and muscle pain.[17] The positive effects that have been observed are generally attributed to hyperforin due to its possible antibacterial and anti-inflammatory effects.[17] For this reason hyperforin may be useful in the treatment of infected wounds and inflammatory skin diseases.[17] In response to hyperforin's incorporation into a new bath oil, a study to assess potential skin irritation was conducted which found good skin tolerance of St John's wort.[17]

randomized controlled trial of St John's wort found no significant difference between it and placebo in the management of ADHD symptoms over eight weeks. However, the St John's wort extract used in the study, originally confirmed to contain 0.3% hypericin, was allowed to degrade to levels of 0.13% hypericin and 0.14% hyperforin. Given that the level of hyperforin was not ascertained at the beginning of the study, and levels of both hyperforin and hypericin were well below that used in other studies, little can be determined based on this study alone.[19] Hypericin and pseudohypericin have shown both antiviral and antibacterial activities. It is believed that these molecules bind non-specifically to viral and cellular membranes and can result in photo-oxidation of the pathogens to kill them.[1]

A research team from the Universidad Complutense de Madrid (UCM) published a study entitled "Hypericum perforatum. Possible option against Parkinson's disease", which suggests that St John's wort has antioxidant active ingredients that could help reduce the neuronal degeneration caused by the disease.[20][21][22][23]

Recent evidence suggests that daily treatment with St John's wort may improve the most common physical and behavioural symptoms associated with premenstrual syndrome.[24]

St John's wort was found to be less effective than placebo, in a randomized, double-blind, placebo-controlled trial, for the treatment of irritable bowel syndrome.[25]

St John's wort alleviated age-related long-term memory impairment in rats.[26]

As an oil extract of the fresh flowers, St. John's wort is considered an anti-inflammatory and is traditionally used in the Balkans as a topical treatment for ailments such as bruises, cracks, stretch marks and hemorrhoids.

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