Medical uses of st Johns wort

Other Common Names: Binbirdelikotu, Common St Johnswort, Hiperico, Hypericum, Klamath Weed, Perforate St John's-wort, Klamath Weed, Hypericum perforatum

Range: Britain; and throughout Europe and Asia; USA.

Habitat: Open woods, hedgebanks and grassland, in dry sunny places, usually on calcareous soils.

There are many ancient superstitions regarding this herb. Its name Hyperieum is derived from the Greek and means 'over an apparition,' a reference to the belief that the herb was so obnoxious to evil spirits that a whiff of it would cause them to fly.

There is considerable public interest in the United States in claims that extracts of the herb St. John's wort may be an effective treatment for depression. In Europe - where the herb is now widely prescribed - a number of studies have been conducted that support the treatment efficacy of certain St. John's wort extracts. In the United States, St. John's wort is not a prescription medication, but is sold in health food stores and pharmacies as an herbal tea or nutritional supplement, which the U.S. Food & Drug Administration (FDA) does not regulate.

St. John's wort has a long history of herbal use. It fell out of favor in the nineteenth century but recent research has brought it back to prominence as an extremely valuable remedy for nervous problems. An overview of 23 clinical studies in Europe, published in the British Medical Journal (Vol. 313, August 3, 1996), found that the herb might be useful in cases of mild to moderate depression. The studies, which included 1,757 outpatients, reported that St. John's wort was superior to placebo and appeared to produce fewer side effects than standard antidepressants.

Depression, at least in its milder forms, is a condition that seems to afflict many Americans. In this country, the disease is the fourth most likely reason for one to consult a family physician and costs our economy more than chronic respiratory illness, diabetes, arthritis, or hypertension. The treatment and rehabilitation expenses in the United States exceed $12 billion annually.

More than a dozen prescription drugs are routinely used to treat America's depression. All of them are synthetic, and they all produce more or less unpleasant side effects ranging from skin rashes to overtly violent behavior. Meanwhile, in Germany the most popular prescription drug of any type, natural or synthetic, for the treatment of depression is a concentrated extract of the flowers and leaves of St. John's wort, often simply called hypericum. More than 200,000 prescriptions per month are filled for a single brand (Jarsin) there compared to about 30,000 per month for fluoxetine (Prozac). This figure does not include sales of other hypericum products, whether prescribed or self-selected. Actually, 80-90% of the sales in Germany are prescriptions, which allows their cost to be reimbursed by the health insurance system.

The plant contains many biologically active compounds including rutin, pectin, choline, sitosterol, hypericin and pseudohypericin. These last two compounds have been shown to have potent anti-retroviral activity without serious side effects and they are being researched in the treatment of AIDS.



The herb's multiple constituents apparently function in several different ways. Initially, St. John's wort was thought to act as a monoamine oxidase (MAO) inhibitor. This effect has now been shown to be insignificant. Some evidence supports its effect as a selective serotonin reuptake inhibitor (SSRI).

Although St. John's wort is marketed as a drug in Germany and has been approved there by the German equivalent of our Food and Drug Administration for the treatment of depression, anxiety, and nervous unrest, it is sold in the United States only as a dietary supplement. The most effective preparations are capsules containing an extract of the herb standardized on the basis of 0.3% hypericin. Dosage is 300-900 mg daily. Improvement of mild to moderate depression should result after 2 to 6 weeks of treatment

The flowers and leaves are analgesic, antiseptic, antispasmodic, aromatic, astringent, cholagogue, digestive, diuretic, expectorant, nervine, resolvent, sedative, stimulant, vermifuge and vulnerary. The herb is used in treating a wide range of disorders, including pulmonary complaints, bladder problems, diarrhoea and nervous depression. It is also very effectual in treating overnight incontinence of urine in children. Externally, it is used in fomentations to dispel herd tumours, caked breasts and bruising. The flowering shoots are harvested in early summer and dried for later use. Use the plant with caution and do not prescribe it for patients with chronic depression. The plant was used to procure an abortion by some native North Americans, so it is best not used by pregnant women. See also the notes on toxicity.

A tea or tincture of the fresh flowers is a popular treatment for external ulcers, burns, wounds (especially those with severed nerve tissue), sores, bruises and cramps. An infusion of the flowers in olive oil is applied externally to wounds, sores, ulcers, swellings and rheumatism. It is also valued in the treatment of sunburn and as a cosmetic preparation to the skin.

A homeopathic remedy is made from the fresh whole flowering plant. It is used in the treatment of injuries, bites, stings etc and is said to be the first remedy to consider when nerve-rich areas such as the spine, eyes, fingers etc are injured

Known Hazards: Skin contact with the sap, or ingestion of the plant, can cause photosensitivity in some people. The European studies reported that some patients have complained of mild problems with dry mouth, dizziness, gastrointestinal symptoms, increased sensitivity to sunlight, fatigue, and/or confusion.

Many "natural" substances can have harmful effects, especially if taken in large quantities or with other medications. Even too much vitamin A, for example, can be damaging. St. John's wort, like certain other herbal treatments, is now known to adversely interact with or change blood levels of particular prescription drugs, such as indinavir and cyclosporine, as discussed below.

Further, NIH findings on indinavir that were reported in the Lancet article, as well as other information in the medical literature, suggest that St. John's wort may be an inducer of the metabolic pathway cytochrome P450. Consequently, the combined use of St. John's wort and other drugs metabolized via this route could result in harmful effects. These may include oral contraceptives; medications to treat heart disease, depression, seizures, and certain cancers; and those to prevent organ transplant rejection.

The Food and Drug Administration would like to inform you about results from a study conducted by The National Institutes of Health (NIH) that showed a significant drug interaction between St John's wort (hypericum perforatum), an herbal product sold as a dietary supplement, and indinavir, a protease inhibitor used to treat HIV infection. In this study, concomitant administration of St. John's wort and indinavir substantially decreased indinavir plasma concentrations, potentially due to induction of the cytochrome P450 metabolic pathway. For additional information on this study please refer to the February 12, 2000 Lancet publication (Piscitelli, et al).



Given the research to date, it is evident that "natural" does not always mean "safe." Alternative medical treatments require more research, and people are well advised to seek competent medical supervision before trying them. The National Institute of Mental Health (NIMH) also urges individuals who are already taking St. John's wort with any of the above types of medications to contact their doctors immediately for medical direction. Health care providers are strongly advised to alert patients to these potential drug interactions, until additional research is done.

Another caution against using St. John's wort for the treatment of depression is that the herb is not a proven therapy for the disorder. If major depression is not adequately treated, it can become debilitating and, in some cases, lead to suicide. Proven treatments most commonly used are prescription antidepressants, specific psychotherapies (such as cognitive-behavioral therapy and interpersonal therapy), or a combination of both. Also, because other medical conditions, such as thyroid disorders, can mimic depression, anyone with symptoms of depression should receive a thorough medical examination before beginning any treatment, in order to rule out other possible causes.

  • Plants For A Future - A Resource and Information Centre for Edible and other useful plants.
  • Tyler, V.E. 1999. Herbs affecting the central nervous system. p. 442�449. In: J. Janick (ed.), Perspectives on new crops and new uses. ASHS Press, Alexandria, VA.