A supplement to The Herb Companion from the American Botanical Council and the Herb Research Foundation. The science and tradition behind herbal health solutions.
St. John’s wort (Hypericum perforatum) is a wildflower, a weed, and an herb with a long history. The first-century Greek physicians Galen and Dioscorides recommended it as a diuretic, wound healer, and treatment for menstrual disorders. In the sixteenth century, Paracelsus, who ushered in the era of mineral medicines, used St. John’s wort externally to treat wounds and contusions. Early Christians named the plant in honor of John the Baptist because they believed the flowers released their blood-red oil on August 29, the anniversary of the saint’s beheading.
During the Middle Ages, remarkable, even mystical properties were bestowed on the herb. It was used as a talisman to protect the bearer from demons. Harvesting often took place on a day with religious significance. (Whether a specific holy day was simply the best time to harvest or imbued the herb with greater power is open to speculation.) St. John’s wort was harvested on St. John’s day (June 24), its period of peak bloom. Superstition held that if a sprig of the herb were placed under the pillow on St. John’s Eve, St. John himself might appear in a dream, blessing the dreamer for another year.
The genus Hypericum contains more than 400 species of trees, shrubs, and herbs, many of which are grown as ornamentals. H. perforatum is a much-branched perennial herb growing 1 to 3 feet tall. The leaves bear translucent dots that are easily seen by holding the leaves up to a light; these are the “perforations” that gave rise to the specific epithet perforatum.
St. John’s wort is native to Europe, occurring there except in the extreme north. It was introduced by early European settlers in North America, where it has naturalized in waste places and along roadsides. Now found in Asia, Africa, North and South America, and Australia, the herb has aggressively invaded rangelands, painting dry summer pastures with a blaze of yellow flowers. Beautiful it may be, but ranchers despise St. John’s wort because light-skinned livestock that eat the plants become sensitive to light, causing swelling and blindness and often death from starvation. Dark-skinned animals are unaffected. This photodermatitis results from the interaction of sunlight and oxygen with the red pigment hypericin (the condition has been called “hypericism”). External contact with the plant does not affect animals.
U.S. ranchers have lost sheep worth millions of dollars through poisoning by the plant they know as Klamath weed, so it’s not surprising that most North American scientific studies of St.-John’s-wort have focused on how to eradicate it. In Canada and the United States, a beetle (Chrysolina quadrigemina), whose sole food is St. John’s wort, has been used as a natural biological control.
Given the superstitions surrounding the herb, physicians had dismissed it as a folk medicine by the mid–nineteenth century. Interest in the medicinal uses of the plant was kept alive by Eclectic medical practitioners in the United States, who found it useful for healing wounds, especially lacerations involving nerve damage, as well as for its diuretic, astringent, and sedative properties. In 1938, a survey by a German physician found that St. John’s wort preparations were being utilized in Germany for neuroses, general restlessness, insomnia, and mental or emotional disorders caused by “excessive intellectual efforts”.
Today, St. John’s wort is a common ingredient of European home remedies and pharmacy preparations. Alcohol tinctures and vegetable oil extracts of the flowers are official remedies in the pharmacopeias of many countries of Eastern Europe. Vegetable oil preparations are used externally to treat hemorrhoids and inflammation. A tea made from the plant serves as a mild nerve tonic for anxiety, depression, and insomnia, and as a diuretic and treatment for gastritis. In Russia, preparations are widely prescribed as antibacterials.
In the past decade, most of the scientific attention on St. John’s wort has concerned its use to treat depression. According to the German government’s official monograph, a dose of 2 to 4 g of the herb is effective against mild depression or nervous disturbances. However, while the effects of conventional medicines may be experienced immediately or within a few hours of treatment, effects of herbal antidepressants may not be evident until two to three months after beginning treatment. Avoiding the side effects associated with taking conventional antidepressants makes the wait worthwhile for some people.
According to one controversial theory, some cases of clinical depression can be ascribed to a deficiency in certain neurotransmitters (substances that transmit nerve impulses). A class of antidepressants, called monoamine oxidase (MAO) inhibitors, increases the concentration of neurotransmitters in the central nervous system. The conventional antidepressant drug Prozac is an MAO inhibitor, and a 1984 study showed that hypericin, which is abundant in the flowers of St. John’s wort, inhibits two types of mao. This ability may be one basis for the herb’s effectiveness as an antidepressant.
After preliminary trials in 1984 suggested that a standardized extract of St. John’s wort reduced instances of anxiety including depression, insomnia, and feelings of worthlessness, dozens of controlled clinical studies subsequently examined the effectiveness of the herb in relieving depression. Unfortunately, some of them used preparations containing both St. John’s wort and valerian, so it was not possible in these cases to attribute beneficial effects to a single herb. While these studies showed benefits with few or no side effects, well-designed, rigorous clinical studies of St. John’s wort alone did not begin until 1989.
A 1994 randomized, placebo-controlled, double-blind study by a psychiatrist, an internist, and a general practitioner in Austria evaluated the effects of St.-John’s-wort on 105 outpatients diagnosed with mild to moderate depression or temporary depressive moods. Patients were given the equivalent of 900 mg of St. John’s wort extract (standardized to a hypericin content of 0.9 mg) or a placebo daily for four weeks. In the treatment group, 67 percent felt significantly less sad, hopeless, helpless, or useless, were less fearful, and slept better compared to 28 percent in the placebo group. The extract caused only minor side effects. The researchers deemed the extract effective for treating mild and moderate depression but unsuitable for treating severe depression, whose symptoms can include delusion, increased risk of suicide, and interference with a profession or family life. In these cases, intensive psychiatric treatment is required.
A 1995 evaluation of all controlled clinical trials involving St. John’s wort to date—eighteen in all—found eleven studies that met the author’s rigorous criteria. He concluded that St.-John’s-wort is safe and effective for the symptomatic treatment of mild to moderate forms of depression—as effective as standard antidepressant medications and with milder adverse reactions.
Herbalists have long used St. John’s wort oil to speed the healing of minor wounds and sores. The German government’s Commission E allows external St.-John’s-wort preparations to be labeled for the treatment of sharp or abrasive wounds, muscular pain, and first-degree burns.
The practice of soaking St. John’s wort flowers in olive oil, infusing the oil in the sun, then anointing the oil on wounds dates at least to the time of the first edition of Gerard’s Herball (1597). This “red oil” or “hypericum liniment” was still available in pharmacies in the early twentieth century.
To make St. John’s wort oil, place one cup of the freshly cut or crushed flowers in a lidded jar, cover them with olive oil, and put on the lid. Place the jar in the sun or a warm area. Shake it once a day. The oil will turn a deep red. After two to three weeks, press and strain the flowers from the oil. Store the oil in a dark, closed container in a cool place.
To use the oil to treat minor cuts, wounds, and burns, dab it onto the skin with a cotton ball. Reapply as needed, two to three times a day.
Although photodermatitis has not been reported in humans who have eaten St. John’s wort leaves, pure synthetic hypericin has produced this reaction. Fair-skinned individuals should be especially aware of the potential problem and not go out in the sun while taking the herb internally.
Depression is a condition that requires professional medical diagnosis and treatment. If you are depressed and are taking or contemplating taking St. John’s wort, discuss it with your health-care professional. St. John’s wort should not be taken at the same time as conventional antidepressant drugs, especially MAO inhibitors such as Prozac.
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Ernst, E. “St.-John’s-wort, An Anti-Depressant? A Systematic, Criteria-Based Review”. Phytomedicine 1995, 2(1): 67–71.
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Researchers in Düsseldorf, Germany, have concluded that an extract of kava-kava, or simply kava (Piper methysticum), is a suitable tool for general practitioners to use to treat patients with anxiety and tension. In a double-blind, placebo-controlled clinical study, fifty-eight patients with anxiety not attributable to mental disorders were given 100 mg of either a kava root extract or a placebo three times a day for four weeks.
After one week of treatment, symptoms of anxiety and depression had declined significantly in the treatment group, and they declined further in the remaining weeks of the study. None of the adverse reactions sometimes associated with tranquilizers and antidepressants was observed over the four-week period. Participants in the placebo group were unchanged.
Kava has been used for thousands of years in the South Pacific, where a traditional beverage of the grated root is often served at parties and ceremonial festivities.(1)
(1) Lehmann, E., et al. “Efficacy of a Special Kava Extract (Piper methysticum) in Patients with States of Anxiety, Tension and Excitedness of Non-Mental Origin: A Double-Blind Placebo-Controlled Study of Four Weeks Treatment”. Phytomedicine 1996, 3(2):113–119.
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Herbs for Heath
“Herbs for Health” is offered bimonthly by the American Botanical Council and the Herb Research Foundation as a supplement to The Herb Companion.
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“Herbs for Health” is intended as an educational service, not a source of medical advice or a guide for self-medication. Please consult a qualified health-care professional for treatment of any serious health problems. For further information on any of the topics in “Herbs for Health”, write the American Botanical Council or the Herb Research Foundation.