St. John's Wort

Botanical name(s):

Hypericum Perforatum. Family: Hypericaceae

Other name(s):

amber, goatweed, hardhay, hyperici herba, klamath weed, tipton weed

General description

St. John's wort is an herb with a five-petaled yellow flower that grows in much of the world. It is named after St. John the Baptist because it blooms around his celebration day (June 24). The medicinal element of the plant consists of the dried above-ground parts, including the stem, petals, and flowers.

Two constituents that play a significant role are hypericin and hyperforin. Although hypericin was formerly thought to be the component of St. John's wort principally responsible for its action, it is now understood that hyperforin, adhyperforin, and several other related compounds are the primary active constituents. These appear to modulate the effects of serotonin, dopamine, and norepinephrine. 

Medically valid uses

St. John's wort has been used successfully to treat mild to moderate depression. Several studies have indicated that it is as effective as many prescription antidepressants when used to treat mild or moderate depression. St. John's wort is not useful for treating major or severe depression. 

Externally, oily hypericum preparations have been used in the treatment of injuries, muscle pain, and first-degree burns.

Unsubstantiated claims

Please note that this section reports on claims that have NOT yet been substantiated through scientific studies.

Traditionally, St. John's wort has been used as a muscle relaxant to relieve menstrual cramps and as a mild tranquilizer.

Although without scientific confirmation, it is also claimed to function as a nerve tonic (has a beneficial effect on the nervous system), as an anti-inflammatory (decreases swelling), as an astringent (contracts the tissues or canals of the body), as a vulnerary (brings about healing in wounds and inflammation), as a antineoplastic (cancer fighting) and as an antiviral. For instance, it is claimed that it may possibly help inhibit viral infections, including herpes and HIV.

St. John's wort has also been claimed to be good for nerve pain (neuralgia), anxiety, tension, nervous debility, stress, irritability, and insomnia. It is also claimed to ease the pain associated with sciatica, rheumatoid arthritis, menstruation, itching and burning of hemorrhoids, and itching and irritation caused by vaginitis.

When used externally, St. John's wort has been claimed to possibly speed the healing of bruises, wounds, varicose veins, mild burns, and sunburns.

Dosing format

St. John's wort comes in many forms including oil, dried herb, tea, and salve.

Results are gradual and may take four to six weeks before positive changes are noticeable. If no results are achieved, alternative therapy should be considered.

Side effects, toxicity, and interactions

St. John's wort has been shown to interfere with medications that prevent organ rejection after an organ transplant. If you will be getting an organ transplant or have had one, do not use St. John's wort. It can also interfere with the metabolism of many other drugs, including birth control pills, digoxin, seizure-control drugs, blood thinners, drugs to treat HIV, antidepressants, and cancer chemotherapy drugs.

St. John's wort can cause sensitivity to the sun when taken in large amounts, especially in fair-skinned people. Avoid sun exposure as much as possible, and use a sunscreen whenever sun exposure is expected. Do not take enormous quantities of St. John's wort. Follow package directions.

Do not take St. John's wort if you suffer from major depression, or are taking another psychoactive agent such as a conventional antidepressant.

Women who are pregnant or breastfeeding should consult a physician before taking any herbal supplements.

St. John's wort can interfere with the absorption of iron and other minerals.

Additional information

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