St Johns Wort Health Benefits and Information

SCIENTIFIC NAME(S): Hypericum perforatum L. Family:Hypericaceae

COMMON NAME(S):St. John's wort, klamath weed, John's wort, amber touch-and-heal, goatweed, rosin rose, millepertuis

St . John's wort (Hypericum perforatum) , a common shrub-like perennial, bears bright yellow flowers that contain numerous therapeutic substances when dried. Europeans have used the herb for centuries to calm jangled nerves and heal wounds, among other ills. And so it's not surprising that North Americans have recently embraced its use as a treatment for depression and conditions associated with it.


This plant has been used as an herbal remedy for its anti-inflammatory and healing properties since the Middle Ages.Many noteworthy ancient herbalists, including Hippocrates and Pliny,recorded the medicinal properties of St. John's wort.It was noted for its wound-healing and diuretic properties, as well as for the treatment of neuralgic conditions such as back pain.In 1633, Gerard recorded the plant's use as a balm for burns. The oil of the plant was also popular during this time. An olive oil extract of the fresh flowers that acquires a reddish color after standing in the sunlight for several weeks has been taken internally for the treatment of anxiety but also has been applied externally to relieve inflammation and promote healing.Its topical application is believed to be particularly useful in the management of hemorrhoids. Although it is often listed as a folk treatment for cancer, there is no scientific evidence to document an antineoplastic effect.

Although it fell into disuse, a renewed Interest in St. John's wort occurred during the past decade, and it is now a component of numerous herbal preparations for the treatment of anxiety and depression. The plant has been used in traditional medicine as an antidepressant and diuretic and for the treatment of gastritis and insomnia. Since 1995, St. John's wort has become the most prescribed antidepressant in Germany. Sales have increased from $10 million to over $200 million in the past 8 years in the US. Since 1997, St. John's wort has been one of the leading herbal products; estimated sales of St. John's wort worldwide total $570 million.

Botany :-St. John's wort is a perennial native to Europe but is found throughout the US and parts of Canada. The plant is an aggressive weed found in the dry ground of roadsides, meadows, woods, and hedges. It generally grows to 0.3 to 0.61 m, except on the Pacific coast where it has been known to reach heights of 1.52 m.The plant has oval-shaped leaves and yields golden-yellow flowers that bloom from June to September. The petals contain black or yellow glandular dots and lines. Some sources say that the blooms are at their brightest coincidental with the birthday of John the Baptist (June 24).There are about 370 species in the genus Hypericum, which is derived from the Greek words, hyper and eikon meaning "over an apparition," alluding to the plant's ancient use to "ward off' evil spirits. Perforatum refers to the leaf's appearance; when held up to light, the translucent leaf glands resemble perforations. Harvest of the plant for medicinal purposes occurs in July and August; the plant must be dried immediately to avoid loss of potency. The dried herb consists of the plant's flowering tops.

Uses of St. John's Wort

St. John's wort has been primarily studied for its potential antidepressant and antiviral effects. There is information to show that St. John's wort is more effective than placebo, but evidence is still lacking regarding its efficacy compared with the standard antidepressants, partially due to ineffective dosing. In addition, at least 3 studies have shown that commercially available St. John's wort products vary considerably in content and may be standardized to the wrong component (hypericin instead of hyperforin). St. John's wort is still in the early stages of clinical trials investigating its effects against certain viruses, including HIV.

Drug Interactions

In February of 2000, the US Food and Drug Administration released a Public Health Advisory warning that there was a risk of dangerous interactions between St. John's wort and certain prescription medications. Researchers found that use of St. John's wort significantly reduces the effectiveness of some AIDS medications (indinavir and other antiretroviral agents). Because of the way St. John's wort operates in the body, the FDA also warned that it may also be unsafe to take it along with some common medications for heart disease, transplant rejection and cancer, among others. Drugs mentioned by name that are used in the treatment of mood disorders were:

  • The tricyclic antidepressants imipramine (Tofranil), amoxapine (Asendin), and amitriptyline (Elavil);
  • The anti-seizure medication carbamazepine (Tegretol), used as a mood stabilizer; and
  • The cancer medication Tamoxifen, which is being studied as a mood stabilizer.
It would be safer to assume that other drugs related to these would also be in the same category, including other tricyclics such as protriptyline (Vivactil) and nortriptyline (Pamelor) and the mood stabilizer oxcarbazepine (Trileptal).

Side Effects of St. John's Wort

Side effects are usually mild. Potential side effects include the following: dry mouth, dizziness, constipation, other GI symptoms, and confusion. Photosensitization also may occur. In clinical trials, side effects and medication discontinuation with St. John's wort were usually less than that observed with standard antidepressants. Other possible rare side effects include induction of mania and effects on male and female reproductive capabilities


The majority of clinical trials for the treatment of depression administered St. John's wort 300 mg tid standardized to 0.3% hypericin, but research has shown that products should contain 2% to 4% or more of hyperforin.

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.


Phototoxic activity by H. perforatum has been observed when tested on human keratinocytes. A review of the chemistry of phenanthroperylene quinones from hypericin reveals photosensory pigments. After oral administration, concentrations of hypericin in human serum and blister fluid have been detected. However, most reports of photosensitivity have been limited to those taking excessive quantities of H. perforatum, primarily to treat HIV. For example, IV (eg, 0.5 mg/kg twice weekly) and oral dosing (eg, 0.5 mg/kg/day) of H. perforatum caused significant phototoxicity in 30 HIV patients tested, with 16 of 30 discontinuing treatment for this reason.

A number of studies report no serious adverse effects. In a 22-patient study evaluating St. John's wort, 50% reported no side effects. Those reported include jitteriness, insomnia, change in bowel habits, or headache. In a study of 3250 patients taking St. John's wort for 1 month, fewer than 3% suffered from dry mouth, GI distress, or dizziness. In another review of clinical trials, St. John's wort was associated with fewer and milder adverse reactions as compared with any other conventional antidepressant. Adverse effects from H. perforatum were "rare and mild." No information on overdose was found. A case report describes acute neuropathy after sun exposure in a patient using St. John's wort. A review on photodermatitis in general is available, discussing mechanisms, clinical features, and treatment options. Various other reports regarding other adverse effect studies concerning St. John's wort are available, A 7-patient evaluation reports St. John's wort to be unlikely to inhibit cytochrome P-450 enzymes 2D6 and 3A4 activity. Reports of mania induction have been associated with St. John's wort. Uterotonic actions also have been reported, A letter discussing St. John's wort's use during pregnancy has been published. Due to lack of toxicity data in this area, St.John's wort is best avoided during pregnancy, Potent inhibition of sperm motility was observed from in vitro experimentation of St. John's wort, The volatile oil of St. John's wort is an irritant.

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