St.-John's-wort has interested herbalists since the first-century Greek physicians Galen and Dioscorides recommended it as a diuretic, wound-healing herb, and treatment for menstrual disorders. In nineteenthcentury America, it was used by physicians for wound healing, especially for lacerations involving damaged nerves, and as a diuretic, astringent, and mild sedative.

St.-John's-wort is anti-viral which is especially good for gonorrhea. It relieves pain, anxiety, nervous tension, and is used in treating AIDS and depression but must be taken for several months to get full effect.

St.-John's-wort has gotten a lot of press in recent years for its antidepressant effect. The active component of the plant is hypericin which is used for its antidepressant effect.

Recently over nineteen double-blind clinical trials in humans indicate that standardized St.-John'swort preparations are safe and effective in the treatment of depression and have far fewer side effects than conventional drugs. A recent clinical trial confirmed the results of previously reported studies. In a randomized placebo-controlled double-blind study of 105 outpatients diagnosed with mild to moderate depression or temporary depressive moods, patients were given the equivalent of 300 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 improved, but only 28 percent of the placebo group responded. Patients who took the extract felt significant improvement in depressive mood indicators such as feelings of sadness, hopelessness, helplessness, and uselessness, as well as fear and difficult or disturbed sleep. No significant side effects were observed. Researchers concluded that St.-John's-wort extract, compared with synthetic antidepressants, produced side effects of minor significance and can be recommended for the treatment of mild and moderate depression. Externally, St.-John's-wort oil is used for the treatment of wounds, abrasions, and firstdegree burns.

St.-John's-wort seems to work by inhibition of serotonin uptake by post-synaptic receptors. In one study, hypericum caused a 50% inhibition of serotonin uptake by rat synapses.

It is not recommended to be used with concomitant antidepressant medications. Excessive doses of this product may potentiate existing MAOI antidepressant activity. People can become photosensitized by this product, particularly in higher doses and if the patients are fair skinned.