St John’s wort - Visit our shop for these products

In just a decade or so, this herbal antidepressant has risen from obscurity to tabloid stardom, being dubbed by the popular press as 'Nature’s Prozac'. In Germany, St John’s wort (Hypericum perforatum) is the country’s best-selling antidepressant, beating even Prozac itself.

It works just as well as—and frequently better than—conventional antidepressants, and has fewer side-effects for cases of mild to moderate depression.

Being a herb, St John’s wort is classified as a food and therefore doesn’t have to be tested for its toxicity—unlike drugs. However, the problem for its opponents is that the plant appears to be not only safe, but also relatively free of side-effects.

The one major adverse effect is an increased sensitivity to light, potentially causing reddening of the skin in sunlight. However, the amounts required to provoke this reaction are at least two to three times the recommended daily dose.

Overall, according to the British Medical Journal, fewer than one-fifth of patients experience side-effects from H. perforatum, compared with more than half of those taking drugs.

Detractors have turned to the potential problems when taking the herb at the same time as other drugs. Concerns now centre on the discovery that the plant can prevent other medicines from working. This is because Hypericum affects a particular enzyme in the liver, causing the body to metabolize poisons more quickly. The most commonly used drugs affected are the heart drug digoxin, anticoagulants such as warfarin, and epilepsy drugs. Some people taking oral contraceptives have reported irregular bleeding. A recent study says that, in theory, St John’s wort may interact with as many as half of all prescribed drugs and cautions against taking it in conjunction with other medicines.

The generally recommended dosage of St John’s wort is about 900 mg/day (or 300 mg three times a day). Check that the capsules contain the ‘standardized’ hypericin content of 0.3 per cent hypericin (the major active ingredient), as well as 5 per cent hyperforin, the other, recently discovered, key natural ingredient.