St John's wart (Hypericum perforatum) is also known as goat weed, amber touch-and-heal and Klamath weed. It is used in the treatment of mild to moderate depression. It is marketed as a dietary supplement.

Medicinal constituents: Flavonoids, xanthones and naphthodinathrone (Hypericin). Mechanism of action of St John's wort is not completely understood yet; it is believed to stimulate cholinergic system in central nervous system.

Uses: To treat depression and anxiety and sleep disorders.

Availability: St John's wart extract is available as standardized hypericin extracts and capsules.

Side effects: Increased sensitivity to sunlight. Insomnia, irritability, anxiety and gastrointestinal disturbances

Drug interactions: Possible interactions noted with: Monoamine oxidase inhibitors Selective serotonin reuptake inhibitors (SSRI) Oral contraceptive pills Digoxin Protease inhibitors used for the treatment of HIV

Cautions: Talk with your doctor before using St John's wart. Discuss your other health problems and medications you are taking. Do not take without talking to your doctor if you are pregnant or planning for pregnancy or breast feeding.