Dried rhizome and roots of Piper methysticum, a shrub native to Oceania and known for its anti-anxiety and sedative properties. Heavy usage results in some adverse effects. It contains ALKALOIDS; LACTONES; kawain, methysticin, mucilage, STARCH, and yangonin. Kava is also the name of the pungent beverage prepared from the plant's roots.

(tonga) An herb native to islands in the South Pacific. Substances taken from the root have been used in some cultures to relieve stress, anxiety, tension, sleeplessness, and problems of menopause. Kava kava may increase the effect of alcohol and of certain drugs used to treat anxiety and depression. The U.S. Food and Drug Administration advises users that kava kava may cause severe liver damage. The scientific name is Piper methysticum.

Kava comes from the root of a shrub (Piper methysticum) that grows in the South Pacific. It is ingested as a tea or in capsule form. Active ingredients are thought to be kavalactones.