Kava (Piper methysticum) or kavakava is a ﬂowering shrub related to the common black pepper plant, indigenous to Polynesia, the Sandwich Islands, and various other island groups in the South Paciﬁc and Indian Oceans. Its root has been used by island natives for thousands of years to prepare an intoxicating tea used before important religious ceremonies. Traditional preparation involves chewing the root and then spitting it out into a bowl fashioned from a coconut half, where it is combined with water. The resulting infusion acts as a mild stimulant, but also has a soporiﬁc and narcotic effect. This results in the user feeling both mild euphoria and tranquility. The muscles relax, but the user remains alert and fully in control. The plant resin is also sometimes used as a local anesthetic and in the treatment of urinary-tract infections and gonorrhea.
Kava became popular among herbal medicine enthusiasts in the United States and Europe in the 1990s as an alternative to prescription anti-anxiety medications and tranquilizers. Multiple clinical trials appeared to support kava’s superiority to a placebo in reducing anxiety and promoting relaxation, and it became widely available in drugstores and supermarkets. By 2002, however, some troubling cases of liver damage, including hepatitis, cirrhosis, and total liver failure, led previously silent regulatory agencies, including the FDA, to warn that there may be some risks associated with its use, especially for people who already have liver problems or are taking drugs that can affect the liver. The action was prompted by over twenty-ﬁve adverse event reports in various countries, including at least ﬁve cases in which liver transplantation was necessary. Though such problems are rare, they are severe enough that some countries, including the United Kingdom, have ended the sale of kava products. Kava remains widely available in the United States.
- FDA/CFSAN. “Consumer Advisory: Kava-containing Food Supplements May Be Associated with Severe Liver Injury.” https://www.fda.gov/food/resourcesforyou/consumers/ucm085482.htm, 2002.