• Basic Info
• Top Questions
• Interactions

Category

Herbs & Supplements

Alternate Title

Piper methysticum

Synonyms

(+) -dihydrokawain-5-ol, 11-methoxy-5, 5-hydroxydihydrokawain, 6-dihydroyangonin, Antares, ava pepper, ava pepper shrub, ava root, awa, bornyl cinnamate, cavain, flavokavines A and B, gea, gi, intoxicating long pepper, intoxicating pepper, kao, kavakava, kava kava extract LI 140, kava kava rhizome, kavapiper, kavarod, kava root, kavasporal forte, kavain, kave-kave, kawa, kawa kawa, kawa pepper, Kawa Pfeffer, kew, Macropiper latifolium, malohu, maluk, maori kava, meruk, milik, pepe kava, Piper methysticum, pipermethystine, piperis methystici rhizoma, Rauschpfeffer, rhizoma piperis methystici, sakau, sakua, tonga, yagona, yangona, yaqona.

Background

Kava beverages, made from dried roots of the shrub Piper methysticum, have been used ceremonially and socially in the South Pacific for hundreds of years, and in Europe since the 1700s.

Several well-conducted human studies have demonstrated kava's efficacy in the treatment of anxiety, with effects observed after as few as one to two doses, and progressive improvements over one to four weeks. Preliminary evidence suggests possible equivalence to benzodiazepines.

Many experts believe that kava is neither sedating nor tolerance-forming in recommended doses. Some trials report occasional mild sedation, although preliminary data from small studies suggest lack of neurological-psychological impairment.

There is growing concern regarding the potential for liver toxicity from kava. Multiple cases of liver damage have been reported in Europe, including hepatitis, cirrhosis, and liver failure. Kava has been removed from shelves in several countries due to these safety concerns. The United States Food and Drug Administration (FDA) has issued warnings to consumers and physicians. It is not clear what dose or duration of use is correlated with the risk of liver damage. The quality of these case reports has been variable; several are vague, describe use of products that do not actually list kava as an ingredient, or include patients who also ingest large quantities of alcohol. Nonetheless, caution is warranted.

Chronic or heavy use of kava has also been associated with cases of neurotoxicity, pulmonary hypertension, and dermatologic changes. Most human trials have been shorter than two months, with the longest study being six months in duration.

Evidence

DISCLAIMER: These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Anxiety : Human studies have found at least moderate benefit of kava in the treatment of anxiety, and preliminary evidence suggests that kava may be equivalent to benzodiazepine drugs such as diazepam (Valium®). Kava's effects were reported to be similar to the prescription drug buspirone (Buspar®) used for Generalized Anxiety Disorder (GAD) in one study. However, there is concern regarding kava's potential toxicity, based on multiple reports of liver damage in Europe and a number of cases in the U.S., including hepatitis, cirrhosis, and liver failure. The US FDA has issued warnings to consumers and physicians. Many products have been pulled from the market. Natural Standard has collaborated with the World Health Organization (WHO) to prepare a detailed report of kava and associated adverse effects, which will be published soon.
Grade: A

Stress: Early study results suggest that kava and valerian may be beneficial to health by reducing physiological reactivity during stressful situations and stress induced insomnia. Further research is needed to confirm these results.
Grade: C

Parkinson's disease: Kava has been shown to increase 'off' periods in Parkinson patients taking levodopa and can cause a semicomatose state when given with alprazolam. Therefore, it is not recommended.
Grade: D