Kava is used in the South Pacific Islands for relaxation and socialization. It is available in the US as a dietary supplement, and was used in Europe in the 1990s to treat mild to moderate anxiety. Some clinical trials suggested kava's efficacy in treating generalized anxiety disorder (GAD), although a recent meta-analysis was inconclusive. While the mechanisms behind kava's anxiolytic activity are not well-established, its clinical use shows no signs of addiction or withdrawal. Kava thus is a promising and potentially novel anxiolytic with a unique mechanism of action. Although kava has been extensively consumed by humans for centuries, its pharmacokinetics have never been characterized in humans. Such knowledge is essential for its future studies of its anxiolytic potential and dose optimization. This study will characterize kava pharmacokinetics, which will set a solid foundation for its future clinical development. To establish kava pharmacokinetics, each participant will take three 75 mg kava capsules in a single dose and the absorption, distribution, metabolism and excretion of kava will be assessed, corresponding to the pharmacokinetic curve. Serum liver biochemistries will then be monitored for up to three months to test liver function response to kava.
