‘Kava,’ or ‘kava kava,’ (Piper methysticum) is a psychoactive plant endemic to the Pacific Islands [1]. The indigenous use of kava, typically through mastication or as a beverage wherein the root is macerated into water or coconut water, is reported to provide anxiolytic and sedating effects [2–4]. In regions where kava is native, it has been used in religious and cultural practices, as well as medicinally [5]. While kava root is believed to have been consumed for centuries, documentation on kava use began with colonization and was recognized in Western medicine in the late 1880’s as a potential anxiolytic [1, 6].

Kavalactones are among the best studied chemical constituents of kava, with six of approximately 18 kavalactones demonstrating pharmacological activity; kavain and methysticin are typically found in the highest quantities while dihydrokawain, dihydromethysticin, yangonin, and desmethoxyyangonin are found in smaller quantities [3, 7, 8]. Minor constituents include amino acids, minerals (potassium, sodium), and flavokavins (A, B and C) [9]. Although the exact mechanisms of kava’s effects in humans are not perfectly elucidated some putative mechanisms by which kavalactones may mediate pharmacological effects include GABA_A receptor-enhancing mechanisms, blockade of sodium and calcium channels, as well as blockade of reuptake of norepinephrine and dopamine, and MAO-B inhibition [9–12]. Kavain and dihydrokavain in particular are associated with reported anxiolytic activity [12–14]. In clinical studies examining kava’s anxiolytic effects between 1989 and 2004, daily doses of kavalactones administered as part of the investigation ranged from 60 to 240 mg, with the longest duration of use 210 mg of kavalactones for 24 weeks [15, 16]. Across these studies, the average kavalactones per day was approximately 158 mg.

Some adverse effects have been reported or observed – both indigenously and more recently in the United States – taking kava for prolonged periods or large amounts. This includes hepatotoxicity and dermopathy, with the former appearing most frequently [2, 17–20]. Although there is a record of historical use for kava in regions where it is indigenous, such use does not translate to the United States where kava preparations are relatively novel and often consumed alongside myriad other psychoactive substances [14, 21–24].

In recent years, kava products have proliferated in the United States. Some kava products contain low amounts of kavalactones are sold as dietary supplements typically in capsule form at health and wellness stores or high-end groceries and commercial tea bags may advertise kava as an relaxing constituent [25]. Parallel to this, products containing concentrated amounts of kava root extract at doses that are high relative to commercial dietary supplements containing kava sold in health and wellness stores are being sold online and in convenience stores in liquid shots or tonics, sometimes blended with other psychoactive botanicals (e.g., CBD, kratom) [26, 27]. Kava is also prepared into drinks at ethnobotanical tea bars selling kava and kratom [1, 6, 28–30].

Kava is not controlled or scheduled under the Controlled Substances Act by the Drug Enforcement Administration and may be considered by the U.S. Food and Drug Administration (FDA) to be and “old dietary ingredient,” meaning that kava could be sold in certain forms as a dietary supplement [31, 32]. Both FDA and the Centers for Disease Control and Prevention have released reports and consumer advisories, warning those who consume kava of the potential adverse effects, namely those related to liver injury and FDA has not evaluated efficacy for any reported kava effects [28, 33, 34]. Products containing kava marketed as a dietary ingredient or supplement are expected to have a reasonable basis of safety for their indicated use. Despite the increased presence of kava in regions where it is not indigenous, its use remains underexplored.

Accordingly, we sought to characterize the attributes of adults with a history of kava use. Among this group we aimed to identify kava consumption behaviors, other substances consumed contemporaneous to kava, use motivations, and conceptualizations of kava. We also explored how kava use is experienced across settings, including ethnobotanical tea bars that serve kava and other psychoactive botanical-derived beverages (e.g., kratom), and to better understand general perceptions and attitudes of kava use. Other findings from this project related to substance use disorder for kava are presented elsewhere [24].