It is consumed throughout the Pacific Ocean cultures of Polynesia, including Hawaii and Vanuatu, Melanesia, some parts of Micronesia, such as Pohnpei and Kosrae, and the Philippines.

It originally referred to Zingiber zerumbet, used to make a similar mildly psychoactive bitter drink in Austronesian rituals.

In other languages, such as Futunan, compound terms like kavakava atua refer to other species belonging to the genus Piper.

[27] Kava was historically grown only in the Pacific islands of Hawaii, Federated States of Micronesia, Vanuatu, Fiji, the Samoas, and Tonga.

Each cultivar has not only different requirements for successful cultivation, but also displays unique characteristics both in terms of its appearance and its psychoactive properties.

The Aliʻi (kings) of precolonial Hawaii coveted the Moʻi variety, which had a strong cerebral effect due to a predominant amount of the kavalactone kavain.

The reverence for Hiwa in old Hawaiʻi is evident in this portion of a chant recorded by Nathaniel Bright Emerson and quoted by E. S. Craighill and Elizabeth Green Handy: "This refers to the cup of sacramental ʻawa brewed from the strong, black ʻawa root (ʻawa hiwa), which was drunk sacramentally by the kumu hula": The day of revealing shall see what it sees: A seeing of facts, a sifting of rumors, An insight won by the black sacred 'awa, A vision like that of a god!

The Maori word kawa also means "ceremonial protocol", recalling the stylized consumption of the drug typical of Polynesian societies".

[6] Kawakawa is commonly used in Maori traditional medicine for the treatment of skin infections, wounds, and cuts, and (when prepared as a tea) for stomach upsets and other minor illnesses.

[37] However, six of them, including kavain, dihydrokavain, methysticin, dihydromethysticin, yangonin, and desmethoxyyangonin, have been determined to be responsible for about 96% of the plant's pharmacological activity.

[48] Kava is consumed in various ways throughout the Pacific Ocean cultures of Polynesia, Vanuatu, Melanesia, and some parts of Micronesia and Australia.

In Papua New Guinea, the locals in Madang province refer to their kava as waild koniak ("wild cognac" in English).

Fijians commonly share a drink called grog, made by pounding sun-dried kava root into a fine powder, straining and mixing it with cold water.

[54] In particular, it has been noted that, unlike traditional water-based preparations, products obtained with the use of organic solvents do not contain glutathione, an important liver-protecting compound.

In the context of these concerns, the World Health Organization advises against the consumption of ethanolic and acetonic kavalactone extracts, and says that "products should be developed from water-based suspensions of kava".

[58][59] Due to the importance of kava in religious rituals and the seemingly (from the Western point of view) unhygienic preparation method, its consumption was discouraged or even banned by Christian missionaries.

[6] With kava's increasing popularity, bars serving the plant in its liquid state are beginning to open up outside of the South Pacific.

[33][40][71][51] In addition to the potential for hepatotoxicity, adverse reactions from chronic use may include visual impairment, rashes or dermatitis, seizures, weight loss, and malnutrition, but there is only limited high-quality research on these possible effects.

[16][40] On the basis of research findings and long history of safe use across the South Pacific, experts recommend using water-based extractions of high-quality peeled rhizome and roots of the noble kava cultivars to minimize the potential of adverse reactions to chronic use.

[40] A few notable potential drug interactions are, but are not limited to: Long-term and heavy kava consumption is associated with a reversible skin condition known as "kava dermopathy", or kanikani (in the Fijian language), characterised by dry and scaly skin covering the palms of the hands, soles of the feet, and back.

Despite numerous studies, the mechanism that causes kava dermopathy is poorly understood "but may relate to interference with cholesterol metabolism".

[81] Preliminary analysis of kava effects in people with short-term anxiety disorders indicated a small level of improvement.

[82] Over centuries, kava has been used in the traditional medicine of the South Pacific Islands for central nervous system and peripheral effects.

[83] As noted in one literature review: "Peripherally, kava is indicated in traditional Pacific medicine for urogenital conditions (gonorrhea infections, chronic cystitis, difficulty urinating), reproductive and women's health (...), gastrointestinal upsets, respiratory ailments (asthma, coughs, and tuberculosis), skin diseases and topical wounds, and as an analgesic, with significant subtlety and nuance attending the precise strain, plant component (leaf, stem, root) and preparative method to be used".

[91] Some Pacific island states which had been benefiting from the export of kava to the pharmaceutical companies have attempted to overturn the EU ban on kava-based pharmaceutical products by invoking international trade agreements at the WTO: Fiji, Samoa, Tonga, and Vanuatu argued that the ban was imposed with insufficient evidence.

In early 2016, a court case was filed against the Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM/German Federal Institute for Drugs and Medical Devices), arguing that the new regulatory regime is too strict and not justified.

[95] In the United Kingdom, it is a criminal offence to sell, supply, or import any medicinal product containing kava for human consumption.

[97] Under the new legislation, kava is no longer listed among prohibited substances and it is therefore legal to possess, import, and consume the plant,[98] but it remains illegal to sell it within Poland for the purpose of human consumption.

The aerial parts of the plant (growing up and out of the ground), unlike the roots, contain relatively small amounts of kavalactones; instead, they contain a mildly toxic alkaloid, pipermethysticine.

[105][106] In 2002, the U.S. Food and Drug Administration issued a Consumer Advisory: "Kava-Containing Dietary Supplements May be Associated with Severe Liver Injury".