Kava instead of alcohol: what the research says

2024-01-11 · 6 min read

By the kava.fyi editorial team · Last updated: 11 January 2024

After a hard day, many people reach for a glass of wine or a beer: to unwind, fall asleep more easily, talk more freely. Kava, the traditional drink made from the root of the intoxicating pepper (Piper methysticum), is sometimes recommended in exactly the same situations. Instead of marketing slogans, here we set out what reliable sources say about both substances: WHO and FAO reports, a Cochrane review and clinical trials. This article is for information only and does not replace medical advice. Kava is also not a treatment for alcohol dependence.

Relaxation: the same receptor, different consequences

Alcohol and kava both act, among other things, on GABA-A receptors, the nervous system's main "brake". That is largely where the similarities end.

According to a review by Smith and Randall (2012), a single dose of alcohol has an anti-anxiety effect because it increases GABA activity. Chronic dependence, however, leads to an overall GABA deficit, which cancels out this effect and can itself trigger anxiety. Periods of withdrawal additionally overstimulate the limbic and noradrenergic systems, both of which are involved in the onset of panic attacks.

Kava's effects are due to kavalactones. Kavain, the main one, is a positive allosteric modulator of the GABA-A receptor: it strengthens the receptor's response to GABA, but does not act through the classic benzodiazepine binding site (Chua et al., 2016). Clinical trials comparing kava with oxazepam recorded no cases of dependence or withdrawal symptoms at the doses and observation periods used (Soares et al., 2022). We describe the mechanism in more detail in the article kava and GABA.

Anxiety: alcohol worsens it, kava eases it in clinical trials

The Cochrane review (Pittler and Ernst, 2003) covered 11 randomised trials involving a total of 645 people. A meta-analysis of six of them showed a significant reduction in the Hamilton anxiety scale score in people taking kava extract compared with placebo (weighted mean difference of 5.0 points). Adverse effects were described as mild, transient and rare. The authors judged kava relatively safe for short-term use, from 1 to 24 weeks, while noting that data on long-term safety were insufficient.

The protocol for the Australian K-GAD study (Savage et al., 2015) sums up this state of knowledge concisely: kava is a non-addictive, non-sedating anxiolytic with potential in generalised anxiety disorder. It is worth remembering that most clinical trials involved standardised extracts, not the traditional water-based drink.

A clear head: what a New Zealand study found

The most telling study of cognitive function after kava was carried out by a team led by Dr Apo Aporosa at the University of Waikato. Twenty regular consumers each drank 3.6 litres of kava over six hours, while a control group of 19 non-drinkers was also tested. A Brain Gauge device was used to measure six functions: focus, accuracy, temporal order judgement, time perception, plasticity and fatigue.

Impairment was found in only one of the six measures: temporal order judgement, that is, the ability to arrange events in sequence, needed for example when checking for hazards before a junction.
The other five functions were unaffected.
The results were published in the Journal of Ethnopharmacology in 2022.

The practical conclusion is that you should not get behind the wheel after large amounts of kava, just as after alcohol. There is, however, no question of it "dulling the mind". The 2016 FAO/WHO report states that the available evidence supports the conclusion that kava does not affect cognitive function, although one study found an improvement in visual attention (Thompson et al., 2004) and another a decline (Cairney et al., 2003). A systematic review by LaPorte et al. (2011), cited in this report, found no reproducible negative effects of kava on cognition. We write about how kava works in practice in a separate review of its effects.

Health: alcohol has no safe dose, kava comes with caveats

The WHO data are unambiguous. In 2019, alcohol caused about 2.6 million deaths worldwide. About 400 million people, or 7 percent of the population aged 15 and over, were living with alcohol use disorders, and 209 million with dependence. The WHO stresses that there is no form of drinking free of risk. The International Agency for Research on Cancer classes alcohol as a Group 1 carcinogen, the same category as asbestos and tobacco, and alcohol causes at least seven types of cancer. In 2019 it was attributed with 401,000 cancer deaths.

Kava has a different profile, but it is not free of controversy. According to the FAO/WHO report (2016), the kava drink has been consumed in the Pacific for more than 2,000 years, and there are very few published reports of health harm from traditional consumption. Clinical trials of water-based extracts have likewise shown no adverse effects. On the other hand, the German agency BfArM banned kava products in 2002 on the basis of 41 reports of liver damage in Germany and 73 worldwide (Soares et al., 2022). The 2007 WHO assessment, summarised in the FAO/WHO report, found that there is significant concern about a causal link between kava products and hepatotoxicity, higher for organic extracts, and that kava products have a strong tendency to interact with medications. Psychiatrist James Lake advises against kava for people who misuse alcohol or take high doses of sedatives. We discuss this topic separately in the article kava and the liver.

Sleep: why a "nightcap" does not work

Alcohol makes you drowsy, but it disrupts sleep. As Stein and Friedmann (2005) write, alcohol's suppression of REM sleep was already observed back in the 1960s. Once blood alcohol concentration falls to near zero, after 2 to 3 hours a rebound effect sets in: arousal increases and the second half of the night becomes fragmented. Tolerance to the sedative effect develops after 3 to 7 days of drinking.

In traditional Pacific communities, kava is used, among other purposes, to support sleep and reduce anxiety (Aporosa et al., 2025). Solid polysomnographic research on the traditional drink is still lacking; we summarise the current state of it in the article kava and sleep.

Hangover and conversation

A kava hangover depends on the cultivar. "Two-day" (tudei) cultivars cause nausea and headaches, and their effect can last up to two days (Soares et al., 2022). Noble cultivars, the only ones permitted under Vanuatu's 2002 Kava Act, give, according to Dr Vincent Lebot, a quick and pronounced relaxing effect that wears off by dinner time. A list of cultivars can be found in the cultivar atlas.

Finally, conversation. In Pacific cultures, kava accompanies talanoa, open discussion, and is sometimes used in restorative justice processes and conflict resolution. The authors of a paper in Frontiers in Psychology (2025) note that even after large amounts of kava, reason and awareness remain intact, and the drink does not provoke emotional or aggressive behaviour. This is the most factual answer to the question of how kava differs from alcohol among friends.