Kava Is Natural and Legal, But Is It Safe?

Kava — also referred to as kava kava, Yaqona, 'awa, ava, sakau, Tonga and countless other names — is the Tongan word given for the plant Piper methysticum. This scientific name actually translates to "intoxicating pepper." Kava is a tall-growing perennial shrub native to the Pacific islands, including Hawaii. It's harvested for its roots, which contain the pharmacologically active compounds known as kavalactones. The term "kava" also refers to the psychoactive beverage made from the roots.

Kava, the beverage, is a folk medicine that's been used for centuries by South Pacific islanders for social and ceremonial uses, says Zhaoping Li, M.D., professor of medicine and chief of the division of clinical nutrition at the University of California, Los Angeles. Indigenous people of the Pacific islands offer kava as a sign of respect and a means of strengthening social and familial ties, particularly among men. It's also used to assist in the communication with spirits and for medical purposes. Pacific islanders have placed certain restrictions on the use of kava that limit who can drink it and when it can be consumed, which helps promote the safe and controlled use.

The traditional preparation involves chewing or grinding the root until it produces a cloudy, milky pulp, and then soaking it in water to steep. The water is then strained out and served in a half coconut shell, then swallowed down in one gulp. The flavor is described as "earthy" or "like muddy water" — hardly appetizing terms. But people don't drink it for the taste.

Kavalactones do something "very interesting," Li says. "They work on a special receptor in the brain which helps to calm you down." Consuming the substance is said to have a peaceful, calming, almost euphoric effect, and is even promoted in the United States as a natural dietary supplement to tame anxiety or help you sleep.

Kava is available both online and in stores that sell dietary supplements. It's available as whole roots, powdered roots, extracts (in powder, paste or liquid form), tea bags and instant powdered drink mixes. It's also formulated as tablets or capsules and can be found in products containing a variety of herbs or vitamins, or both.

Kava tea bars are also popping up across the country, where consumers can drop in and enjoy a cup of kava brew, often flavored to make the tea more palatable.

According to a handful of studies, kava's effects actually can reduce anxiety. According to an analysis of six clinical trials evaluating the effects of kava, participants who consumed doses of 60 to 200 milligrams of kavalactones per day experienced a significant reduction in anxiety compared to participants who were given a placebo. Another meta-analysis found that three of seven clinical trials involving kava found it more effective than the placebo.

The U.S. Food and Drug Administration (FDA) has not made a determination about the efficacy of kava as an anti-anxiety agent. It's regulated by the agency as a dietary supplement under a different and more lenient set of rules than medical drugs.

"In a sense, the effects of the kavalactone compound in kava is almost like the effects of alcohol," or even anti-anxiety medication such as Xanax, Li says. The more you consume, the more powerful the effects. But it can also be difficult to know just how much of the active ingredient you are consuming, she points out. The potency of kava can vary greatly depending on the proportions of the kavalactones in the plant variety used and the method of preparation.

There is concern that, due to inconsistencies in various products, individuals may consume as much as 25 grams of kavalactones — which translates to about 125 times the daily dose in kava supplements. Instead of promoting a peaceful calm, such a kava overload can lead to intoxication, causing a lack of coordination and sleepiness. However, kava isn't generally associated with the same general confusion and delirium that occurs with high alcohol intoxication.

Regardless, the American Association of Poison Control Centers is fielding an increasing number of reports involving kava, with 88 case mentions and 48 single exposures reported in 2016, which jumped to 106 case mentions with 75 exposures the following year.

Kava is also not considered addictive, though there's not a lot of research to say that definitively, Li cautions. As previously mentioned, the "high" associated with kava is not unlike alcohol or Xanax, both of which are considered highly addictive.

There's also some evidence that commercial extract preparations of kava have been linked to serious health conditions. There are numerous cases of kava-related liver damage, including hepatitis and cirrhosis, and liver failure, which in some cases were severe or fatal. In 2002, the FDA issued an advisory warning consumers that kava-containing dietary supplements had been associated with liver-related injuries, even in young, previously healthy individuals. Other side effects associated with chronic use of kava in large quantities include dry, scaly skin or yellow skin discoloration known as kava dermopathy, tremor and abnormal body movements.

There's also concern that kava may interact with other medications, dietary supplements or alcohol, and cause serious and possibly life-threatening side effects, such as respiratory depression, which can lead to death, Li says.

Despite the health concerns, kava is not a controlled substance in the U.S., but is restricted in other countries including Australia, Canada, France, Germany, Japan, Malaysia, Norway, Poland, Singapore, South Africa, Sweden, Switzerland and the United Kingdom.