What is kava?

Kava—or kava kava—is a root found on islands in the western Pacific Ocean. Traditionally prepared as a tea, kava root is also available in other forms. These include dietary supplements and liquid or powder extracts.

Kava may cause mild side effects, such as digestive problems, headaches, or dizziness. Over time, with high doses, it can cause dry, flaky, or yellow skin. Taking kava can also cause serious side effects, such as liver failure and death.

Kava can also affect how fast a person reacts, making it unsafe to drive or use heavy machinery.

Because of the side effects it can cause, kava isn't available in some countries.

The FDA does not regulate dietary supplements in the same way it regulates medicine. A dietary supplement can be sold with limited or no research on how well it works.

Always tell your doctor if you are using a dietary supplement or if you are thinking about combining a dietary supplement with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on a dietary supplement. This is especially important if you are pregnant or breastfeeding.

When using dietary supplements, keep in mind the following:

• Like conventional medicines, dietary supplements may cause side effects, trigger allergic reactions, or interact with prescription and nonprescription medicines or other supplements you might be taking. A side effect or interaction with another medicine or supplement may make other health conditions worse.
• The way dietary supplements are manufactured may not be standardized. Because of this, how well they work or any side effects they cause may differ among brands or even within different lots of the same brand. The form of supplement that you buy in health food or grocery stores may not be the same as the form used in research.
• Other than for vitamins and minerals, the long-term effects of most dietary supplements are not known.

Kava is used by some people for anxiety, sleeplessness, or other health problems. Taking kava may reduce anxiety. But so far there isn't clear proof from science that it helps with other health problems.