ByLaura Shane-McWhorter, PharmD, University of Utah College of Pharmacy
Reviewed/Revised Mar 2024

Kava comes from the root of a shrub that grows in the South Pacific. It is ingested as a tea or in capsule form. The active ingredients are thought to be kavalactones.

(See also Overview of Dietary Supplements.)

Claims for Kava

People use kava mostly as a sedative, to reduce anxiety, restlessness, or stress, and to aid sleep. Some people use kava for asthma, menopausal symptoms, and urinary tract infections.

Evidence for Kava

Some scientific evidence supports use of kava to reduce anxiety and as a sleep aid.

Side Effects of Kava

Some people in both Europe and the United States who have taken kava developed liver toxicity (including liver failure). Thus, the Food and Drug Administration (FDA) has required a warning label on kava products, and safety is under continuing surveillance. Some researchers believe the liver toxicity may be due to inappropriate preparation or poor quality raw material contaminated with mold that contains liver toxins.

When kava is prepared traditionally (as tea) and used in high doses or over long periods of time, a scaly rash (kava dermopathy), vision problems, changes in blood (such as an increased number of red blood cells), and changes in movement disorders (such as worsening of Parkinson disease) may occur.

Kava should be stopped at least 2 weeks before surgery to clear it from the system because kava can cause excessive sedation when anesthetics or other sedatives are given.

Drug Interactions with Kava

Kava may prolong the effect of other sedatives (such as barbiturates or alcohol) and affect driving or other activities requiring alertness.

Kava may cause liver damage if taken with hepatotoxins (medications that are toxic to the liver).

Kava may intensify the effect of anesthetics.

Recommendations for Kava

Kava use is not recommended. Kava can have serious side effects. There are safer and probably more effective methods, medications, or alternative treatments for relieving anxiety and promoting sleep. People who take kava should be counseled to discontinue its use 2 weeks before surgery.

Pregnant women and women who are breastfeeding should avoid kava; kava can negatively effect the uterus and also may pass into breast milk.

More Information

The following English-language resource may be useful. Please note that THE MANUAL is not responsible for the content of this resource.

  1. National Institutes of Health's National Center for Complementary and Integrative Health: Kava

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