Top of the page
Kava—or kava kava—is a root found on South Pacific islands. Islanders have used kava as medicine and in ceremonies for centuries.
Kava has a calming effect, producing brain wave changes similar to changes that occur with calming medicines such as diazepam (Valium, for example). Kava also can prevent convulsions and relax muscles. Although kava is not habit-forming, its effect may decrease with use.
Traditionally prepared as a tea, kava root is also available as a natural health product in powder and tincture (extract in alcohol) forms.
Kava's calming effect may relieve anxiety, restlessness, sleeplessness, and stress-related symptoms such as muscle tension or spasm. Kava may also relieve pain.
When taken for anxiety or stress, kava does not interfere with mental sharpness. When taken for sleep problems, kava promotes deep sleep without affecting restful REM sleep.
Kava may be used instead of prescription anti-anxiety drugs, such as benzodiazepines and tricyclic antidepressants. Kava should never be taken with these prescription drugs.
Kava may have severe side effects and should not be used by everyone. Kava has caused liver failure in previously healthy people. You should not use kava for longer than 3 months without consulting your doctor.
Before you use kava, consider that it:
Long-term kava use may result in:
Reports from Germany and Switzerland about kava causing serious liver problems have led to the recent removal of these products from shelves in Britain. Other countries have advised consumers to avoid using kava until further information is available.
In the United States, the FDA advises people who have liver disease or liver problems, or people who are taking medicines that can affect the liver, to consult a doctor or pharmacist before using products that contain kava. People who use a natural health product that contains kava and experience signs of illness should consult a doctor. Symptoms of serious liver disease include brown urine as well as yellowing of the skin or of the whites of the eyes. Other symptoms of liver disease may include nausea, vomiting, light-coloured stools, unusual tiredness, weakness, stomach or abdominal pain, and loss of appetite.
The Natural and Non-Prescription Health Products Directorate (NNHPD), within the Health Products and Food Branch of Health Canada, regulates natural health products in Canada. Natural health products, including kava, must be reviewed and approved by the NNHPD before they can be sold in Canada. Health Canada has not licensed any kava products for sale in Canada.
Always tell your doctor if you are using a natural health product or if you are thinking about combining a natural health product with your conventional medical treatment. It may not be safe to forgo your conventional medical treatment and rely only on a natural health product. This is especially important for women who are pregnant or breastfeeding.
When using natural health products, keep in mind the following:
Current as of: March 17, 2021
Author: Healthwise Staff
Medical Review:Adam Husney MD - Family Medicine
To learn more about Healthwise, visit Healthwise.org.
© 1995-2021 Healthwise, Incorporated. Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.