Kava kava (Piper methysticum) has been used as a ceremonial beverage
in the Pacific Islands for thousands of years. The roots are chewed or ground
into a pulp and added to cold water. The resulting thick brew, which has been
compared to the social equivalent of wine in France, is typically offered to
guests and dignitaries visiting the Pacific Islands.
In addition to its ceremonial purposes, kava is perhaps best known for its
relaxing qualities. Kava is said to elevate mood, well-being, and contentment,
and produce a feeling of relaxation. Several studies have found that kava may be
useful in the treatment of anxiety, insomnia, and related nervous disorders.
However, new reports linking kava with severe liver damage has prompted
regulatory agencies in Europe and Canada to warn consumers of the potential
risks associated with this herb and even remove kava-containing products from
the market. Based on these and other reports in the United States, the Food and
Drug Administration (FDA) issued a consumer advisory in March of 2002 regarding
the "rare," but potential risk of liver failure associated with kava-containing
products. Be sure to visit the
Precautions section for further
information about the potential dangers associated with kava.
Due to these potential dangers, kava should be used only under the guidance
of a qualified healthcare practitioner. Kava has been extensively studied,
however, and evidence suggests that (under proper supervision) it may be helpful
for the following health problems:
Anxiety In a recent review of seven scientific studies,
researchers concluded that kava extract is significantly more effective than
placebo in treating anxiety. One study found that kava substantially improved
symptoms after only one week of treatment. Results of clinical studies and the
experiences of people using kava suggest that this herb may be as effective as
certain anti-depressants and anti-anxiety medications. In fact, according to one
recent study, kava and diazepam (a medication frequently used for anxiety) cause
matching changes in brain wave activity, suggesting that they may work very
similarly to calm the mind.
Some experts suggest that kava be considered for use when anxiety and/or
stress accompany certain medical illnesses. For example, such feelings are not
uncommon when being treated for cancer. In one recent survey, as many as 25% of
prostate cancer patients felt depressed or anxious. The authors of this
particular survey suggested that kava be considered to help relieve the feelings
of such men with prostate cancer.
Insomnia Short-term studies suggest that kava is effective for
insomnia, particularly in terms of improving sleep quality and decreasing the
amount of time needed to fall asleep.
Other In addition to its anxiety-reducing (anxiolytic) and
sedative properties, active compounds in kava are reputed to help prevent
seizures and relieve muscle spasms. Although kava has not been studied for these
purposes, some professional herbalists may recommend this herb to help relieve
these and related health problems.
Kava root (which is used in medicinal preparations) comes from a tall shrub
that grows in the islands of the Pacific Ocean. This shrub produces large,
green, heart-shaped leaves that grow thickly on the branches. Long, slender
flowers grow where the branches meet the stems. The roots look like bundles of
woody, hairy branches.
What's It Made Of?
The main active ingredients in kava root are called kava pyrones (or kava
lactones). The primary kava pyrones (including kawain and methysticum) have been
extensively studied in laboratory and animal studies. These substances have been
found to reduce convulsions, promote sleep, and relax muscles in animals. They
also have pain-relieving properties, which explains why chewing kava root tends
to cause a temporary numbness and tingling sensation on the tongue.
In some parts of the world, whole kava roots are chewed for their medicinal
value. Kava is also available in liquid form, as tinctures or extracts, and
powdered or crushed in capsules or tablets.
How to Take It
It is important to note that some people have developed severe liver damage,
even liver failure, after ingesting kava. See
Precautions section for more details.
Under no circumstances should this herb be taken without the supervision of a
qualified healthcare practitioner.
Pediatric There are no known scientific reports on the
pediatric use of kava. Therefore, it is not currently recommended for
Adult If your health care provider has recommended kava, make
sure you read the label to look for kava products that are standardized to
contain a 70% kava lactone content.
For the relief of anxiety and insomnia, and to reduce stress, follow your
provider's instructions. A commonly recommended kava dose is 2.0 to 4.0 grams as
a decoction (a preparation made by boiling down the herb in water) up to three
times daily. Another typical dose is 60 to 600 milligrams kava lactones daily of
Length of treatment varies.
It may take four weeks before you notice improvement. Kava should not be
taken for more than three months.
The use of herbs is a time-honored approach to strengthening the body and
treating disease. Herbs, however, contain active substances that can trigger
side effects and interact with other herbs, supplements, or medications. For
these reasons, herbs should be taken with care, under the supervision of a
practitioner knowledgeable in the field of botanical medicine. This is
particularly true for kava, given its potentially serious side effects.
In recent years, several reports in the United States and abroad have linked
kava ingestion with severe liver problems. Kava-containing products have been
associated with at least 25 reports of liver-related injuries (including
hepatitis, cirrhosis, and liver failure). In one case report, a 50-year-old man
developed hepatitis after taking three to four kava extracts daily for two
months. His condition quickly deteriorated and a liver transplant became
Liver-related risks associated with the use of kava have prompted regulatory
agencies in other countries, including those in Germany, Switzerland, France,
Canada, and the United Kingdom, to warn consumers about the potential risks
associated with kava use and to remove kava-containing products from the
Largely driven by the policies of these other countries as well as reports of
adverse effects in the United States, the FDA issued an advisory in March of
2002 regarding the "rare," but potential risk of liver failure associated with
kava-containing products. The advisory cautions individuals with liver disease
or liver problems as well as those taking products (medications, herbs, or
supplements) that affect the liver, to consult a physician before taking
kava-containing products. If you have taken kava and are experiencing symptoms
of liver damage (such as yellow skin [jaundice], fatigue, abdominal pain, loss
of appetite, nausea, vomiting, and joint pain), seek immediate medical
Other side effects associated with kava appear to be mild and infrequent.
Some reported adverse effects include allergic skin reactions (such as contact
dermatitis), dizziness, drowsiness, restlessness, stomach upset, and tremors.
Long term use at high doses may cause flaky, dry, and yellowish discoloration of
the skin, hair loss (alopecia), partial loss of hearing, and loss of appetite.
Like alcohol, kava may also have intoxicating effects and should not be taken
before driving. In addition, when taken together with kava, alcohol increases
the risk of toxicity from this herb.
Pregnant or breastfeeding women should not take kava. Those undergoing
surgery should also not take this herb as it may interfere with drugs used to
induce anesthesia and prolong the effect of anesthesia. Kava should be stopped
at least 24 hours prior to the scheduled surgery.
If you are currently being treated with any of the following medications, you
should not use kava without first talking to your healthcare provider:
Anticonvulsants Kava may exaggerate the effects of medications
used to treat seizures.
Central Nervous System (CNS) depressants Kava may enhance the
effects of CNS depressants such as benzodiazepines used for sleep disturbances
or anxiety (particularly alprazolam) and barbiturates used for sleep disorders
and seizures (such as pentobarbital). In fact, there has been one report of
someone going into a coma from the combination of kava and alprazolam.
Antipsychotic medications Kava may increase the risk of
unpleasant side effects associated with phenothiazine medications (often used
for the treatment of schizophrenia), such as chlorpromazine and promethazine.
Levodopa There has been at least one report that kava may
reduce the effectiveness of levodopa, a medication used to treat Parkinson's
disease. Therefore, you should not take this herb if you are taking any
medications containing levodopa.
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Review Date: April 2002
Reviewed By: Participants in the review process include: Jacqueline A. Hart, MD,
Department of Internal Medicine, Newton-Wellesley Hospital, Harvard University
and Senior Medical Editor Integrative Medicine, Boston, MA; Gary Kracoff, RPh
(Pediatric Dosing section February 2001), Johnson Drugs, Natick, MA; Sherif H.
Osman, MD (March 1999), President, Medical Staff Harford Memorial Hospital,
Falston General Hospital, Bel Air, MD; Steven Ottariono, RPh, Veteran's
Administrative Hospital, Londonderry, NH; David Winston (March 1999), Herbalist,
Herbalist and Alchemist, Inc., Washington, NJ; Tom Wolfe, P.AHG (March 1999),
Smile Herb Shop, College Park, MD. All interaction sections have also been
reviewed by a team of experts including Joseph Lamb, MD (July 2000), The
Integrative Medicine Works, Alexandria, VA;Enrico Liva, ND, RPh (August 2000),
Vital Nutrients, Middletown, CT; Brian T Sanderoff, PD, BS in Pharmacy (March
2000), Clinical Assistant Professor, University of Maryland School of Pharmacy;
President, Your Prescription for Health, Owings Mills, MD; R. Lynn Shumake, PD
(March 2000), Director, Alternative Medicine Apothecary, Blue Mountain
Apothecary & Healing Arts, University of Maryland Medical Center, Glenwood,
MD; Ira Zunin, MD, MPH, MBA (July 2000), President and Chairman, Hawaii State
Consortium for Integrative Medicine, Honolulu,
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regarding dosage, precautions, warnings, interactions, and contraindications
before administering any drug, herb, or supplement discussed