Plant Part Used
Root/Rhizome
Introduction
Kava has been used for centuries by natives of the South Pacific. Much like coffee or tea in Western cultures, kava occupies a prominent position in the social, ceremonial, and daily life of Pacific islanders. In Europe, kava has long been used as a safe, effective treatment for mild anxiety, nervous tension, muscular tension and mild insomnia.
Note: Kava is no longer available in Canada due to regulations by Health Canada.
Interactions and Depletions
Interactions
- Sedative and hypnotic medications
- alprazolam
- Antidepressants
- OTC products causing drowsiness
- Alcoholic beverages
Dosage Info
Dosage Range
100-250mg (standardized extract), 1-3 times a day for anxiety; single dose of 250-300mg (standardized extract) before bedtime for insomnia.
Tincture: 30 drops with water 3 times daily. (1)
Infusion: take ½ cup twice daily. (2)
Most Common Dosage
100mg (standardized extract), 3 times a day as needed for anxiety; 250mg (standardized extract) at bedtime for insomnia.
Tincture: 30 drops with water 3 times daily.
Infusion: take ½ cup twice daily.
Standardization
[span class=doc]Standardization represents the complete body of information and controls that serve to enhance the batch to batch consistency of a botanical product, including but not limited to the presence of a marker compound at a defined level or within a defined range.[/span]
The most current available medical and scientific literature indicates that this dietary supplement should be standardized to 30-55% kavalactones per dose.
Reported Uses
Kava is an approved medicine in several European countries for the treatment of nervous anxiety and tension. Studies suggest that kava may be as powerful as some conventional anti-anxiety medications in controlling symptoms of anxiety and minor depression. (3) , (4) In one study involving fifty-two people suffering from anxiety, 81% of the individuals taking the kava preparation rated the treatment as “very good” or “good.” (5) The results of a study revealed that kava may be effective and safe when used for sleep disturbances associated with anxiety disorders. (6)
Other studies on the effects of kava when taken for PMS symptoms and menopausal complaints are also favorable. (7) A study of kava supplementation in forty menopausal women taking hormonal replacement therapy (HRT) who also experience anxiety was performed. (8) A greater reduction in the anxiety scores was reported in the groups treated with the HRT and kava, than patients treated with the hormones alone or with hormones and placebo.
A 50 year old man presented with jaundice and had noticed fatigue for a month and a “tanned” skin, and dark urine after consuming 3 to 4 capsules a day of a kava product for 2 months. He was hospitalized and recovered after receiving a liver transplant. (9) High usage of kava may cause abnormalities in liver function. (10) , (11) Moderate consumption of kava may cause liver damage but after abstinence of kava, liver function appeared to go back to normal. (12)
Although scientists aren’t completely clear on how kava works, many believe its key components act on the limbic system—the primitive part of the brain that controls our emotions and survival instincts. (13) It is thought that kava may promote relaxation, sleep and rest by altering the way the limbic system modulates emotional processes.
Toxicities & Precautions
Introduction
[span class=alert]Be sure to tell your pharmacist, doctor, or other health care providers about any dietary supplements you are taking. There may be a potential for interactions or side effects.[/span]
General
The United States Food and Drug Administration (FDA) has notified healthcare professionals that several cases of liver toxicity have been associated with the use of kava in Germany and Switzerland. It is unknown whether there is a link between the Kava supplements used in the United States and liver toxicity. (14) If you are experiencing a liver disorder and have used kava, please inform your healthcare professional.
This dietary supplement may cause drowsiness. Use caution when driving and performing tasks that require alertness. (15)
This dietary supplement may increase the effects of alcohol. (16)
Health Conditions
If you have Parkinson’s disease talk to your doctor before taking this dietary supplement. (17) Do not use kava if you have any gall bladder or liver problems including cirrhosis or hepatitis. (18)
Side Effects
Side effects are possible with any dietary supplement. In dosages 10 times greater than normal use, such as in tea form, this dietary supplement may cause skin irritation and rash-like symptoms. (19) , (20) Tell your doctor if these side effects become severe or do not go away.
Pregnancy/ Breast Feeding
This dietary supplement should not be used in pregnant women. (21)
This dietary supplement should not be used if you are breast-feeding an infant without first consulting a physician.
Age Limitations
To date, the medical literature has not reported any adverse effects specifically related to the use of this dietary supplement in children. Since young children may have undiagnosed allergies or medical conditions, this dietary supplement should not be used in children under 10 years of age unless recommended by a physician.
References
- Chavallier A. The Encyclopedia of Medicinal Plants. New York, NY: DK Publishing company; 1996.
- Chavallier A. The Encyclopedia of Medicinal Plants. New York, NY: DK Publishing company; 1996.
- View Abstract: Munte TF, et al. Effects of Oxazepam and an Extract of Kava Roots (Piper methysticum) on Event-related Potentials in a Word Recognition Task. Neuropsychobiology. 1993;27(1):46-53.
- Drug Therapy of Panic Disorders. Kava-specific Extract WS 1490 Compared to Benzodiazepines. Nervenarzt. Jan1994;65(1Supp):1-4.
- View Abstract: Scherer J. Kava-kava Extract in Anxiety Disorders: An Outpatient Observational Study. Adv Ther. 1998;15(4):261-9.
- View Abstract: Lehrl S. Clinical efficacy of kava extract WS 1490 in sleep disturbances associated with anxiety disorders. Results of a multicenter, randomized, placebo-controlled, double-blind clinical trial. J Affect Disord. Feb2004;78(2):101-10.
- View Abstract: Warnecke G. Psychosomatic Dysfunctions in the Female Climacteric. Clinical Effectiveness and Tolerance of Kava Extract WS 1490. Fortschr Med. Feb1991;109(4):119-22.
- View Abstract: De Leo V, La Marca A, Lanzetta D, et al. Assessment of the Association of Kava-Kava Extract and Hormone Replacement Therapy in the Treatment of Postmenopause Anxiety. Minerva Ginecol. Jun2000;52(6):263-7.
- Escher M, Desmeules J, Giostra E, et al. Hepatitis Associated with Kava, a Herbal Remedy for Anxiety. BMJ. Jan2001;322(7279):139.
- View Abstract: Mathews JD, Riley MD, Fejo L, Munoz E, Milns N, et al. Effects of the Heavy Usage of Kava on Physical Health: Summary of a Pilot Survey in an Aboriginal Community. Med J Aust. Jun1988;148:548-555.
- View Abstract: Strahl S, Ehret V, Dahm HH, Maier KP. Necrotizing Hepatitis after Taking Herbal Medication. Dtsch Med Wschr. 1998;123:1410-1414.
- View Abstract: Clough AR, Bailie RS, Currie B. Liver function test abnormalities in users of aqueous kava extracts. J Toxicol Clin Toxicol. 2003;41(6):821-9.
- View Abstract: Holm E, et al. The Action Profile of D,L-kavain. Cerebral Cites and Sleep-wakefulness-Rhythm in Animals. Arzneimittelforschung. Jul1991;41(7):673-83.
- “Dear Healthcare Professional” letter. The FDA Center for Food Safety and Applied Nutrition. 19 Dec 2001. Available at: http://www.fda.gov/medwatch/safety/2001/kava.htm. Accessed 20 Dec 2001.
- PDR for Herbal Medicines, 2nd ed. Montvale, NJ: Medical Economics Company; 2000:444.
- View Abstract: Jamieson DD, et al. Positive Interaction of Ethanol and Kava Resin in Mice. Clin Exp Pharmacol Physiol. Jul1990;17(7):509-14.
- Schelosky L, et al. Kava and Dopamine Antagonism. J Neurol Neurosurg Psychiatry. 1995;58(5):639-40.
- Escher M, Desmeules J, Giostra E, et al. Hepatitis Associated with Kava, a Herbal Remedy for Anxiety. BMJ. Jan2001;322(7279):139.
- Keller F, et al. A Review of the Chemistry and Pharmacogy of the Constituents of Piper methysticum. Lloydia. 1963;26:1-15.
- View Abstract: Piper methysticum (kava kava). Altern Med Rev. Dec1998;3(6):458-60.
- LaValle JB, et al. Natural Therapeutics Pocket Guide. Hudson, OH: LexiComp, Inc; 2000:466-467.
