The purpose of this site is to collect lab research by medical doctors about herbs that are proven to treat illnesses and counter the false attacks on herbs by the medical industry and false claims by alternative medicine. I let the science tell the facts.
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Kava Date Written 2007
Author By Joe Holmes Date Revised June 21, 2009

Kava is blamed for liver damage and other problems yet actual scientific research disproves this if the dosage does not exceed 250 mg a day. See report #5 below. This is further verified by report # 2 below with a high dosage over 310 grams a week that reports problems. One gram = 1,000 mg so report #5 of 250 mg a day times 7 = 1750 which means the PUB MED research report #5 is 18% of the amount in report #2.

This means that Kava is proved safe with no side effects if the dosage does not exceed 250 mg a day or 1.7 grams a week. As a collector of research I see this problem many where the medical community bans a product because it is being over used. Too often those in the natural health or traditional medicine over use a compound. As a result Kava is banned in several countries. Not because it is bad but because too often it is over used. Too often people think if a little is good more has to be better. Herbs are strong drugs and must be respected and used in their proven safe dosages. When over use of Tylenol, Aspirin or other prescribed drugs cause problems they are never banned. The medical community is quick to ban an herb that has been used improperly and ignore the problems of altered drugs.

Again research reports 3, 4 and 5 show there are no problems with Kava if used in its proper safe dosage. Reports 1 and 2 show the problems if it is used in excess.

1. "Genus; Species: Piper methysticum CAM Type: biologically based. Common Names: kava kava, ‘awa (Hawaii), ‘ava (Samoa), sakua (Pohnpei), yaqona (Fiji) Introduction to Kava:

Kava is an ancient western Pacific crop related to the black pepper – both having heart-shaped leaves and flowers similar to the flower spike of the anthurium. Kava also has a peppery taste, and has long been part of religious, political and cultural life throughout the Pacific region. The drink was the beverage of choice for the South Pacific royal families. Learn more about combination herbal therapies that include nutrients and herbs like Valerian Root, St. John's Wort, Rhodiola Rosea, 5-HTP, and SAMe. Natural Alternatives for stress, occasional anxiety, mood balance, focus and sleep difficulties. Click here to learn more. It is believed to have originated in Melanesia, and grows abundantly in the sunny Polynesian islands. Drank for hundreds of years by native islanders, it was only during Captain Cook’s voyage to the Pacific in 1768-1771 that the white man first encountered the plant and its consumption in sacred ceremonies. According to his account, natives would chew or pound the root and mix it with water to produce a brownish, often bitter brew which they then consumed for its psychoactive properties. Common Uses: sleep, fatigue, asthma, urinary tract infections, anxiety, insomnia, menopausal symptoms. In the Western world, kava is used as an herbal remedy to ease symptoms of anxiety, stress and depression. The effects of drinking kava include slight tongue and lip numbing due to the contraction of blood vessels in these areas, milk talkative and euphoric behavior, calming, a sense of well-being, clear thinking and relaxed muscles. Sleep is restful and there are no after-effects the next day." (1)

2. "High doses are considered to be greater than 310 grams/week.

  • Do not use if pregnant, nursing, or being treated for depression.
  • Higher doses and long term use can lead to hypertension, reduced protein levels, blood cell abnormalities, liver damage, muscle weakness, shortness of breath, visual impairment, dizziness and dry and scaly skin.
  • Alcohol consumption increases the toxicity of the pharmacological constituents.
  • Can cause drowsiness. If this happens, lower your dosage or discontinue taking kava.
  • It is not recommended for those who intend on driving or where quick reaction time is required
  • May worsen Parkinson's disease and should not be used by individuals with Parkinson's disease.
  • Do not take if you are on any other prescription medication.
  • Do not allow children to take kava kava.
  • Some doctors have cautioned against use when driving.
  • Ask a healthcare professional before use if you have or have had liver problems, frequently use alcoholic beverages, or are taking any medication. Stop use and see a doctor if you develop symptoms that may signal liver problems (e.g., unexplained fatigue, abdominal pain, loss of appetite, fever, vomiting, dark urine, pale stools, yellow eyes or skin). (2)

3. "Kava is a tranquilizer primarily consumed to relax without disrupting mental clarity. Its active ingredients are called kavalactones. In some parts of the Western World, kava extract is marketed as herbal medicine against stress, insomnia, and anxiety. A Cochrane Collaboration systematic review of its evidence concluded that it was likely to be more effective than placebo at treating short-term social anxiety.[1] Safety concerns have been raised over liver toxicity, although research indicates that this may be largely due to the use of stems and leaves in supplements, which were not used indigenously.[2][3]" (3)

4. "Kava hepatotoxicity: Regulatory data selection and causality assessment. Teschke R, Wolff A. Department of Internal Medicine II, Division of Gastroenterology and Hepatology, Klinikum Hanau, Teaching Hospital of the Johann Wolfgang Goethe-University, Frankfurt/Main, Germany.

BACKGROUND: Kava hepatotoxicity in 20 patients from Germany has been debated worldwide following a regulatory ad hoc causality assessment and ban of kava, an anxiolytic herbal remedy obtained from the rhizome of Piper methysticum Forster. AIMS: We assessed causality with a quantitative structured causality analysis in all 20 cases of patients with liver disease, presented by the German regulatory agency that assumed a causal relationship with the use of kava extracts. METHODS: The quantitative scale of CIOMS (Council for International Organizations of Medical Sciences) in its updated form was employed for causality assessment and quality evaluation of the regulatory data presentation. RESULTS: The regulatory information is scattered and selective, and items essential for causality assessment, such as exclusion of kava independent causes, were not, or only marginally, considered by the regulator. Quantitative causality assessment for kava was possible (n=2), unlikely (n=12), or excluded (n=6), showing no concordance with the regulatory ad hoc causality evaluation. CONCLUSION: The regulatory data regarding kava hepatotoxicity is selective and of low quality, not supportive of the regulatory proposed causality; but instead, is an explanation of the overall causality discussions of kava hepatotoxicity. We are proposing that the regulatory agency reports data in full length and reevaluates causality. PMID: 19477698 (4) Note by webmaster. Hepatotoxicity means liver damage. This research report and others on PUB MED PMID: 19501269 indicate that the common assumption of Kava causing liver damage may exist but is not the risk being reported and may be from other compounds.

5. "The Kava Anxiety Depression Spectrum Study (KADSS): a randomized, placebo-controlled crossover trial using an aqueous extract of Piper methysticum. Sarris J, Kavanagh DJ, Byrne G, Bone KM, Adams J, Deed G. School of Medicine, The University of Queensland, Brisbane, Australia,

RATIONALE: Piper methysticum (Kava) has been withdrawn in European, British, and Canadian markets due to concerns over hepatotoxic reactions. The WHO recently recommended research into "aqueous" extracts of Kava. OBJECTIVE: The objective of this study was to conduct the first documented human clinical trial assessing the anxiolytic and antidepressant efficacy of an aqueous extract of Kava. DESIGN AND PARTICIPANTS: The Kava Anxiety Depression Spectrum Study was a 3-week placebo-controlled, double-blind crossover trial that recruited 60 adult participants with 1 month or more of elevated generalized anxiety. Five Kava tablets per day were prescribed containing 250 mg of kavalactones/day. RESULTS: The aqueous extract of Kava reduced participants' Hamilton Anxiety Scale score in the first controlled phase by -9.9 (CI = 7.1, 12.7) vs. -0.8 (CI = -2.7, 4.3) for placebo and in the second controlled phase by -10.3 (CI = 5.8, 14.7) vs. +3.3 (CI = -6.8, 0.2). The pooled effect of Kava vs. placebo across phases was highly significant (p < 0.0001), with a substantial effect size (d = 2.24, eta(2)(p)). Pooled analyses also revealed highly significant relative reductions in Beck Anxiety Inventory and Montgomery-Asberg Depression Rating Scale scores. The aqueous extract was found to be safe, with no serious adverse effects and no clinical hepatotoxicity. CONCLUSIONS: The aqueous Kava preparation produced significant anxiolytic and antidepressant activity and raised no safety concerns at the dose and duration studied. Kava appears equally effective in cases where anxiety is accompanied by depression. This should encourage further study and consideration of globally reintroducing aqueous rootstock extracts of Kava for the management of anxiety. PMID: 19430766 (5) Webmaster note: Kava in this report with a human double blind test shows a dosage of 250 mg of kavalactones/day has no adverse effects and positivally improved depression symptoms in the test subjects.

1 Insight Journal
2 Personal Health Zone
3 Wikipedia
4 PMID: 19477698
5 PMID: 19430766


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