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Kava is a herb that has traditionally been drunk as a hypnotic and anxiety reducer. It has been shown effective in reducing anxiety, sometimes at a potency similar to pharmaceuticals; may be a cognitive enhancer, but not completely safe.

Our evidence-based analysis on kava features 68 unique references to scientific papers.

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Last Updated:

How to Take

Recommended dosage, active amounts, other details

When supplementing Kava, initially an extract known as WS1490 should be sought out. 300mg of this extract daily (in three divided doses of 100mg) appears to be reliable and effective for the treatment of anxiety and other cognitive issues. Doses of up to 800mg of the WS1490 extract have been tolerated for short periods of time.

Otherwise, supplementation of any product conferring 250mg collective kavalactones (the active ingredients) is used.

Although it is usually taken at multiple times throughout the day with meals, if a single dose per day is being used it tends to be used prior to sleep.

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Human Effect Matrix

Unlocked for Examine members

The Human Effect Matrix summarizes human studies to tell you what effects Kava has on your body, how much evidence there is, and how strong these effects are.

Full details are available to Examine members.
Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
grade-a Notable Very High See all 8 studies
Appears to be quite reliable and effective in treating non-psychotic anxiety, with less reliability on the topic of generalized anxiety (which lavender shows some promise for). It is possible that long-term usage of kava may have similar side-effects as long term usage of benzodiazepines (not demonstrated, but wholly logical) and most studies on kava are of a few weeks in duration without any problems.
grade-b Notable Very High See all 4 studies
The increase in well being appears to be quite large, but secondary to reducing anxiety. At least one study has noted that, in healthy persons subject to a minor stressor (testing) that kava enhanced cheerfulness
grade-c Notable - See study
The one study to measure reaction time noted an astounding decreased (approximately 40% reduction), which needs to be replicated
grade-c Minor - See study
Aggressive symptoms of anxiety have been noted to be decreased following kava ingestion, an outright reduction of anxiety (without treating anxiety) is uncertain
grade-c Minor - See study
Possibly secondary to the antianxiety effects, kava taken prior to a test is able to enhance cognition related to mood during the stressful test.
grade-c Minor Very High See 2 studies
Depressive symptoms have been reduced vicariously through reductions in anxiety; per se antidepressant effects of kava uncertain
grade-c Minor Very High See 2 studies
Sleep quality is enhanced via reducing the symptoms of anxiety which impair sleep
grade-c - Very High See 2 studies
No significant influence on liver enzymes assuming the water extract (WS1490) is being used
grade-d Minor - See study
One study has noted a reduction in blood pressure associated with kava, of minor magnitude
grade-d Minor Very High See 2 studies
Possible antistress effects of kava that requires larger studies

Studies Excluded from Consideration

  • Excluded[1] as results are confounded with St.John's wort ingestion (150mg kavalactones, 2970mcg hypericin daily)

  • Excluded due to lack of non-active control; comparative study[2]

  • Confounded with calcium supplementation[3]

  • Confounded with Hormone Replacement Therapy[4]

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Things to Note

Primary Function:

Also Known As

Piper methysticum, Kava Pepper, Ava Pepper, Kava Kava, Intoxicating Pepper, Awa, rauschpfeffer, sakau, tonga, wurzelstock, yangona

Caution Notice

Kava and Kava containing products are suspected to interact adversely with drugs and other pharmaceuticals, caution should be used when pairing Kava with other compounds

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Click here to see all 68 references.