This information describes the common uses of Kava, how it works, and its possible side effects.
Tell your healthcare providers about any dietary supplements you’re taking, such as herbs, vitamins, minerals, and natural or home remedies. This will help them manage your care and keep you safe.
What is it?
Studies on kava for anxiety are mixed, and liver toxicity is a major concern.
The active compounds in kava are called kavalactones. In studies in animals and humans, these compounds appeared to provide pain relief and act as muscle relaxants and anticonvulsants.
Although data suggest it may be helpful for anxiety, a recent well-designed study did not find benefit for those with diagnosed anxiety disorder.
Kava is known to cause liver damage.
What are the potential uses and benefits?
- To treat anxiety and stress
Studies on potential benefits are mixed and a recent study did not find benefit for those with diagnosed anxiety disorder. In addition, the risk of liver damage from kava use outweighs benefits. - To treat insomnia
No scientific evidence supports this use.
What are the side effects?
- Headache
- Impaired reflexes or judgment
- Visual disturbances
- Sedation
- Restlessness
- Tremor
- Hangover effect
Case reports
- Liver damage (rare): Immediately inform your doctor if you have yellowish discoloration of the skin, eyes, fingernails or toenails, nausea, or vomiting.
- Low blood platelets and white blood cells with overdose or long-term use. Can also can cause dry flaking skin, respiratory problems, and hearing impairment. Inform your doctor immediately if you have any of these symptoms.
- Skin eruptions with itching and burning: A few cases were associated with using kava tea or supplements.
- Impaired driving behavior and signs of intoxication: Associated with kava use.
What else do I need to know?
Patient Warnings:
- Kava may cause liver damage. The British, French, German, and Swiss governments have requested that kava be removed from the market. The Canadian government has warned consumers not to use kava-containing products.
- Overdose or long-term use can cause low blood platelets and white blood cells, dry flaking skin known as kava dermopathy, respiratory problems, and hearing impairment. Inform your doctor immediately if you have any of these symptoms.
- Kava may impair your ability to drive or operate heavy machinery.
Do Not Take if:
- You have liver or kidney problems: Kava may worsen them.
- You are taking benzodiazepines such as Ativan®, Xanax®, Serax®, Valium®, or Tranxene®: Kava may increase sedation.
- You drink alcoholic beverages: Kava may increase sedation. Avoid using kava and alcohol at the same time.
- You are taking barbiturates: In theory, kava may increase sedation and muscle-relaxant effects.
- You take sedatives: In theory, kava may increase sedation.
- If you take CYP450 substrate drugs, especially CYP1A2 or CYP2E1: Kava may increase both their effects and side effects.
- You take acetaminophen: Kava increased the liver toxicity caused by acetaminophen in laboratory studies.
Special Point:
- Although kava may provide short-term relief for anxiety, the risk of liver damage outweighs any benefits.