Side Effects of Kava Kava

Reviewed by Terri Forehand RN
Kava bowl
Traditional Kava Bowl

Kava kava (Piper methysticum) has been used as a ceremonial drink by Pacific Islanders for hundreds of years. It also has been shown useful in the treatment of anxiety. However, kava kava can also have some serious side effects that you need to be aware of before you try it as an herbal remedy.

About Kava Kava

Kava kava is a shrub native to the Pacific Islands. The roots of the kava kava shrub are ground into a drink that is traditionally served at funerals and wedding as well as to important guests. It has a relaxing effect this is similar to alcohol, but without the hangover. The relaxing effect makes kava kava seem good for treating anxiety, insomnia and muscle tension.

The Side Effects of Kava Kava

While kava kava may sound like a good herb to use if you are dealing with anxiety, you should be sure you only use it under the close guidance of your health practitioner. Use of kava kava can cause some very serious health issues including the following side effects.

Liver Toxicity

There have been reports from the United States, Canada and Europe of liver toxicity which includes liver failure, cirrhosis, hepatitis and even death. It has been suggested that liver damage from kava is due to the inhibition of certain enzymes in the liver.

Some countries banned the use of kava kava because of this; however it appears that the use of kava kava is again legal in most countries though it is usually highly regulated. According to Herb Companion, most of the reported cases of liver damaged could be attributed to other causes such as the use of other liver damaging medications, using kava that has been adulterated with leaves and stems which contain liver damaging chemicals, kava extracts that are made with alcohol instead of water, and the simultaneous use of kava with drugs that affect the production of cytochrome P450 or in those with certain genetic deficiencies.

Signs to watch for include yellow skin, joint pain, fatigue, abdominal pain, loss of appetite, nausea and vomiting. Should you experience these symptoms, see your doctor immediately.


Dystonia, or involuntary muscle movements, can be caused by kava use. Those with Parkinson's disease should not take kava as medications used to treat Parkinson's may interact unfavorable with kava kava.

Skin Problems

High doses of kava kava may cause reactions such as scaly yellow skin, itching and even hair loss.

Other Potential Side Effects

There are more potential side effects of kava kava. An allergic reaction is always a possibility, as with anything. Kava should also be avoided if you are pregnant or breastfeeding and you should also not consume kava with alcohol.

If you will be having surgery, do not take kava. It's sedating affect can increase the effect of anesthesia. Be sure to let your doctor know if you have been taking kava before surgery.

High doses of kava kava can lead to vision problems. dizziness and poor balance. It can also have an effect similar to that of alcohol so do not take kava if you will be driving or operating machinery.


According to St. Luke's Hospital, kava kava should not be taken with the following medications:

  • Anticonvulsants: The effects may be increased with kava kava.
  • Anti-anxiety medications: Kava may increase the effect of benzodiazepines and barbiturates.
  • Diuretics: Kava may cause dehydration as it increases the effect of diuretics.
  • Phenothiazine medications: Side effects of these medications may increase if taken with kava kava.
  • Levodopa: The effect of this drug in treating Parkinson's may be reduced if taken with kava kava. Do not take kava if you have Parkinson's disease or if you take medications containing levodopa.

Be Safe

Kava kava can be a useful herb as long as it is used under the guidance of your healthcare provider. As always, be sure to tell your healthcare provider if you are taking any herbs and pay close attention to any adverse reactions. if you notice any unusual side effects, discontinue the use of kava and consult a professional for advice.

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Side Effects of Kava Kava