Kava Side Effects

The herb kava, or Piper methysticum, comes from the South Pacific islands, where inhabitants have used the dried root of the plant for hundreds of years as a ceremonial, medicinal and social beverage. Modern-day Westerners primarily use kava supplements to treat anxiety and insomnia. While evidence supports kava's efficacy in treating anxiety, there is a growing body of evidence that kava also causes severe side effects. Before using kava, consult a health care practitioner for advice.

Liver Toxicity

Liver toxicity is one of kava's most serious side effects. The Food and Drug Administration issued an advisory in 2002 warning consumers about kava's potentially deadly effects on the liver. In addition to hepatitis and cirrhosis, kava has been linked to liver failure and the need for liver transplants. The exact reason for kava's effect on the liver isn't yet understood, according to the University of Maryland Medical Center. A 2004 study published in "Planta Medica" suggested that many of the reported cases of liver failure may not be connected with kava use at all; however, the study also warned that liver toxicity cannot be ruled out as one of kava's side effects.
If you are taking kava and experience fatigue, nausea, joint pain, vomiting, loss of appetite or abdominal pain, consult a doctor as soon as possible; these are signs of liver damage. (See References 3.)

Kava Dermopathy

Chronic, heavy use of kava causes a skin condition called kava dermopathy. People with this type of dermopathy develop skin eruptions resembling scales, and their skin, fingernails and toenails turn yellow. The Tang Center for Herbal Medicine Research says that kava dermopathy is reversible when kava used is stopped.

Abnormal Muscle Movement

The National Library of Medicine and the National Institutes of Health warn that kava may cause abnormal muscle movement after using it for as little as one to four days. In these cases, kava makes the muscles of the neck, eyes and mouth lock, twist or tighten. Tremors and coordination problems may also occur.