Since a number of problems have been linked to the use of kava, safety warnings and precautions for the supplement should be thoroughly reviewed before starting it. Kava may not be safe for anyone, and you may be at an even higher risk for problems if you have Parkinson's disease, liver disease, or depression. Kava could worsen Parkinson's symptoms, cause serious liver damage, and worsen depression.
Kava (Piper methysticum) is an herbal supplement often used to treat anxiety, although it is sometimes used for other purposes. Kava may not be safe for anyone; you may be at an especially high risk for problems if you:
- Have liver disease, such as liver failure, cirrhosis, or hepatitis
- Have Parkinson's disease
- Have depression
- Have any allergies, including allergies to food, dyes, or preservatives
- Are pregnant or thinking of becoming pregnant
- Are breastfeeding.
You should also be sure to tell your healthcare provider about all other medicines you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.
Warnings and precautions to be aware of concerning the safety of kava include the following:
- There have been several reports of serious liver injury due to kava. Some of these cases were serious enough to require liver transplants. As a result, kava has been banned in several countries. In the United States, kava is still available, although the FDA has issued a warning about the possibility of liver damage. If you already have liver problems, you should not take kava.
- Kava can worsen Parkinson's disease symptoms. If you have Parkinson's disease, you should not take kava.
- Kava can cause unusual, uncontrollable body movements (such as tremors). If you develop such movements, stop taking kava and check with your healthcare provider right away.
- There is some concern that kava could make depression worse. If you have a history of depression, you should probably avoid kava.
- Kava supplements can interact with many medications (see Kava Drug Interactions for more information).
- It is not known whether kava is safe for pregnant or breastfeeding women (see Kava and Pregnancy and Kava and Breastfeeding).
- If you decide to use supplements, what you see on the label may not reflect what is in the bottle. For example, some herbal supplements have been found to be contaminated with heavy metals or prescription drugs, and some have been found to have much more or much less of the featured ingredient than their label states. Therefore, make sure the manufacturer of your kava product is a trusted and reputable manufacturer. It is a good sign if a manufacturer abides by the rules of Good Manufacturing Practices (GMP). It is also a good sign if a product has the United States Pharmacopoeia (USP) seal, which means that it has been independently tested and shown to contain the correct ingredients in the amounts listed on the label. Your pharmacist is a good resource for information about which manufacturers are most reputable.