Kava carries a documented risk of serious liver injury, including cases that led to liver failure and transplant. That signal led several countries to ban or restrict kava products, and it is the reason this page opens with a warning rather than a description.
Kava is a plant preparation from the Pacific used for anxiety and sleep. It does have a sedative effect. The question is not whether it does anything, but whether the risk is one worth taking when other options exist.
Common side effects reported with this supplement or ingredient
- Drowsiness and sedation
- Impaired coordination and slowed reactions, which affects driving and operating machinery
- Headache and dizziness
- Stomach upset
- Numbness of the mouth after liquid preparations
- A dry, scaly skin rash with heavy sustained use
The serious effect is liver injury. It has occurred in people with no previous liver problem, has not been reliably predictable from the amount taken, and has sometimes appeared after only weeks of use.
Possible interactions with medicines, chronic conditions or pregnancy
- Alcohol. Combining them increases both sedation and the load on the liver. This is the combination to avoid most firmly.
- Sedatives and sleeping tablets, including benzodiazepines, and any medicine that causes drowsiness. See benzodiazepine side effects.
- Medicines that can affect the liver, which includes many ordinary ones. Paracetamol and kava together add avoidable risk.
- Anaesthesia. Tell the anaesthetist if you have been taking kava before any procedure.
- Antidepressants and other psychiatric medicines, where sedation compounds and the interaction picture is poorly mapped.
Who should speak to a healthcare professional before using it?
Anyone with any liver condition should not take kava. That includes hepatitis, fatty liver, and a history of alcohol-related liver problems.
It should also be avoided in pregnancy and breastfeeding, and by anyone who drinks regularly, takes several regular medicines, or is being treated for a mental health condition.
If you are reaching for kava because anxiety is affecting your sleep or daily life, that is worth treating properly. Anxiety has treatments with far better evidence and a far better safety record than this.
Dose, product-quality and stacking risks
Kava products vary in which part of the plant is used and how it is extracted, and both have been argued to affect risk. In practice you cannot verify either from the pack. Stacking kava with other calming or sleep supplements compounds the sedation without any of it being better studied. See herbal supplement side effects.
Supplements in South Africa are regulated as complementary medicines, and the checks applied are not the same as those for prescription medicines. See how supplements are regulated in South Africa.
When to stop and get medical advice
Stop immediately and get medical help the same day for any sign of liver injury: yellowing of the eyes or skin, dark urine, pale stools, pain under the right ribs, persistent nausea, unusual tiredness, or loss of appetite. Say that you have been taking kava, because it directs the tests that follow.
Also stop for heavy sedation, confusion, or a scaly rash. Report what happened, since these reports are how the picture on this product was built. See reporting a supplement side effect.
Related supplement safety guides
- Supplement side effects
- Supplement and medicine interactions
- Taking too many supplements
- When to see a doctor about a supplement
- Report a supplement side effect
See also supplements that affect the liver.
Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.