Kava (Piper methysticum) is a plant of the pepper family native to the South Pacific. Pacific Islanders have used kava beverages for thousands of years for ceremonial and medicinal purposes. According to the US NCCIH, the drink has spread to other parts of the world and kava drinks are now sold at kava bars at many locations in the United States; kava products are promoted for anxiety and other health conditions. (NCCIH — Kava) A 2020 FDA scientific memorandum notes that kava is sold in the US as a dietary supplement promoted for relaxation, stress and anxiety — and also for sleeplessness. (FDA — Scientific Memorandum: Kava, 2020)
This article summarises the evidence; it is not a diagnosis or a treatment.
Does kava help you sleep?
On its sleep page, NCCIH writes that although kava is said to have sedative properties, very little research has been conducted on whether it helps insomnia. (NCCIH — Sleep Disorders and Complementary Health Approaches) Most research is on anxiety: according to NCCIH, kava supplements may help, but may need to be taken for several weeks; kava does not appear to help symptoms of generalised anxiety disorder. For other conditions there isn't enough evidence. (NCCIH — Kava)
Read soberly: evidence that kava improves sleep is missing.
Why safety is the main question
- According to NCCIH, kava products have been linked to rare cases of liver injury, some of them serious or even fatal. The first reported cases involved extracts made with alcohol or acetone, but other cases involved beverages prepared with water. (NCCIH — Kava) The exact cause and frequency of the liver damage are unclear. (NCCIH — Sleep Disorders and Complementary Health Approaches)
- Suggested possible reasons include unsuitable varieties or parts of the plant, use together with alcohol, adulteration or contamination of products, genetic differences between people, and use in large amounts or for long periods. (NCCIH — Kava)
- Kava can also cause digestive upset, headache and dizziness. Long-term use of high doses may cause kava dermopathy — dry, scaly skin, reddened eyes and temporary yellow discolouration of the skin, hair and nails. (NCCIH — Kava)
- The 2020 FDA memorandum states that liver safety concerns have led, since 2002, to withdrawal or bans of kava in several European markets (the memo lists, among others, the Czech Republic; in Germany a ban applied until 2015) and in Canada, and that the FDA issued a consumer advisory in 2002. In the memo, which assesses kava as an ingredient in conventional foods, FDA toxicologists concluded that indiscriminate use of kava as a “recreational” or “relaxation” beverage is not safe. Rules can differ between countries and change. (FDA — Scientific Memorandum: Kava, 2020)
Kava, alcohol and medicines
- According to NCCIH, kava should not be combined with other sedative substances such as benzodiazepines or alcohol. If you take any medicine, talk to your doctor before using kava. Kava may carry special risks during pregnancy and breastfeeding. (NCCIH — Kava)
- The NHS says not to take herbal medicines if you are pregnant or breastfeeding, have kidney or liver problems or take certain medicines; they are not recommended for children. Don't buy unlicensed herbal medicines online. (NHS — Herbal medicines and complementary therapies)
When to see a doctor
- Yellowing of the skin or the whites of the eyes can, according to the NHS, be a sign of something serious such as liver disease — get urgent medical help. You may also have itchy skin, darker pee and paler poo. (NHS — Jaundice) If you have used kava, say so.
- The NHS advises seeing a GP if changing your sleeping habits has not helped, you've had trouble sleeping for months, or insomnia is affecting your daily life. (NHS — Insomnia) According to NCCIH, the most strongly recommended treatment for insomnia is cognitive behavioural therapy for insomnia (CBT-I). (NCCIH — Sleep Disorders and Complementary Health Approaches)
- Always tell your doctor about herbal products you use, and don't stop prescribed medicines without talking to them first. (NHS — Herbal medicines and complementary therapies)
- An AI health check is not a medical review. This article is not medical advice.
Takeaways
- Kava is a Pacific plant whose drinks are spreading beyond the Pacific; in the US it is also sold in kava bars.
- Very little research has looked at kava for insomnia — evidence that it helps sleep is missing.
- Kava has been linked to rare but sometimes serious or fatal liver injury.
- Don't combine it with alcohol or sedative medicines; avoid it in pregnancy, breastfeeding and with liver disease.
- Yellow skin or eyes → urgent medical help; long-term insomnia → see a doctor, CBT-I.
If you are considering kava, talk to a doctor or pharmacist first — there are better-tested routes to sleep.
Our sources
Research and further reading. Practical suggestions are editorial ideas, not a personalised treatment plan.
