Kava is a plant in the pepper family native to the South Pacific, where kava drinks have been used for thousands of years. In the US it is sold as a dietary supplement and in kava bars, and it is promoted mainly for anxiety; it has been linked to rare but sometimes severe liver injury.
Also known as: kava kava, Piper methysticum, awa, kavalactones.
Kava has no intake value or upper limit, and NCCIH gives no standard amount. FDA's 2002 advisory says kava should be named in the Supplement Facts box, sometimes under other names such as awa, kawa, kava root or Piper methysticum.
It is sold in the US as a dietary supplement. Under the 1994 dietary supplement law (DSHEA), FDA does not approve dietary supplements before they are marketed, and the maker, not FDA, is responsible for safety and labeling. In 2002, FDA issued a consumer advisory that kava-containing supplements may be associated with severe liver injury. It cited more than 25 reports abroad of hepatitis, cirrhosis and liver failure, four of them needing liver transplants, and a previously healthy young woman in the US who needed a transplant. FDA advised people with liver disease or liver problems, or who take drugs that can affect the liver, to talk to a doctor before using kava, and noted that regulators in Germany, Switzerland, France, Canada and the UK had warned about or removed kava products.
What NCCIH says: kava supplements may help anxiety but may need several weeks to work, and kava does not appear to help generalized anxiety disorder. Kava products have been linked to rare liver injury, some serious or fatal, including with kava drinks made with water; suggested causes include the plant variety or part used, use with alcohol, contamination, genetics, and large or long-term use.
Kava can cause stomach upset, headache and dizziness, and long-term high use can cause kava dermopathy (dry, scaly skin, red eyes and yellowing of skin, hair and nails). Do not combine it with sedatives such as benzodiazepines or with alcohol. It may carry special risks in pregnancy and breastfeeding (NCCIH). FDA lists jaundice (yellow skin or eyes) and brown urine as signs of serious liver disease that need a doctor.
We could not find a single published half-life or time to peak for kava that applies to a supplement dose, so we do not list one. Herbal products are mixtures of many plant compounds, so no single figure would describe them.
How Dose Track handles peptides · Reconstitution calculator · Half-life calculator