Additive GABA modulation → excessive sedation
Additive CNS depression + additive hepatotoxicity
Additive liver stress
Kava has dopamine antagonist properties — may reduce levodopa effectiveness
Kava inhibits CYP2E1 (and other CYPs at high doses)
Additive CNS depression
Kava was banned in Germany, France, the UK, and other countries in 2002 after ~80 cases of hepatotoxicity, including some requiring liver transplant. Subsequent investigation found:
Our recommendation: Use only noble cultivar, root-only, water-extracted kava products from reputable manufacturers.
Not Prohibited
Pittler MH, Ernst E. Kava extract for treating anxiety. *Cochrane Database Syst Rev.* 2003.
(2003). PMID: 12535473
Sarris J et al. Kava for generalised anxiety disorder: a 16-week double-blind, randomised, placebo-controlled trial.
Teschke R, Schwarzenboeck A. Suspected hepatotoxicity by Cimicifugae racemosae rhizoma: the isopropanolic extract is not the cause.
Bian T et al. Kava as a clinical nutrient: promises and challenges.
Independently graded against 173,636 indexed supplements with 177 published clinical interactions, sourced from PubMed, FDA CAERS, openFDA, and NIH DSLD | Last updated: April 2026
Not medical advice. Based on published clinical research and systematic reviews.