Reviewed by the Scan Dose Research Team and Clinical Advisory Board
Kava
MODERATE EVIDENCESupplementLast updated April 2026
SCAN DOSE SUMMARY
Kava is a Pacific Island ceremonial plant with strong evidence for anxiety reduction — head-to-head comparable to benzodiazepines in some trials. Our research confirms it works through GABA modulation, not serotonergic pathways, making it one of the few natural anxiolytics that doesn't interact with SSRIs through serotonin. However, the hepatotoxicity signal — while likely related to poor-quality extracts and stem/leaf contamination — caused bans in several countries and remains the primary safety concern.
Kava has dopamine antagonist properties — may reduce levodopa effectiveness
CYP2E1 substratesModerate
Kava inhibits CYP2E1 (and other CYPs at high doses)
Sedatives / barbituratesSevere
Additive CNS depression
SAFETY PROFILE
Drug Interactions
⚠️ Hepatotoxicity Concern
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:
Most cases involved acetone or ethanol extracts (not traditional water extracts)
Stem peelings and leaves (which contain pipermethystine, a hepatotoxin) were often included
Noble root cultivars prepared as water extract have been used safely for 3,000+ years in Pacific cultures
Germany lifted its ban in 2015 after review
Risk is real but largely attributable to poor manufacturing, not kava itself
Our recommendation: Use only noble cultivar, root-only, water-extracted kava products from reputable manufacturers.