Kava

Piper methysticum · Kava Kava · Kavalactones

Snapshot

Indications	Contraindications
Anxiety relief^1–3 Generalized anxiety disorder^1–3 Nervous tension and restlessness⁴ Stress reduction⁵	Liver or kidney disease⁶ Sedative medication use⁶ Active alcohol use⁷ Pregnancy or breastfeeding⁷

Kava (Piper methysticum) is a Pacific Island root extract whose active compounds, the kavalactones, produce anxiolytic and sedative effects via gamma-aminobutyric acid (GABA) receptor potentiation and monoamine modulation⁷. It is taken primarily for anxiety relief and, secondarily, for stress and sleep, by patients seeking a non-pharmaceutical anxiolytic⁵. Practitioners considering it will encounter a safety profile dominated by rare but serious hepatotoxicity and a clinically meaningful dependence signal.

Randomized controlled trial (RCT) and meta-analysis evidence supports short-term anxiolytic activity against placebo^{8, 9}. A 16-week double-blind RCT in diagnosed generalized anxiety disorder (GAD) found no significant difference from placebo, and a global clinical guideline taskforce did not recommend kava for GAD^{1, 10}. In a 2025 systematic review examining kava consumption across social, economic, and health domains, the roles of kava in both liver toxicity and anxiety reduction were judged to remain unclear, underscoring the need for larger trials¹¹. Over 400 products listing kava are available in the United States as powders, capsules, and liquids; see Form comparison.

The most consequential contraindication is pre-existing liver disease: LiverTox rates kava a well-established cause of clinically apparent liver injury, with cases ranging from transient enzyme elevation to fulminant hepatic failure requiring transplantation¹². The National Center for Complementary and Integrative Health (NCCIH) notes that concurrent alcohol and sedative use compounds both hepatotoxic and sedation risk, requiring practitioner coordination rather than casual avoidance⁷.

Last updated October 7, 2026. Read how we make monographs.

In the full monograph

73 sources, 58 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources