Kava
Herbal products and dietary supplements
Herbal products and dietary supplementsPregnancy: avoid
Avoid in pregnancy. Its pyrone constituents may carry special risks in pregnancy and breastfeeding; use is discouraged.
A South Pacific pepper plant (Piper methysticum) used for anxiety. It is linked to rare, sometimes fatal, liver injury.
Also called: Piper methysticum, Kava kava
Quick facts
- Group
- Herbal products and dietary supplements
- Target
- Central nervous system (kavalactones; mechanism not established)
- Used for
- Promoted for anxiety
- Key effects
- Digestive upset · Headache and dizziness · Sedation
- Monitor
- Liver tests and symptoms of hepatitis · Sedation
No doses: the clinician sets them by the current guideline.
Mechanism of action
Kava root is made into drinks and extracts whose constituents (kavalactones and other pyrones) have calming effects. How they act in the brain is not well established. The liver injury has been linked to the plant variety and parts used, extraction method, adulteration, alcohol use, genetics and heavy or long use.
- Kavalactones are taken in drinks or extracts
- Calming effect on the brain (mechanism unclear)
- Rare liver injury, sometimes severe
Indications
- Promoted for anxiety: may help some anxiety symptoms but does not appear to help generalised anxiety disorder Generalized anxiety disorder →
Adverse effects
Common
- Digestive upset
- Headache and dizziness
- Sedation
Contraindications
- Liver disease
- Use with alcohol, benzodiazepines or other sedatives
Key interactions
- Alcohol
- More sedation and a suspected contribution to liver injury
- Benzodiazepines and other sedatives
- Additive sedation
- Other hepatotoxic drugs
- Added liver risk
What is monitored
- Liver tests and symptoms of hepatitis (jaundice, dark urine, fatigue)
- Sedation
Pregnancy and breastfeeding
Avoid in pregnancy. Its pyrone constituents may carry special risks in pregnancy and breastfeeding; use is discouraged.
Nursing care
- Ask every patient about herbal products and supplements and record them with the medicine list
- Teach the signs of liver injury and to stop kava and seek care if they appear
- Teach that «natural» does not mean safe and that supplements are not approved as medicines before sale
Pharmacokinetics
- Onset and duration
- Benefit for anxiety, if any, may take several weeks
Test yourself
Think of the answer, then tap the question to see it.
What is the main safety concern with kava?
Rare but sometimes fatal liver injury.
Which substances should not be combined with kava?
Alcohol, benzodiazepines and other sedatives.
What is kava dermopathy?
Dry, scaly skin with red eyes and yellowing of skin, hair and nails after heavy long-term use.
Connections
← Back to the class: Herbal products and dietary supplements
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: Kava: Usefulness and Safety (National Center for Complementary and Integrative Health (NCCIH), 2025).
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Representative model, for educational purposes only.