SeriousCaution
Melatonin
Both can impair alertness; kava also carries liver safety concerns.
Recommendation: Avoid routine stacking and do not combine before driving, alcohol use, or sedative medication use.
Kava
Herb ·Moderate evidence ·Reviewed May 2026
Kava root preparations have randomized-trial and systematic-review evidence for anxiety symptom reduction, but safety concerns include rare severe liver injury and additive sedation. Risk appears influenced by dose, duration, plant part, cultivar, extraction method, product quality, alcohol, and comedications. Kava should be avoided in liver disease, pregnancy, heavy alcohol use, and with sedatives unless clinician-supervised.
The bottom line
Evidence rating moderate. Most-documented uses: may reduce anxiety symptom scores, may promote relaxation, may reduce muscle tension. 3 sources indexed (2003–2013), with 3 interaction records on file.
The science
How it works, mechanistically.
Core mechanism
Kavalactones such as kavain, dihydrokavain, methysticin, and yangonin modulate neuronal excitability through sodium and calcium channels, GABAergic tone, monoamine signaling, and limbic arousal pathways. These mechanisms can produce anxiolysis and muscle relaxation but also sedation and psychomotor impairment. Hepatotoxicity appears idiosyncratic or product-quality related in some cases, so conservative use and quality sourcing are essential.
Class
Kavalactone anxiolytic with hepatic safety concerns
Found in food
Traditional kava beverage prepared from root and rhizome
Low-status signs
None - kava is not an essential nutrient and has no deficiency state
Absorption
Fat-soluble; take with food
Dosing
Dosing & protocol.
Common range
60-250 mg/day total kavalactones for short-term use in clinical anxiety studies; avoid prolonged or high-dose use
Recommended form
Noble kava root-only aqueous or well-characterized extract with disclosed kavalactone dose
Taking with food may reduce GI upset. Avoid alcohol and avoid products made from aerial parts or unclear extracts.
Forms
Forms & what to buy.
Ranked by evidence and value.
Standardized Kavalactone Extract Recommended
Clinically interpretable when total kavalactones and plant part are disclosed. Take with food and no alcohol.
Traditional Noble Kava Beverage
Preparation varies but root-only noble kava is preferred over unclear extracts. Avoid alcohol and sedatives.
High-Potency Kava Capsule
Higher kavalactone exposure may increase adverse effect risk. Use only short term if at all.
Cost
What it actually costs.
Real-world pricing across three quality tiers. Assumes Standardized kava root extract.
BudgetBest value
$6 /mo
$0.20 per dose
Mid
$17 /mo
$0.55 per dose
Premium
$45 /mo
$1.50 per dose
Quality-tested root-only products are preferred even if they cost more. Updated 2026-06-04.
Goals
Goal-based dosing.
Lab work
Markers to track.
What to test, the optimal window inside the conventional range, and how long a response takes.
Alanine Aminotransferase ALT
Should remain stable; elevations may indicate liver stress or unrelated liver disease.
Optimal
7–35 U/L
Conventional
7–55 U/L
Responds in
Baseline and within 2-6 weeks if using longer than occasional short-term use
7optimal55
Stop kava and seek medical care for jaundice, dark urine, severe fatigue, right upper quadrant pain, or unexplained nausea.
ASTAlkaline phosphataseBilirubinGGT
Why people use it
Symptoms it's matched to.
Where this appears in the symptom-to-supplement map, ranked by relevance.
Anxiety
68% relevance
Kavalactones reduce neuronal excitability and may support GABAergic calming.1,2
MoodModerate evidenceRoot-only standardized extract
Avoid in liver disease, alcohol use, and sedative medication use.
Muscle tension from stress
42% relevance
Kavalactones may produce muscle relaxation and anxiolysis.
MusculoskeletalEmerging evidenceLow-dose root extract
Do not drive after sedating doses.
Difficulty falling asleep
38% relevance
May help when sleep difficulty is anxiety-driven.1,2
SleepEmerging evidenceEvening low-dose kava
Not preferred for chronic nightly use because of liver and sedation concerns.
Safety
Full safety detail.
Side effects
- Drowsiness
- Dizziness
- GI upset
- Headache
- Mouth numbness
- Dry scaly skin with heavy use
- Liver enzyme elevation or rare severe liver injury
Interactions
Interaction records.
SeriousCaution
Ashwagandha
Both can cause sedation, and both have rare liver-injury concerns in case reports.
Recommendation: Avoid high-dose or long-duration combination; stop for liver symptoms or unusual fatigue.
ModerateCaution
5-HTP
Both may affect CNS state and sleepiness; 5-HTP adds serotonergic considerations.
Recommendation: Avoid combining with antidepressants or sedatives unless clinician-reviewed.
Sources
Sources, by evidence tier.
Numbered references. Citations throughout the page link here.
Meta-analyses & systematic reviews
1- 1Kava extract for treating anxietyNeeds sourceNo linkPittler MH et al. · Cochrane Database of Systematic Reviews · 2003
Meta-analysis of controlled trials suggested anxiolytic benefit, with safety caveats.
Randomized controlled trials
1- 2Kava in the Treatment of Generalized Anxiety Disorder: A Double-Blind, Randomized, Placebo-Controlled StudyNeeds sourceNo linkSarris J et al. · Journal of Clinical Psychopharmacology · 2013
Kava was evaluated for GAD symptoms with liver function monitoring.
Reviews & position papers
1- 3Kava hepatotoxicity--a clinical reviewNeeds sourceNo linkTeschke R et al. · Annals of Hepatology · 2010
Structured causality assessments identified probable and possible cases of kava-associated liver injury.
Keep exploring
Deep dives & adjacent profiles.
This page is educational. Do not start, stop, or change a supplement or medication based on it without checking with a qualified healthcare professional.
Use this with your stack
Kava in NutriStack.
Add it to your stack, see how it interacts with everything else you take, and get a Stack Score that updates the moment it does.