Loading…
We use essential cookies (authentication, your saved goals/stack) by default. With your permission we'll also enable privacy-respecting analytics (Vercel Web Analytics, anonymous load-time metrics) and error-replay diagnostics (Sentry — DOM snapshots only when an error fires) so we can fix bugs faster. Learn more
Head-to-head evidence comparison — which supplement is right for you?
L-Theanine wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Probably helps
4 of 7 studies with measurable effects showed benefit.
Top outcomes
Verdict
Likely helps
3 of 4 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (3)
Outcomes where both Kava and L-Theanine have evidence — compare verdict strength side-by-side.
150-300mg kavalactones daily
Evening for relaxation, 30-60 minutes before stressful events, Before bed for sleep
Water-extracted root powder or capsules
100-200mg
Morning with coffee for focus, Evening for relaxation, As needed for stress
Suntheanine® capsules or powder
30-60 minutes
30-60 minutes
30-60 minutes
1-2 hours
30-60 minutes
30-60 minutes
30-60 minutes
Varies
Herbal medicines in the treatment of psychiatric disorders: 10-year updated review
Phytotherapy research : PTR (2018) · Systematic review
Other encouraging herbal medicines with preliminary evidence include Curcuma longa (turmeric) in depression, Withania somnifera (ashwagandha) in affective disorders, and Ginkgo biloba (ginkgo) as an adjunctive treatment in Schizophrenia.
GABA-modulating phytomedicines for anxiety: A systematic review of preclinical and clinical evidence
Phytotherapy research : PTR (2018) · Systematic review
An open-ended search to 5 July 2017 was conducted using MEDLINE (PubMed), Scopus, and Cochrane library online databases and performed in a stepped format from preclinical to clinical investigations.
Herbal medicine for insomnia: A systematic review and meta-analysis
Sleep medicine reviews (2015) · Meta analysis · n=1602
There was no statistically significant difference between any herbal medicine and placebo, or any herbal medicine and active control, for any of the thirteen measures of clinical efficacy.
The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis
Sleep medicine reviews (2025) · Meta analysis · n=897
The findings indicate the potential use of L-theanine in the management of sleep disturbances; however, the lack of studies on "pure" L-theanine warrants further investigation.
Efficiency of Different Supplements in Alleviating Symptoms of ADHD with or Without the Use of Stimulants: A Systematic Review
Nutrients (2025) · Systematic review
The evidence revealed the potential use of supplements as complementary ADHD treatments under clinical guidance.
Analysis of the Effects of Known Sleep-Support Supplements in Relation to Life Habits, Sleep Conditions, and Sleep Problems
Nutrients (2023) · Rct · n=160
All the tested supplements were found to ameliorate sleep problems significantly (Analysis 1).
Based on multiple meta-analyses showing efficacy vs placebo with effect size comparable to benzodiazepines for mild-moderate anxiety. WS1490 extract showed OR=3.3 vs placebo. Effectiveness limited to 60% due to mixed results in some GAD populations and study quality limitations.
Meta-analysis (n=897) and multiple RCTs support sleep benefits. Studies often used L-theanine in combination with other compounds, limiting pure L-theanine effect attribution. Effects include reduced sleep onset latency and improved subjective sleep quality.
AI-estimated from published studies. Interpret as directional guidance.
L-Theanine has a higher evidence score (9/10 vs 9/10) and wins in 2 of 3 categories.
For reduce anxiety & stress, Kava has a higher relevance score (90 vs 85).
No known interactions between Kava and L-Theanine have been documented in our database. However, always consult a healthcare provider before combining supplements.