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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
Likely helps
3 of 4 studies with measurable effects showed benefit.
Top outcomes
Verdict
Mixed evidence
2 of 6 studies with measurable effects showed benefit.
Top outcomes
100-200mg
Morning with coffee for focus, Evening for relaxation, As needed for stress
Suntheanine® capsules or powder
1-3g dried mushroom or 500-1500mg extract
Evening (for sleep), With or without food
Dual-extract (water + alcohol) capsules or powder
30-60 minutes
30-60 minutes
30-60 minutes
Varies
4-8 weeks
2-4 weeks
4-8 weeks
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).
Identifying immunostimulatory herbal supplements that may flare autoimmune skin diseases: a systematic scoping review
Lupus science & medicine (2025) · Systematic review · n=469
We identified 227 herbal supplements with immunostimulatory properties, of which 15 were most strongly supported by the evidence.
Ganoderma lucidum (Reishi) an edible mushroom; a comprehensive and critical review of its nutritional, cosmeceutical, mycochemical, pharmacological, clinical, and toxicological properties
Phytotherapy research : PTR (2021) · Systematic review
In particular, quality clinical data are intensely needed to support pharmacological activities for human use.
Use of Ganoderma lucidum (Ganodermataceae, Basidiomycota) as Radioprotector
Nutrients (2020) · Meta analysis
From a total number of 1109 records identified, 15 full text articles were eligible, none of them were clinical trials.
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.
Based on systematic reviews identifying immunostimulatory properties. Meta-analysis for cancer adjuvant therapy showed positive immune response (RR 1.50). Quality clinical data still needed. Effect varies significantly by extract type and standardization.
AI-estimated from published studies. Interpret as directional guidance.
L-Theanine has a higher evidence score (9/10 vs 7/10) and wins in 2 of 3 categories.
For reduce anxiety & stress, L-Theanine has a higher relevance score (85 vs 60).
No known interactions between L-Theanine and Reishi have been documented in our database. However, always consult a healthcare provider before combining supplements.