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Head-to-head evidence comparison — which supplement is right for you?
L-Theanine wins 1 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
4 of 5 studies with measurable effects showed benefit.
Top outcomes
Verdict
Mostly mechanism / observational
1 of 1 studies with measurable effects showed benefit.
Top outcomes
Shared outcomes (1)
Outcomes where both L-Theanine and Phosphatidylserine have evidence — compare verdict strength side-by-side.
100-200mg
Morning with coffee for focus, Evening for relaxation, As needed for stress
Suntheanine® capsules or powder
100-300mg daily
With meals, Evening or post-workout for cortisol
Soy or sunflower-derived phosphatidylserine
30-60 minutes
30-60 minutes
30-60 minutes
Varies
4-12 weeks
2 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).
Effects of a food supplement containing phosphatidylserine on cognitive function in Chinese older adults with mild cognitive impairment: A randomized double-blind, placebo-controlled trial
Journal of affective disorders (2025) · Rct · n=190
A total of 190 participants (mean [SD] age, 67.95 [5.62] years; 70 (36.8 %) male and 120 (63.2 %) female) were randomized to the placebo group (n = 95) and intervention group (n = 95).
Phosphatidylserine containing omega-3 fatty acids may improve memory abilities in non-demented elderly with memory complaints: a double-blind placebo-controlled trial
Dementia and geriatric cognitive disorders (2010) · Rct · n=157
157 participants were randomized to receive either PS-DHA or placebo for 15 weeks.
Phosphatidylserine for the Treatment of Pediatric Attention-Deficit/Hyperactivity Disorder: A Systematic Review and Meta-Analysis
Journal of alternative and complementary medicine (2021) · Meta analysis · n=216
Four studies met the inclusion criteria for the narrative review (n = 344) and three for the meta-analysis (n = 216).
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 RCT in 190 Chinese older adults with mild cognitive impairment and systematic review of neuronutrients. Limited by small number of direct studies and population-specific findings.
AI-estimated from published studies. Interpret as directional guidance.
L-Theanine has a higher evidence score (6/10 vs 6/10) and wins in 1 of 3 categories.
For reduce anxiety & stress, L-Theanine has a higher relevance score (85 vs 65).
No known interactions between L-Theanine and Phosphatidylserine have been documented in our database. However, always consult a healthcare provider before combining supplements.