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?
Vitamin B6 wins 1 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
Likely helps
9 of 11 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
25-100mg daily
Morning with food, Can take with other B vitamins
P-5-P (Pyridoxal-5-Phosphate)
30-60 minutes
30-60 minutes
30-60 minutes
Varies
2-4 weeks
1-2 cycles
Months of high doses
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).
Dosage exploration of combined B-vitamin supplementation in stroke prevention: a meta-analysis and systematic review
The American journal of clinical nutrition (2024) · Meta analysis · n=76664
In areas without and with partial folic acid fortification, combined B-vitamin supplementation significantly reduced the risk of stroke by 34% [RR: 0.66; 95% confidence interval (CI): 0.50, 0.86] and 11% (RR: 0.89; 95% CI: 0.79, 1.00), respectively.
Vitamin and mineral supplementation for maintaining cognitive function in cognitively healthy people in mid and late life
The Cochrane database of systematic reviews (2018) · Meta analysis · n=83000
We found that giving B vitamin supplements to cognitively healthy adults, mainly in their 60s and 70s, probably has little or no effect on global cognitive function at any time point up to 5 years (SMD values from -0.03 to 0.06) and may also have no effect at 5-10 years (SMD -0.01).
Drug Efficacy in the Treatment of Antipsychotic-Induced Akathisia: A Systematic Review and Network Meta-Analysis
JAMA network open (2024) · Meta analysis · n=492
No association between effect sizes and psychotic severity was found.
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 review of nutritional interventions for PMS psychological symptoms. Evidence quality limited by study heterogeneity and need for more consistent protocols.
AI-estimated from published studies. Interpret as directional guidance.
Vitamin B6 has a higher evidence score (9/10 vs 9/10) and wins in 1 of 3 categories.
For reduce anxiety & stress, L-Theanine has a higher relevance score (85 vs 55).
No known interactions between L-Theanine and Vitamin B6 have been documented in our database. However, always consult a healthcare provider before combining supplements.