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 about cookies
Head-to-head evidence comparison — which supplement is right for you?
L-Theanine vs Tyrosine: L-Theanine has the stronger overall evidence (6 vs 6/10); they're alternatives for reduce anxiety & stress — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
L-Theanine wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Too few graded studies
1 of 1 studies with measurable effects showed benefit.
Top outcomes
Verdict
Too few graded studies
Top outcomes
Shared outcomes (2)
Outcomes where both L-Theanine and Tyrosine 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
500-2000mg (a typical label dose, not the dose used in the cited trials, which used 2 g five times a day for a week, or a single 100 mg per kg dose)
30-60 minutes before stressful activity, On empty stomach for best absorption
L-Tyrosine powder or capsules
30-60 minutes
30-60 minutes
30-60 minutes
Varies
30-60 minutes
30-60 minutes
30-60 minutes
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).
Tyrosine promotes cognitive flexibility: evidence from proactive vs. reactive control during task switching performance
Neuropsychologia (2015) · Rct · n=22
Tyrosine supplementation improved task switching performance under demanding conditions
Effect of tyrosine supplementation on clinical and healthy populations under stress or cognitive demands: A review
Journal of Psychiatric Research (2015) · Review
Converging evidence for cognitive enhancement under demanding conditions
The effect of tyrosine supplementation on whole-body endurance performance in physically active population: A systematic review and meta-analysis including GRADE qualification.
Journal of sports sciences (2023) · Meta analysis
No significant difference vs placebo for time to exhaustion (SMD = 0.02; p = 0.94)
Single-dose trials of L-theanine alone. In a crossover trial of 27 young adults given 100, 200 and 400 mg (PMID 32777998), only 400 mg shortened the P3b attention signal, and no dose changed reaction time. In a crossover trial of 20 healthy men, 200 mg improved recognition reaction time (PMID 26869148). In a crossover trial, 250 mg alone raised headache ratings and lowered correct serial subtractions, and the benefits came with caffeine (PMID 18006208). Most cognitive gains in this literature are for L-theanine combined with caffeine, which this curve does not show. The 400 mg ceiling rests on an 8-week trial of 80 schizophrenia inpatients, where side effects at 400 mg a day matched placebo (PMID 37697164). No trial found a best dose.
AI-estimated from published studies. Interpret as directional guidance.
L-Theanine has a higher evidence score (6/10 vs 6/10) and wins in 2 of 3 categories.
For reduce anxiety & stress, L-Theanine has a higher relevance score (85 vs 65).
No documented interaction was found in the data searched. This does not establish that this exact combination is safe.
The honest tier list — proven staples vs situational vs mostly marketing. The hub the other guides feed into.
Caffeine+L-theanine works; bacopa needs weeks; most "brain pills" are hype. The honest tier list.
Ashwagandha, L-theanine, magnesium, saffron — what actually helps stress, and the safety caveats.
Melatonin, magnesium, glycine, L-theanine — tiered by evidence, plus a wind-down timeline.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.