StackTerminal.Health

L-Theanine

Often paired with caffeine for 'calm focus'; evidence suggests reduced jitteriness and improved attention in some contexts.

focusstresscaffeine
Dosing model
FLATFixed dose (no body-weight scaling).
Min dose
100 mg
Max dose
200 mg
Rounding
25 mg

Stacks containing L-Theanine

Public community stacks that include this ingredient.

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sleepwomens-health

Cycle-phase support focused on calm and sleep quality without stimulants.

Vitex agnus-castus
20mg
Glycine
3000mg
L-Theanine
200mg
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focus

Supports focus and mental clarity without stimulants.

L-Theanine
200mg
L-Tyrosine
1000mg
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recoverysleep

Designed to support sleep quality, parasympathetic activation, and overnight recovery without heavy sedation.

Magnesium Glycinate
400mg
Glycine
3000mg
L-Theanine
200mg
+ 1 more supplements
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focus

Supports alertness with lower jitter risk than caffeine.

Theacrine
100mg
L-Theanine
200mg
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sleepfocus

Supports attention and cognitive resilience without stimulants.

L-Theanine
200mg
L-Tyrosine
1000mg
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Evidence
2 records
Attention and cognitive performance (combined with caffeine)
Healthy adultsRCT (double-blind, crossover)
Moderate

L-theanine (100 mg) + caffeine (50 mg) improved attention-switching speed and accuracy vs. placebo at 60 min; L-theanine alone showed no significant cognitive effects.

Dose: 200 mg Duration: Acute
Most consistent evidence is for the caffeine + theanine combination, not theanine alone.
Cognitive function (standalone L-theanine)
Healthy adults (5 RCTs, n=148)Systematic review & meta-analysis of RCTs
Low

L-theanine showed dose-dependent effects on rapid visual information processing and recognition reaction time; non-significant for simple reaction time and Stroop. Overall evidence promising but not conclusive.

Dose: 200 mg Duration: Acute to 4 weeks
Standalone effects are less consistent than combination with caffeine.
Forms
L-Theanine
Commonly 100–200 mg with caffeine.