2.5/5
Weak
evidence
Focus / nootropic evidence brief
L-theanine
May support attention when paired with caffeine, but it is not a proven strength, endurance, or hypertrophy aid.
Headline Finding
Systematic review evidence is strongest for caffeine-plus-theanine attention, not standalone gym performance.
Dose Context
Often used alongside caffeine; the practical question is whether it improves focus without muting caffeine's useful arousal.
Important Caveat
Best understood as focus or stimulant-tolerability support, not a standalone gym-performance supplement.
Source Drawer
Linked Research
- Systematic review Caffeine/theanine cognition systematic review
- Meta-analysis Tea constituent meta-analysis
- Trial Athlete caffeine/theanine trial
- Trial Elite wrestler trial
- Position stand Caffeine performance position stand
How To Read This Rating
The score reflects evidence that the supplement does its stated job. Some jobs are direct, such as strength, endurance, or recovery; others are indirect, such as sleep, mood, appetite, or health support. A real effect can still receive a cautious practical rating when dose, safety, product quality, or audience fit remain uncertain.
Spot An Evidence Issue?
Send the disputed claim, source link, and why it changes the practical verdict. Corrections that materially affect the claim, dose, caveat, or rating are prioritized.
Report a source or rating issue