L-theanine
Cognitive · Amino acid (tea-derived)
Tier B+
Bottom line
Read Off Label grades L-theanine as B+ (7.1/10) based on moderate evidence, med benefit magnitude, and a low-risk safety profile.
Combination with caffeine is the most evidence-backed nootropic stack — Camfield 2014 meta-analysis showed moderate improvements in attention switching/accuracy in first 2 hours post-dose.
Typical use: 100-400 mg/day; commonly 100-200 mg paired with caffeine — OTC.
What this is
Combination with caffeine is the most evidence-backed nootropic stack — Camfield 2014 meta-analysis showed moderate improvements in attention switching/accuracy in first 2 hours post-dose. Ratio typically 2:1 theanine:caffeine.
Mechanism
Non-proteinogenic amino acid from tea; crosses BBB; increases alpha brain waves; mild GABA agonism; glutamate receptor modulation; calming without sedation
Dose & route
100-400 mg/day; commonly 100-200 mg paired with caffeine
Citations
- https://pubmed.ncbi.nlm.nih.gov/24946991/
- https://pubmed.ncbi.nlm.nih.gov/40314930/
- https://www.mdpi.com/2077-0383/14/21/7710
Links go to the source. If a link is dead or you want something re-checked, let me know.
Common questions
- Does L-theanine work?
- Read Off Label rates the evidence for L-theanine as Moderate and the benefit magnitude as med, producing an overall grade of B+ (7.1/10). Combination with caffeine is the most evidence-backed nootropic stack — Camfield 2014 meta-analysis showed moderate improvements in attention switching/accuracy in first 2 hours post-dose.
- Is L-theanine safe?
- L-theanine has a low risk profile in published human data. Legal status: OTC. This is not medical advice — see the disclaimer.
- What is the typical dose for L-theanine?
- 100-400 mg/day; commonly 100-200 mg paired with caffeine
- How does L-theanine work?
- Non-proteinogenic amino acid from tea; crosses BBB; increases alpha brain waves; mild GABA agonism; glutamate receptor modulation; calming without sedation
This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.