Amino Acid
L-Theanine
An amino acid known for promoting calm focus and reducing stress without sedation.
KÖGN Health grades L-Theanine as A+ (Strong evidence) and rates it 4.6 out of 5.
Last reviewed · June 2026
Primary effects
- Improved focus
- Reduced anxiety
- Enhanced relaxation
How it works
Enhances alpha brain wave activity and modulates neurotransmitters for calm, focused attention.
Overview
L-Theanine is one of the most well-studied nootropics for promoting relaxed alertness. It is particularly effective when combined with caffeine, as it reduces jitteriness while preserving cognitive stimulation. Its effects are noticeable within a short period and are consistent across users, making it a foundational compound for both productivity and stress management.
The evidence
Well supported, especially in combination with caffeine: the pairing improves attention and task accuracy while reducing the jittery side of caffeine. On its own, evidence points to reduced stress reactivity.
Dose
100–200 mg per serving. Commonly paired with caffeine at roughly a 2:1 ratio (e.g. 200 mg with 100 mg caffeine).
Timing
Acute — effects within 30–60 minutes. No tolerance build-up.
Safety
Very well tolerated with no notable interactions at typical doses. Non-stimulating and non-habit-forming.
Works well with
Related ingredients
Graded entries that target the same cognitive goals.
Categories
Educational information, not medical advice. The evidence grade is KÖGN’s editorial assessment of published research, not a health claim. Speak to a qualified clinician before changing what you take.