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L-Theanine

Amino Acids

Also known as: Theanine, γ-glutamylethylamide

L-Theanine is an amino acid found primarily in green tea. It promotes relaxation without drowsiness, enhances focus, and is one of the best-studied compounds for reducing anxiety while maintaining cognitive clarity.

Best Timing

For focus: take in the morning with caffeine. For sleep: take 30–60 minutes before bed. Fast-acting (effects in 30–60 min).

Absorption

Rapidly absorbed, crosses the blood-brain barrier within 30 minutes. Can be taken on an empty stomach.

Health Goals
🧠Focus🌙Sleep😊Mood
Who Should Take This
StudentsHigh-Stress IndividualsAthletes
  • Promotes calm focus without drowsiness
  • Reduces anxiety and stress
  • Enhances alpha brain waves (associated with creativity and relaxation)
  • Improves sleep quality when taken at night
  • Synergizes with caffeine for jitter-free focus
  • May support immune function
Calm focus100–200 mg

As needed

Often paired with caffeine

Anxiety reduction200–400 mg

Daily or as needed

Sleep support200–400 mg

30–60 min before bed

With caffeine100–200 mg L-theanine + 50–100 mg caffeine

As needed

2:1 ratio of theanine to caffeine

  • -L-Theanine (free form) – standard supplement form
  • -Suntheanine – patented, pure L-isomer form
Green tea (primary natural source)Black teaWhite teaSome mushrooms (Boletus badius)
MagnesiumSynergy

Both promote relaxation and improve sleep quality. Great evening stack.

AshwagandhaSynergy

Complementary anxiety-reducing mechanisms. Effective anxiolytic stack.

Omega-3Synergy

Both support cognitive function and mood through different pathways.

L-theanine, a natural constituent in tea, and its effect on mental state

Nobre AC, Rao A, Owen GN. - Asia Pacific Journal of Clinical Nutrition (2008)

L-theanine significantly increased alpha brain wave activity, indicating relaxation without sedation.

The combined effects of L-theanine and caffeine on cognitive performance and mood

Owen GN, Parnell H, et al. - Nutritional Neuroscience (2008)

The combination improved speed and accuracy on attention tasks and reduced susceptibility to distracting information.