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Sleep & stress

L-Theanine

Also known as: N-ethyl-L-glutamine · Theanine

An amino acid found in tea, commonly cited in the research literature for context around calm focus and stress.

L-Theanine at a glance

NameL-Theanine
Also known asN-ethyl-L-glutamine, Theanine
CategorySleep & stress
TypeAmino / injectable
SequenceNon-protein amino acid (N-ethyl-L-glutamine)
Typical dose~100-400 mg per day (commonly cited)
FrequencyOnce daily or as needed
RouteOral (supplement)
Half-lifeRelatively short, on the order of a few hours.

Overview

L-Theanine is a non-protein amino acid found naturally in tea leaves and some mushrooms. It is widely sold as a dietary supplement and has been studied for effects on relaxation, attention, and sleep quality, often in combination with caffeine. Presented for educational context only.

How it’s thought to work

  • Reported to increase alpha brain-wave activity associated with relaxed alertness.
  • Appears to modulate GABA, dopamine, and serotonin levels.
  • Studied for a dampening effect on the stimulant edge of caffeine.

Researched uses

  • Relaxation and stress reduction in human studies
  • Attention and reaction time when paired with caffeine
  • Sleep quality support in exploratory research

Commonly cited protocol

Typical dose~100-400 mg per day (commonly cited)
FrequencyOnce daily or as needed
RouteOral (supplement)
NotesTaken orally as capsules or powder; frequently combined with caffeine in research.

Reconstitution

Taken orally rather than injected, so insulin-syringe unit math does not apply.

Cautions

  • Sold as a dietary supplement; not an FDA-approved drug.
  • Generally well tolerated in studies, but individual responses vary.
  • May add to the effects of other calming agents.
  • Not intended to diagnose or treat any condition.

L-Theanine FAQ

What is L-Theanine?

An amino acid found in tea, commonly cited in the research literature for context around calm focus and stress.

How does L-Theanine work?

Reported to increase alpha brain-wave activity associated with relaxed alertness. Appears to modulate GABA, dopamine, and serotonin levels. Studied for a dampening effect on the stimulant edge of caffeine.

What is L-Theanine used for?

Relaxation and stress reduction in human studies; Attention and reaction time when paired with caffeine; Sleep quality support in exploratory research.

What is a typical L-Theanine dose?

~100-400 mg per day (commonly cited), Once daily or as needed, Oral (supplement). This is a commonly cited figure for context only, not medical advice.

How do you reconstitute L-Theanine?

Taken orally rather than injected, so insulin-syringe unit math does not apply.

What is the half-life of L-Theanine?

Relatively short, on the order of a few hours.

Related sleep & stress peptides

⚠️ Educational reference only — not medical advice. These compounds are largely research chemicals not approved for human use in most countries. Nothing here is a recommendation to obtain or administer any substance. Consult a qualified clinician.