Search peptides — top sellers first
Search peptides — top sellers first
Search peptides — top sellers first
L-theanine for calm focus, everyday stress response, and settling before sleep.
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L-Theanine · mg
Frequently bought together
Researchers usually add these to complete the protocol.
Zinc Bisglycinate · mg
Popular · Foundation
Vitamin C · mg
Foundation
Vitamin D3 + K2 · mg
Foundation
Certificate of analysis
We don't publish a brand-wide spec sheet and call it a “COA.” The certificate you receive references the actual lot number stamped on your vial — with the raw chromatograms attached.
Vantage Analytical
Independent analytical lab
Certificate of Analysis
RESULT · PASS
Analytical results
HPLC Chromatogram
Purity
Know your compound
L-theanine is an amino acid found almost exclusively in tea leaves. It crosses the blood-brain barrier and is associated with increased alpha-wave activity — the EEG pattern the brain shows during relaxed alertness, not drowsiness. In studies it also appears to influence GABA, dopamine, and serotonin signaling. Dietary intake from tea is small, which is why isolated supplementation is studied at all.
In one randomized trial, 200 mg cut EEG stress markers and slowed heart rate during a stressful task. Most of the literature looks at single acute doses rather than weeks of daily use, and the subjective calm and attention effects, while consistent, are modest. Researchers keep returning to L-theanine for one reason: the alpha-wave finding is well replicated.
For research use only — not for human or veterinary use.
The research
The published findings behind this compound — the headline numbers, in plain terms, each cited to source. Preclinical results are directional (animal / in-vitro) and shown for context, not as therapeutic claims.
Published research on the reference compound class. Provided for scientific context only — not a claim about the product supplied.
In healthy adults given a single 200 mg dose, L-theanine was associated with a slower heart rate and lower salivary stress markers during a demanding task versus placebo.
Directional: heart rate & salivary stress markers during a stress task; study did not report a single effect size.
In healthy adults, pairing L-theanine with caffeine shifted attention-switching accuracy and subjective alertness more than either compound taken alone in acute testing.
Directional: acute attention and alertness measures; no single quantified effect reported.
In healthy adults, four weeks of daily L-theanine was associated with changes in stress-related symptom scores and select cognitive measures compared with placebo.
Relative direction of stress-symptom scores (lower = fewer symptoms); illustrative of reported trend, not exact values.
Mechanism
L-theanine is studied to act through three distinct routes in the brain.
L-theanine is associated with increased alpha-wave EEG activity, the pattern linked to a calm, alert state rather than sedation.
It is studied for its influence on GABA, dopamine, and serotonin signaling, systems involved in mood and arousal.
When taken with caffeine, it is studied for how it modulates the subjective and attentional effects of the stimulant.
For research use only. Mechanisms described reflect published preclinical and clinical literature.
The process
Synthesized
Produced under controlled manufacturing with documented, repeatable processes.
HPLC purity
An independent lab reports the exact purity of every lot — a number, never a 'passes'.
Mass-spec identity
Molecular weight confirms the exact sequence is what the label says.
COA published
The certificate is posted to the open library, by lot, before the vial ships.
Best sellers
FAQ
Common questions about L-Theanine
The COA guarantee
Have any lot independently re-tested. If the results don't match the published certificate, we refund the order in full — no returns, no questions.
Order with coverThird-party tested
An independent, accredited lab — no commercial interest in the result.
A COA on every lot
A lot-specific certificate ships with each vial, archived by batch.
Test it yourself → refund
Re-test any batch at any lab. A mismatch is a full refund.
