Botanical Library
L-Theanine
Nutrition tradition
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At a glance
Where it's from
Occurs naturally in green and black tea (Camellia sinensis) and some mushrooms.
Look & taste
A white crystalline amino acid found naturally in tea leaves. Slightly savoury (umami)
Signature compounds
L-theanine itself - an amino acid.
Traditionally used for
Not a traditional-medicine herb - the calming amino acid naturally found in tea.
In Canada, we can say...
Helps to temporarily promote relaxation.
Did you know?
It is thought to be why a cup of green tea feels calmer than the same caffeine from coffee.
History & natural history
Identified in green tea in 1949; credited with tea's calm-yet-alert feeling.
What we're actually allowed to say
🇨🇦 Health Canada
✓ Permitted: Helps to temporarily promote relaxation.
How to use it
As a capsule, or naturally from green tea.
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L-Theanine isn't in stock yet. Tell us you'd like it and we'll consider adding it.
Request L-Theanine →Side effects & safety
Generally well tolerated. Check with a practitioner if pregnant, breastfeeding, or taking medication.
A note on how to read this page. Traditional (TCM / Ayurveda) and holistic notes are cultural and historical context, offered for education — not medical advice or health claims. Health Canada's permitted claims reflect what regulators have assessed. Emerging research is early, and not a promise of results. Nothing here is intended to diagnose, treat, cure or prevent any disease. Always talk to your (or your pet's) health professional before starting a supplement.