L-Theanine
γ-Glutamylethylamide
Amino acid from green tea; promotes calm focus without sedation. No FDA RDI; declared with † symbol. Typical dose 100-200 mg per day.
FDA Reference Data
About L-Theanine
L-Theanine is a non-protein amino acid found naturally in green tea (Camellia sinensis) that crosses the blood-brain barrier and promotes alpha-wave brain activity associated with relaxed focus. As a non-essential amino acid, it has no FDA-established RDI and is declared with the † symbol. Typical doses are 100-200 mg per day. Often paired with caffeine (100 mg L-theanine + 50 mg caffeine = "smart stack") for focus without jitters.
Common Supplement Forms
Frequently Asked Questions
How do I declare L-Theanine on a Supplement Facts label?
Declare as "L-Theanine [amount] mg†" with the † symbol indicating no established Daily Value. The legend "Daily Value not established" must appear at the bottom of the Supplement Facts panel. Amounts are typically 100-200 mg per serving. If using Suntheanine®, the form may be noted in parentheses: "L-Theanine (as Suntheanine®) [amount] mg†".
What is the L-Theanine + Caffeine "smart stack"?
The combination of 100-200 mg L-Theanine with 50-100 mg caffeine is widely studied for promoting calm, sustained focus without the jittery effects of caffeine alone. L-Theanine modulates caffeine's effects by promoting alpha-wave brain activity. This ratio is common in nootropic and productivity supplements.
Is L-Theanine a sedative?
No. L-Theanine promotes relaxed focus (alpha-wave brain activity) without sedation. It does not impair cognitive performance or cause drowsiness at typical doses (100-200 mg). For sleep formulations, it is often paired with melatonin or magnesium rather than used as a standalone sleep aid.
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Building a supplement with L-Theanine?
ReguSift extracts ingredients from your COA, calculates %DV, formats proprietary blends, and generates a print-ready Supplement Facts label — including L-Theanine auto-formatted per FDA 21 CFR 101.36.