What it is: L-Theanine is a vegetarian, single-ingredient relaxation and stress support formula developed by DaVinci Labs, delivering 200 mg of Suntheanine® brand L-Theanine per capsule — a patented, pharmaceutical-grade, enzymatically synthesized form of pure L-theanine licensed by Taiyo International, Inc. and representing the most extensively researched L-theanine ingredient available. Unlike L-theanine derived from green tea extract, Suntheanine® is produced through a proprietary enzymatic fermentation process yielding a structurally pure L-isomer identical to the naturally occurring compound in green tea, with a peer-reviewed clinical research portfolio spanning stress reduction, relaxation, sleep quality, cognitive performance, and cardiovascular support. Designed for practitioner-directed use in stress management, relaxation, and sleep support protocols, this formula is appropriate for daily use or as-needed situational relaxation support without causing drowsiness or sedation.
How it works: L-Theanine supports relaxation, cognitive clarity, and neurological balance through several well-characterized central nervous system mechanisms. As a glutamic acid derivative and structural analog of glutamate — a primary excitatory neurotransmitter — L-Theanine crosses the blood-brain barrier and modulates glutamate receptor activity, attenuating excitatory neuronal signaling associated with stress and hyperarousal without producing sedation. Its most recognized neurological mechanism is the direct stimulation of alpha-wave brain activity — the neural oscillation pattern associated with a state of relaxed, alert wakefulness — producing a calm mental state that supports concentration and focus simultaneously, a dual neurological effect not shared by sedative compounds. L-Theanine additionally supports the endogenous production of inhibitory and mood-regulating neurotransmitters including GABA, dopamine, and tryptophan-derived serotonin, contributing to deep muscular relaxation, mood stabilization, reduced irritability, and improved sleep quality without daytime drowsiness. On the cardiovascular level, L-Theanine has been shown to support healthy blood pressure regulation within normal ranges through its modulation of sympathetic nervous system activity and nitric oxide-mediated vasodilation, providing complementary cardiovascular benefit alongside its central nervous system activity.
When to use it: L-Theanine (Suntheanine®) is appropriate for practitioner-directed use in adult clients requiring nutritional support for stress management, situational anxiety, irritability, cognitive focus under stress, sleep quality, and healthy blood pressure regulation within normal ranges. It is particularly well-suited for integration into protocols addressing HPA axis dysregulation, adrenal fatigue, stress-related sleep disruption, and cognitive performance under high-demand conditions, as well as for clients seeking non-sedating relaxation support that preserves daytime alertness and mental clarity. The formula may be used daily for ongoing stress resilience or on an as-needed basis for situational relaxation support, with one capsule daily as the standard recommended dose or as directed by a healthcare practitioner.
Serving Size: 1 Capsule
Servings Per Container: 120
Suggested Use: As a dietary supplement, take 1 capsule daily, or as directed by your healthcare practitioner.
| Amount Per Serving | % Daily Value | |
| L-Theanine (Suntheanine® Brand) | 200 mg | * |
* Daily Value not established. Percent Daily Values are based on a 2,000-calorie diet.
Other Ingredients: Microcrystalline cellulose, vegetable cellulose (capsule), vegetarian leucine.
Caution: If pregnant or nursing, consult your healthcare practitioner before taking this product. Keep out of reach of children. Store in a cool, dry place. Color may vary due to natural ingredient variation.
✓ Gluten Free ✓ Vegetarian
Key Ingredients
L-Theanine (Suntheanine® Brand) — 200 mg Suntheanine® is a patented, pharmaceutical-grade L-theanine produced through a proprietary enzymatic fermentation process by Taiyo International, Inc. — yielding a structurally pure L-isomer identical to the naturally occurring compound in green tea, but at a purity and consistency not achievable through conventional tea extraction, and with an extensive peer-reviewed clinical research portfolio that specifically validates Suntheanine® (not generic green tea-derived L-theanine) for stress reduction, relaxation, sleep quality improvement, and cognitive performance support. As a glutamic acid derivative and partial glutamate receptor modulator, Suntheanine® crosses the blood-brain barrier to attenuate excitatory neural signaling associated with stress and hyperarousal, while simultaneously stimulating alpha-wave brain activity — the oscillation pattern associated with relaxed, focused wakefulness — producing a unique dual state of calm mental clarity without sedation or cognitive impairment. At 200 mg per capsule, Suntheanine® supports endogenous production of GABA, dopamine, and serotonin precursors, promotes deep muscular relaxation, helps regulate healthy blood pressure within normal ranges through sympathetic nervous system modulation, and provides a clinically validated, non-habit-forming option for daily stress resilience and situational relaxation support in practitioner-directed protocols.
