L-Theanine 200 mg®®

Non-Nutrient / Non-Botanical

Brand: Source Naturals Serene Science

CapsuleNon-Nutrient/Non-BotanicalOn Market

Functions

Sleep, Mood & Stress

Product label for L-Theanine 200 mg — Click to view full label

Net Contents

120 Capsule(s)

Serving Size

1 Capsule(s)

Servings Per Container

120

Supplement Form

Capsule

Bar Code (UPC/SKU)

0 21078 02427 9

Product Version

SN2427 REV E132

Label Analysis

Objective insights generated automatically from the official DSLD label — a quick, factual read of how this product is formulated and disclosed.

1Active Ingredients

Single-ingredient formula listed in Supplement Facts.

100%Amount Transparency

Every active ingredient discloses a specific amount per serving.

1Dietary Attributes

Label states: Gluten-Free.

This analysis is generated algorithmically from label data for educational reference only. It is not a product endorsement, ranking, or medical advice.

Allergen Guide

Contains

Milk
Egg
Wheat
Soy
Gluten

Allergen flags are parsed automatically from the official label's claims and statements. Always verify against the physical product label before use, especially if you have a severe allergy.

Supplement Facts

Serving Size: 1 Capsule(s) · 1–2 per day

Ingredient	Amount Per Serving
L-Theanine	200 mg	—

Not Present

Other Ingredients

Microcrystalline CelluloseGelatinSilicaMagnesium Stearate

Target Groups

Adult (18 - 50 Years)Women (not pregnant or lactating)Gluten FreeDairy FreeSugar Free

Label Claims

NutrientAll OtherStructure/Function

Directions & Suggested Use

Suggested/Recommended/Usage/Directions

Suggested Use: 1 capsule 1 to 2 times daily.

Warnings & Precautions

Precautions re: Children

Warning: Not for use by infants, children, or women who are pregnant, may become pregnant, or breast feeding. Keep out of the reach of children.

Precautions re: Pregnant or Nursing or Prescription Medications

Warning: Not for use by infants, children, or women who are pregnant, may become pregnant, or breast feeding. If you are taking any antidepressant drugs, such as MAOIs or SSRIs, consult your health care professional before taking this product.

Precautions re: All Other

Do not use if either tamper-evident seal is broken or missing.

Formulation

Formulation re: Other

Focused relaxation

Formula re: Contains

L-Theanine is a unique amino acid found almost exclusively in the tea plant (Camellia sinensis) and contributes to the unusual taste of green tea. Human studies have shown that taking L-theanine affects the emission of alpha waves in the brain associated with states of relaxation and focused attention. Preliminary research has shown that L-theanine crosses the blood brain barrier, and suggests that it may support healthy neurotransmitter levels in the brain, and inhibit the stimulatory properties of caffeine.

Formulation re: Does NOT Contain

Hypoallergenic: contains no yeast, dairy, egg, gluten, corn, soy or wheat. Contains no sugar, starch, salt, preservatives, or artificial color, flavor or fragrance.

Formulation re: Other

Hypoallergenic: contains no yeast, dairy, egg, gluten, corn, soy or wheat.

FDA Statements

FDA Statement of Identity

Dietary Supplement

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Other Label Statements

Brand IP Statement(s) re: (c), (TM), (SM)

Manufacturer & Distributor

Distributor

Source Naturals, Inc.

P. O. Box 2118, Santa Cruz, CA, 95062

Market Reference

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$16.99
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$48.29
Serene
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$43.00
Caffeine + L-Theanine Source Naturals
Herbs Direct4.7(30)
$9.76

Where to Buy Locally

Enter your city or ZIP code to find supplement & health stores in your area that may carry this product.

Showing representative supplement & health retailers — search above for stores in your area.

The Vitamin Shoppe
4.3 (184)
Vitamin & supplements store
12 4th Ave, Brooklyn, NY 11217
Directions (718) 858-8314
GNC
4.2 (280)
Vitamin & supplements store
134-136 Fulton St, New York, NY 10038
Directions (212) 374-9473
GNC
4.4 (92)
Vitamin & supplements store
753 Broadway Spc 753, New York, NY 10003
Directions (212) 380-5999
Pure Essentials Supplements
5.0 (2)
Vitamin & supplements store
121 Varick St, New York, NY 10013
Directions (212) 758-3200
The Vitamin Shoppe
3.9 (85)
Vitamin & supplements store
32 Court St, Brooklyn, NY 11201
Directions (718) 596-0466
GNC
4.7 (202)
Vitamin & supplements store
2 Pennsylvania Plaza Ste 29B, New York, NY 10121
Directions (212) 239-1251
GNC
3.7 (106)
Vitamin & supplements store
2 Broadway, New York, NY 10004
Directions (212) 514-5770
The Vitamin Shoppe
4.4 (171)
Vitamin & supplements store
385 5th Ave, New York, NY 10016
Directions (212) 532-4534

Research & Studies

Safety and Efficacy of AlphaWave®l-Theanine Supplementation for 28 Days in Healthy Adults with Moderate Stress: A Randomized, Double-Blind, Placebo …
M Moulin, DC Crowley, L Xiong, N Guthrie… - Neurology and …, 2024 - Springer
… study that showed supplementation with l-theanine (200 mg/day) for four weeks in healthy adults significantly … Moreover, l-theanine supplementation (400 mg/day) for 17 days in …
202427 citations
L-theanine, unique amino acid of tea, and its metabolism, health effects, and safety
D Türközü, N Şanlier - Critical reviews in food science and nutrition, 2017 - Taylor & Francis
… Similarly, instead of 50 mg, 200 mg L-theanine caused increase in the … L-theanine (200 mg), caffeine (100 mg) or placebo and at the end of the study it was found out that L-theanine …
2017250 citations
L-Theanine for Dissociation: Promoting Calm and Presence
TY Order, USD Australia, EUR Finland, EUR France… - moodriselabs.com
… L-theanine has been shown to lower cortisol levels in stressful situations. In clinical studies, participants who took 200 mg of L-theanine … a key marker of vagal health. As HRV improves, …
A Randomized, Triple-Blind, Placebo-Controlled, Crossover Study to Investigate the Efficacy of a Single Dose of AlphaWave®l-Theanine on Stress in a Healthy Adult …
M Evans, AC McDonald, L Xiong, DC Crowley… - Neurology and …, 2021 - Springer
… In this study, participants were administered a 200 mg single dose of AlphaWave ® l-Theanine, and the response to an acute stress model was investigated; thus, the efficacy of long-…
202149 citations
L-Theanine, the Magic of Green Tea
A Snow - Prevention, 2021 - camdenwholehealth.com
… Enter the natural supplement. Capsules of l-theanine at the 200 mg daily dose are available at Emerson Ecologics, and here at the pharmacy at Camden Whole Health. Ask your holistic …
2021
… of Tea (Camellia sinensis) or its Bioactive Compounds l-Theanine or l-Theanine plus Caffeine on Cognition, Sleep, and Mood in Healthy Participants: A Systematic …
ER Payne, M Aceves-Martins, J Dubost… - Nutrition …, 2025 - academic.oup.com
… In theanine-only, low-caffeine, or caffeine-free interventions, the median theanine dose was 200 mg (IQR, 100.45-212.5). Industry was the most common funding source (n = 8), followed …
202514 citations

Data sourced from the U.S. National Institutes of Health, Office of Dietary Supplements Dietary Supplement Label Database (DSLD) · Label entered 2023-08-23. DSLD Label ID: 295953. This information is provided for educational reference only and is not medical advice. Always follow the product label and consult a doctor or pharmacist before use.