Home/ Supplements/ L Theanine/ L-Theanine 400 mg

L-Theanine 400 mg

product on market Capsule Mental Refreshment Safety: 100/100
100/100

This product looks safe

  • No ingredients exceed tolerable upper intake levels
  • 100% of ingredients have research evidence
A Label Compliance Grade

What the Evidence Says

AI-generated · Qwen 3.6 · grounded in 1 source · methodology

L-theanine is supported by moderate evidence for its ability to promote relaxation and reduce stress without causing sedation. Research indicates it may improve focus and cognitive function when paired with caffeine. The ingredient profile maintains a high safety rating for general use.

AI-generated summary based on research evidence. Not medical advice.

Label

Product Label

Label for L-Theanine 400 mg
Open Full PDF View on NIH DSLD →
Details

Label Data

2 Capsule(s)
Serving Size
90
Servings
Non-Nutrient/Non-Botanical
Product Type
100%
Evidence Coverage
Ingredients

Supplement Facts — Evidence Check

400 mg
Market median: 200.0mg (358 products) 9 studies (A:0, B:2)

Other Ingredients

Gelatin Rice powder
Claims

Label Claims — Verification

Unverified All Other
Unverified Structure/Function
Info

Product Information

Directions for Use

Directions: For adults, take two (2) capsules daily before a meal. As a reminder, discuss the supplements and medications you take with your health care providers.

Warnings & Precautions

Keep out of reach of children.

Warning: If you are pregnant, nursing or taking any medications, consult your doctor before use.

Discontinue use and consult your doctor if any adverse reactions occur.

Formulation Notes

Maximum strength Boosts cognition and mental performance Supports cardiovascular function Promotes relaxation - Calms the mind

Contains No: Artificial coloring, artificial flavor, preservatives, yeast, corn, milk or milk derivatives, lactose, salt, sodium, soy, sugar, gluten, starch or wheat.

Guaranteed Laboratory Tested Quality

We have assayed & fully guarantee the quality & potency of this product.

Additional Information

Premium Brand / Optimum Results

Store in a dry place and avoid excessive heat.

Manufactured in a FDA Registered facility that conforms to GMP standards GMP Good Manufacturing Practice Consistent Quality Made in the USA

100% Satisfaction Guaranteed

Metadata

Product Details

UPC / SKU7 15854 66471 0
DSLD Entry Date2021-04-22
Product TypeNon-Nutrient/Non-Botanical
FormCapsule
DSLD ID247845
Data Updated2026-04-11
Research

Research Evidence

37
Research Sources
53
Avg Quality
22
Rct
10
Systematic Review
3
Meta Analysis
1
Clinical Trial
1
Openfda Safety
B Examining the effect of L-theanine on sleep: a systematic review of dietary supplementation trials
Systematic Review Nutritional neuroscience 2026 PubMed DOI
B The effects of L-theanine consumption on sleep outcomes: A systematic review and meta-analysis
Meta Analysis Sleep medicine reviews 2025 PubMed DOI
B The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness
Rct Nutritional neuroscience 2010 PubMed DOI
B Effects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial
Rct Nutrients 2019 PubMed DOI
B The Role of Supplements and Over-the-Counter Products to Improve Sleep in Children: A Systematic Review
Systematic Review International journal of molecular sciences 2023 PubMed DOI
B Effects 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 Review and Meta-Analysis of Randomized Controlled Trials
Meta Analysis Nutrition reviews 2025 PubMed DOI
B Effect of Alpha-S1-Casein Tryptic Hydrolysate and L-Theanine on Poor Sleep Quality: A Double Blind, Randomized Placebo-Controlled Crossover Trial
Rct Nutrients 2022 PubMed DOI
B Effect of L-theanine on selective attention in a traffic-related reaction task in sleep-deprived young adults: a double-blind placebo-controlled, crossover study
Rct Nutritional neuroscience 2025 PubMed DOI
B The combined effects of L-theanine and caffeine on cognitive performance and mood
Rct Nutritional neuroscience 2008 PubMed DOI
B Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis
Meta Analysis Nutrition reviews 2014 PubMed DOI
View all evidence for L Theanine →
Compare

Similar Products

View all L Theanine products →

This product page is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before taking any supplement.