Home/ Supplements/ L Theanine/ L-Theanine 200 mg

L-Theanine 200 mg

product on market Capsule Nutricost 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 to strong evidence for its ability to promote relaxation and reduce stress without causing sedation. Research indicates it may improve cognitive focus and attention when paired with caffeine. This ingredient is generally recognized as safe for most adults.

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

Label

Product Label

Label for L-Theanine 200 mg
Open Full PDF View on NIH DSLD →
Details

Label Data

1 Capsule(s)
Serving Size
240
Servings
Non-Nutrient/Non-Botanical
Product Type
100%
Evidence Coverage
Ingredients

Supplement Facts — Evidence Check

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

Other Ingredients

Rice Flour Gelatin Capsule
Claims

Label Claims — Verification

Unverified All Other
Unverified Structure/Function
Info

Product Information

Directions for Use

Recommended Use: As a dietary supplement, take 1 capsule 1-2 times daily with 8-12 oz of water, or as directed by your physician.

Warnings & Precautions

Warning: Consult your physician prior to use if you are pregnant or nursing.

Do not exceed recommended use.

Keep out of reach of children.

Do not use if safety seal is broken.

Formulation Notes

L-Theanine 200 mg per serving

Non GMO Gluten free product

Additional Information

Notice: Store in a cool, dry place.

Nutricost Quality guaranteed 3rd party tested

Metadata

Product Details

UPC / SKU7 02669 93491 6
DSLD Entry Date2020-06-24
Product TypeNon-Nutrient/Non-Botanical
FormCapsule
BrandNutricost
DSLD ID223413
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

L-Theanine
XYMOGEN · Capsule
100
L-Theanine
XYMOGEN · Capsule
100
Thea-Zen
HBC Protocols · Capsule
100
L-Theanine 100 mg
Newflower Farmers Markets · Capsule
100
L-Theanine 200 mg
Vitamin World · Capsule
100
View all L Theanine products →
L Theanine research Best L Theanine All L Theanine products More from Nutricost View on NIH DSLD →

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