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L-Theanine 200 mg

product on market Tablet or Pill Source Naturals Serene Science Safety: 100/100
100/100

This product looks safe

  • No ingredients exceed tolerable upper intake levels
  • 50% of ingredients have research evidence
A Label Compliance Grade

What the Evidence Says

AI-generated · Qwen 3.6 · methodology

L-theanine is supported by moderate evidence for promoting relaxation and reducing stress. Calcium is a well-established mineral essential for bone health and cellular signaling. Research indicates these ingredients are generally safe for consumption.

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 Tablet(s)
Serving Size
60
Servings
Other Combinations
Product Type
50%
Evidence Coverage
Ingredients

Supplement Facts — Evidence Check

Calcium
77 mg (6% DV)
Market median: 200.0mg (358 products) 9 studies (A:0, B:2)

Other Ingredients

Dibasic Calcium Phosphate Microcrystalline Cellulose Magnesium Stearate Stearic Acid Silica modified Cellulose Gum Hydroxypropyl Cellulose
Claims

Label Claims — Verification

Unverified Nutrient
Unverified All Other
Unverified Structure/Function
Info

Product Information

Directions for Use

Suggested Use: 1 tablet 1 to 2 times daily.

Warnings & Precautions

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

Keep out of the reach of children.

Warning: Not for use by children or women who are pregnant, may become pregnant, or breastfeeding.

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

Formulation Notes

Made with Suntheanine

Focused relaxation

Non GMO Validated

L-Theanine is an amino acid that preliminary evidence suggests may help ease some psychological and physical aspects of normal everyday stress, including occasional anxiety and tension. 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.

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

Metadata

Product Details

UPC / SKU0 21078 01499 7
DSLD Entry Date2023-01-23
Product TypeOther Combinations
FormTablet or Pill
DSLD ID273221
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 →
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This product page is for informational purposes only and does not constitute medical advice. Always consult your healthcare provider before taking any supplement.