Thea-Zen

product on market Capsule HBC Protocols 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

Theanine is supported by strong evidence for its ability to promote relaxation and reduce stress levels. Research indicates it may improve cognitive function and sleep quality by modulating neurotransmitters in the brain. The ingredient profile maintains a high safety rating based on available clinical data.

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

Label

Product Label

Label for Thea-Zen
Open Full PDF View on NIH DSLD →
Details

Label Data

1 Capsule(s)
Serving Size
240
Servings
Amino acid/Protein
Product Type
100%
Evidence Coverage
Ingredients

Supplement Facts — Evidence Check

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

Other Ingredients

Vitamin D Vitamin E Cyclodextrin Maltodextrin Magnesium Stearate
Claims

Label Claims — Verification

Unverified All Other
Unverified Structure/Function
Info

Product Information

Directions for Use

Because it has a mild taste, capsules may be opened and dissolved in water.

Suggested Use: Take 1 to 2 capsules per day with water or juice on an empty stomach, or as directed by your qualified health consultant.

Warnings & Precautions

Although it is probably safe for pregnant women and nursing mothers, we discourage its use by them pending conclusive research.

Caution: L-theanine enhances chemotherapy effects. If you are receiving chemotherapy, check with your doctor.

Formulation Notes

Theanine 99.7% Pure (Research Grade)

Additional Information

L-theanine, a unique free form amino acid found in green tea and various mushrooms, has been shown to increase tranquilizing alpha-waves without inducing drowsiness. Clinical studies have shown it to be effective in single doses of 100 to 200 mg 1 to 3 times daily or as needed depending on stress and anxiety levels. For those seeking a continuous mood eleveating effect, one capsule can be taken four times throughout the day. Based on the results of clinical studies, L-theanine is most effective in the range 50-200 mg, with the effect being felt within 30 minutes and lasting for 8-10 hours. Individuals with high stress levels may increase their dosage of L-theaning to at least 100 mg, with no more than 600 mg being taken in a six hour period. FDA recommends a maximum dose of 1200 mg daily, although the reason for this limit is not clear, due to its demonstrated safety. There are no known adverse reactions to L.theanine and no drug interactions have been reported. L-theanine is not affected by food and may be taken anytime, as needed.

Meditation in a Bottle

100% Kosher and Halal approved vegetable capsule.

Metadata

Product Details

UPC / SKU6 79840 87182 0
DSLD Entry Date2012-07-25
Product TypeAmino acid/Protein
FormCapsule
DSLD ID11370
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
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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.