Is 200 mg of Suntheanine safe?

The recommended daily intake is None mg.

L-Theanine 200 mg by Metabolic Maintenance

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

Suntheanine is a patented form of L-theanine used to promote relaxation and reduce stress. There is strong evidence supporting its ability to lower anxiety and improve cognitive focus without causing sedation. This ingredient profile maintains a high safety rating for general consumption.

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

Label

Product Label

Open Full PDF View on NIH DSLD →

Details

Label Data

1 Capsule(s)

Serving Size

120

Servings

Non-Nutrient/Non-Botanical

Product Type

100%

Evidence Coverage

Ingredients

Supplement Facts — Evidence Check

Suntheanine

200 mg

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

Other Ingredients

Vegetarian Cellulose Capsule

Claims

Label Claims — Verification

Unverified All Other

Info

Product Information

Directions for Use

Directions: One (1) capsule daily, or as directed by a healthcare professional. Best taken between meals.

Warnings & Precautions

Caution: Pregnant or lactating women, consult your healthcare professional before taking this product.

Keep tightly closed in a cool, dry place, out of the reach of children.

Formulation Notes

Egg free Gluten free Free of nuts Dairy free

Manufactured in a GMP Compliant Facility

Additional Information

Keep tightly closed in a cool, dry place, out of the reach of children.

Metadata

Product Details

UPC / SKU8 38287 00147 8

DSLD Entry Date2022-10-24

Product TypeNon-Nutrient/Non-Botanical

FormCapsule

BrandMetabolic Maintenance

DSLD ID274319

Data Updated2026-04-11

Research

Research Evidence

Research Sources

Avg Quality

Rct

Systematic Review

Meta Analysis

Clinical Trial

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.