Natural Factors Stress-Relax, Suntheanine L-Theanine, 100 mg, 120 Chewable Tablets supplement bottle
Natural Factors

Stress-Relax, Suntheanine L-Theanine, 100 mg, 120 Chewable Tablets

What We Researched
5 active ingredients analyzed · 7 inactive ingredients decoded · 5 brand certifications checked · 3 retailers compared · Last updated: Mar 2026
95
Product Score Excellent
88
Brand Score Good

Product Analysis

Transparency Very Good

Supplement Facts

IngredientAmount% DV
Suntheanine®L-Theanine 200 mg **
Bioavailability Excellent

Absorption Rating

  • Suntheanine®L-Theanine Good
Other Ingredients Excellent

Fillers & Additives

  • Organic Cane Sugar
  • Xylitol
  • Stearic Acid
  • Silica
  • Natural tropical flavor
  • Citric Acid
  • Magnesium Stearate (Vegetable Grade)
Efficacy Excellent

Dosage Analysis

  • Suntheanine®L-Theanine 200 mg Effective

Supplement Facts

Ingredient Amount % Daily Value
Calories 15
Total Carbohydrate 4 g 1%‡
Total Sugars 3 g **
Includes 3 g Added Sugars 6%‡
Suntheanine®L-Theanine 200 mg **

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Organic Cane Sugar Safe

Adds sweetness and helps create gummy texture.

Xylitol Safe

Provides sweetness with reduced calorie content. Does not promote tooth decay.

Stearic Acid Safe

Helps ingredients flow smoothly through manufacturing equipment.

Silica Safe

Prevents ingredients from clumping and improves powder flow.

Natural tropical flavor Unknown
Citric Acid Safe

Adds tartness and acts as a natural preservative. Also aids in ingredient stability.

Magnesium Stearate (Vegetable Grade) Generally_safe

It is used to prevent ingredients from sticking to manufacturing equipment.

Price Comparison

iHerb $35.67 $0.59 / serving
Best Price
Target $37.99 $0.63 / serving

Price History

Tracked across major retailers. Updated periodically.

$38$37$36$35$34 Mar 12 $35.67
iHerb

Prices shown at time of last check. Click a retailer to see current price. GoodSupp is not affiliated with any retailer.

Brand Trust Report
Natural Factors

Founded 1950 · Coquitlam, British Columbia, Canada · 390 products · naturalfactors.com

Certifications

5 certifications
B Corp Certified Verified Source
Usp Verified Verified Source
Fda Gmp Inspections Verified Source
Non Gmo Project Verified Source
Usda Organic Verified Source

Transparency

4 claims
Third Party Testing Claim — Verified Source
Testing Lab Disclosure — Verified Source
In House Testing — Verified Source

Violation History

5 incidents
Prop 65 Lead2025-10-31Source
Recall Hi Potency B Complex, RevitalX, Super Multi® IRON FREE2024-07-19Source
Lawsuit Products labeled as containing glucosamine sulfate did not contain the ingredient.2021Source
Prop 65 Lead2016-01-13Source
Recall Natural Factors L-Arginine 500mg2006-04-05Source
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Frequently Asked Questions
Is Natural Factors Stress-Relax, Suntheanine L-Theanine a good supplement?

Natural Factors Stress-Relax, Suntheanine L-Theanine, 100 mg, 120 Chewable Tablets received a product quality score of 95/100 in GoodSupp's independent analysis, placing it in the top tier of supplements we've analyzed. The product contains 5 active ingredients with 60 servings per container. Of the 7 inactive ingredients, 5 are rated safe and 0 are flagged for review. The manufacturer, Natural Factors, holds a brand trust score of 88/100 with 5 verified certifications including B Corp Certified, Usp Verified, Fda Gmp Inspections, Non Gmo Project.

What are the ingredients in Natural Factors Stress-Relax, Suntheanine L-Theanine?

Natural Factors Stress-Relax, Suntheanine L-Theanine contains 5 active ingredients: Calories (15), Total Carbohydrate (4 g), Total Sugars (3 g), Includes 3 g Added Sugars, Suntheanine®L-Theanine (200 mg). Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Natural Factors Stress-Relax, Suntheanine L-Theanine safe to take?

Natural Factors Stress-Relax, Suntheanine L-Theanine, 100 mg, 120 Chewable Tablets has been analyzed for ingredient safety across all its components. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Is Natural Factors a trustworthy supplement brand?

Natural Factors receives a brand trust score of 88/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1950 and headquartered in Coquitlam, British Columbia, Canada, the company offers 390 products in their lineup. They hold 5 verified certifications including B Corp Certified, Usp Verified, Fda Gmp Inspections, Non Gmo Project. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. Note: Natural Factors has 5 historical regulatory incidents on record, which are factored into the trust score.

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Disclaimer: GoodSupp provides independent supplement quality analysis for informational purposes only. Scores are generated algorithmically based on ingredient profiles, brand certifications, and public records. This is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Product data is sourced from manufacturer labels and public databases. GoodSupp is not affiliated with any supplement brand.