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Source Naturals L-Theanine, 200 mg supplement bottle
Source Naturals

L-Theanine, 200 mg Review

What We Researched
1 active ingredient analyzed · 4 inactive ingredients decoded · 2 brand certifications checked · Page generated: Sep 2026
100
Product Score Excellent
75
Brand Score Fair

Two independent scores — the product and the brand behind it, never blended into one number. See our methodology.

Product Analysis

Transparency Excellent

Supplement Facts

IngredientAmount% DV
L-Theanine (Suntheanine®) 200 mg †
Bioavailability Excellent

Absorption Rating

  • L-Theanine (Suntheanine®) Good
Other Ingredients Excellent

Fillers & Additives

  • Microcrystalline Cellulose
  • Gelatin (Capsule)
  • Silica
  • Magnesium Stearate
Efficacy Excellent

Dosage Analysis

  • L-Theanine (Suntheanine®) 200 mg Effective

Supplement Facts

Ingredient Amount % Daily Value
L-Theanine (Suntheanine®) 200 mg †

Other Ingredients

Inactive ingredients used in manufacturing. All rated for safety.

Microcrystalline Cellulose Safe

Adds bulk to small-dose supplements to make tablets/capsules a manageable size.

Gelatin (Capsule) Safe

It is used as a material for making capsules.

Silica Safe

Prevents ingredients from clumping and improves powder flow.

Magnesium Stearate Safe

Prevents ingredients from sticking to manufacturing equipment during tableting.

Brand Trust Report
Source Naturals

Founded 1982 · Scotts Valley, CA, USA · 1511 products · sourcenaturals.com/

Certifications

2 certifications
Fda Gmp Inspections Source available Primary evidence
Non-GMO Project Verified Supporting evidence unavailable

Transparency

3 claims
Third Party Testing Claim — Claimed Evidence available Evidence
In House Testing — Verified Evidence available Evidence
Contains Proprietary Blend — True Brand claim; evidence unavailable
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Frequently Asked Questions
Is Source Naturals L-Theanine, 200 mg a good supplement?

Source Naturals L-Theanine, 200 mg received a product quality score of 100/100 in GoodSupp's independent analysis, placing it in the top tier of supplements we've analyzed. The product contains 1 active ingredients All 4 inactive ingredients (fillers, binders, capsule materials) are rated safe — a clean formulation with no flagged additives. The manufacturer, Source Naturals, holds a brand trust score of 75/100.

What are the ingredients in Source Naturals L-Theanine, 200 mg?

Source Naturals L-Theanine, 200 mg contains 1 active ingredients: L-Theanine (Suntheanine®) (200 mg). Each ingredient's dosage, form, and safety rating is analyzed independently in GoodSupp's full product breakdown.

Is Source Naturals L-Theanine, 200 mg safe to take?

GoodSupp reviewed the inactive-ingredient data available for Source Naturals L-Theanine, 200 mg. All 4 inactive ingredients — including capsule materials, fillers, and binders — are currently classified as safe in GoodSupp's ingredient reference data. This label analysis cannot determine whether the product is safe for a particular person, and source labels may change. Always consult your healthcare provider before starting any new supplement, especially if you take medications or have underlying health conditions.

Is Source Naturals a trustworthy supplement brand?

Source Naturals receives a brand trust score of 75/100 based on GoodSupp's independent analysis of certifications, regulatory history, and transparency practices. Founded in 1982 and headquartered in Scotts Valley, CA, USA, the company offers 1511 products in their lineup.

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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 — read our methodology. 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.