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 · Last updated: Aug 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 Verified Source
Non-GMO Project Verified Verified

Transparency

3 claims
Third Party Testing Claim — Claimed Source
In House Testing — Verified Source
Contains Proprietary Blend — True
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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 with 2 verified certifications including Fda Gmp Inspections, Non-GMO Project Verified.

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?

Source Naturals L-Theanine, 200 mg has been analyzed for ingredient safety across all its components. All 4 inactive ingredients — including capsule materials, fillers, and binders — are rated safe based on regulatory data and published safety research. This is a clean formulation with no controversial additives. 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. They hold 2 verified certifications including Fda Gmp Inspections, Non-GMO Project Verified. Third-party certifications are independently verified and indicate the brand meets specific quality, purity, and manufacturing standards. No regulatory violations or FDA warning letters were found in our research.

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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.