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The Independent Rating System

Vendors don't pay for placement here.The Score is the Score.

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Ranked Vendors

Global leaders in research peptides

Smart Searchfind vendors by peptide or compound

Summer Sale! 30% off sitewide + 15% with coupon PEPSCORES. Save up to 58% total with tiered rewards discount. Best testing protocol in the industry!
Elite Vendor
99.2
SCORE

Southern Aminos

United States
High Purity
Verified Labs
Endotoxin Tested
Elite
+3
3rd-Party TestedCards
Freedom Diagnostics (HPLC-UV + LCMS/MS: Purity, Identity, Net Peptide Content) + ILS Labs (ISO/IEC 17025) Full QC Panel (HPLC, ICP-MS, PCR Sterility, Endotoxin, Heavy Metals, Conformity, Fentanyl).
Purity
100.0
Reputation
99.0
Service
100.0
Shipping
99.0
Value
96.0
Selection
99.0

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Flawless Compounds - 30% off sitewide + 15% with coupon PEPSCORES
Elite Vendor
98.9
SCORE

Flawless Compounds

United States
High Purity
Fast Shipping
Community Fav
Endotoxin Tested
+2
3rd-Party TestedCards
ILS Labs (ISO/IEC 17025) Full QC Panel: HPLC Purity (99.81–99.86%), Identity, PCR Sterility, Endotoxin (USP <85>), Heavy Metals (ICP-MS), Net Peptide Content, 3-Sample Conformity, Fentanyl Screen. Freedom Diagnostics HPLC-UV + LCMS/MS for select products.
Purity
99.0
Reputation
98.0
Service
100.0
Shipping
100.0
Value
97.0
Selection
99.0

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Glow Aminos - Sale! 30% off sitewide +15% with coupon PEPSCORES
Elite Vendor
98.9
SCORE

Glow Aminos

United States
High Purity
Verified Labs
Fast Shipping
Rising Star
+4
3rd-Party TestedCards
ILS Labs (ISO/IEC 17025) Full QC Panel: HPLC Purity (99.29–99.96%), Identity, PCR Sterility, Endotoxin (USP <85>), Heavy Metals (ICP-MS), Net Peptide Content, Conformity, Fentanyl Screen.
Purity
99.0
Reputation
98.0
Service
100.0
Shipping
100.0
Value
97.0
Selection
99.0

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Elite Vendor
98.6
SCORE

Ion Peptides

United States
Top Quality
High Purity
Verified Labs
Fast Shipping
3rd-Party TestedCardsAlt
ILS Labs (ISO/IEC 17025) Full QC Panel: HPLC Purity, Identity, PCR Sterility, Endotoxin (USP <85>), Heavy Metals (ICP-MS), Net Peptide Content, Conformity. Freedom Diagnostics HPLC-UV + LCMS/MS for select products.
Purity
99.0
Reputation
99.0
Service
99.0
Shipping
99.0
Value
94.0
Selection
100.0

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EZ Peptides - 25% off sitewide + 10% with coupon code pepscores.
Elite Vendor
98.5
SCORE

EZ Peptides

United States
High Purity
Verified Labs
Fast Shipping
3rd-Party TestedCards
Every batch is third-party tested by Janoshik, the independent lab researchers trust, confirming identity, purity, and composition — with COAs available for every product.
Purity
99.0
Reputation
99.0
Service
99.0
Shipping
97.0
Value
96.0
Selection
100.0

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Only 25 of 61 evaluated peptide suppliers currently meet PeptideScores verification standards.

Vendor links may be affiliate links — this does not affect vendor rankings or scores. Rankings are determined solely by our independent scoring methodology.

Elite Vendor
98.3
SCORE

GenPeptide

United States
Verified Labs
High Purity
Domestic
Fast Shipping
3rd-Party TestedCardsCryptoAlt
Triple-Lab Verified: Kovera Labs (RP-HPLC, LC-MS, Endotoxin, Sterility, Heavy Metals, Batch Conformity), Freedom Diagnostics (HPLC-UV + LCMS/MS), Chromate Labs (HPLC, Identity). Purity 99.98% (Kovera). Traceable by SKU & report #.
Purity
100.0
Reputation
97.0
Service
100.0
Shipping
99.0
Value
98.0
Selection
92.0

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Elite Vendor
98.0
SCORE

Ascension Peptides

United States
High Purity
Verified Labs
Top Rated
Community Fav
3rd-Party TestedCardsAlt
Third-Party Tested for 99%+ Purity, Verified Potency, and Contaminant-Free Results — Every Batch, Multiple Stages

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Elite Vendor
97.9
SCORE

LA Peptides

United States
Verified Labs
High Purity
Domestic
Endotoxin Tested
3rd-Party TestedCards
Freedom Diagnostics HPLC-UV + LCMS/MS: Purity, Identity, Net Peptide Content. COA's searchable by accession # at FreedomDiagnosticsTesting.com.

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Elite Vendor
97.8
SCORE

FITSKNS

United States
High Trust
Community Fav
Top Quality
Verified Labs
+2
CardsAlt
Dual-Lab Verified: ILS Labs (ISO/IEC 17025) Full QC Panel (HPLC, ICP-MS, PCR Sterility, Endotoxin, Identity, Heavy Metals, Net Peptide Content, Conformity) + Freedom Diagnostics HPLC-UV/LCMS/MS.

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Elite Vendor
96.7
SCORE

Step One Ventures

United States
Transparent
Best Value
Fast Shipping
Domestic
+2
3rd-Party TestedCardsAlt
QR-Linked COA on Every Vial — Freedom Diagnostics or ILS Labs Verified. 99%+ Purity, Endotoxin-Screened, USA-Made.

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Elite Vendor
96.7
SCORE

IDUN Peptides

Est. 2026United States
Verified Labs
High Purity
New Entry
Rising Star
3rd-Party TestedCardsCryptoAlt
Every batch is HPLC-purified to ≥99% and identity-confirmed by mass spectrometry, shipping with a full Certificate of Analysis — with published chromatograms, MS results, and an open CoA library for any batch

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Elite Vendor
96.6
SCORE

Limitless Life

United States
Verified Labs
Specialist
Legacy Brand
Rare Peptides
3rd-Party TestedCardsCryptoAlt
Every Batch Screened Across HPLC, LC-MS, Sterility & Endotoxin Panels — ≥99% Purity Spec, USA-Made, COA With Every Order.

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Elite Vendor
95.9
SCORE

Crownwell Research

Est. 2026United States
Budget King
Transparent
Best Value
Domestic
+1
3rd-Party TestedCardsAlt
Independently Verified for Purity, Molecular Identity & Batch-to-Batch Consistency — 99% Standard, COA's available on roughly 1/2 of the inventory

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Elite Vendor
93.8
SCORE

Core Peptides

United States
Verified Labs
Rare Peptides
Specialist
3rd-Party TestedCardsAlt
Third-Party Verified by Vanguard Scientific Laboratory — HPLC ≥99% Purity, Mass-Spec Identity, Lot-Specific COA on Every Product Page.
93.2
SCORE

Umbrella Labs

United States
Verified Labs
3rd-Party TestedCryptoAlt
Independent Third-Party COAs on Every Product Page — HPLC Purity & MS Identity, Verified by Credentialed Chemists. Guaranteed 99%+ Purity, USA-Domestic.