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// Ranked
Current Rankings
Peptide Sciences
Editor's Choice$$$Consistently high purity scores across third-party testing. Strong COA documentation and US-based shipping. The benchmark for research-grade quality.
Pros
+ HPLC tested on every batch
+ Full COA available pre-purchase
+ US domestic shipping
+ 99%+ purity on most compounds
Cons
− Premium price point
− Limited selection vs competitors
Limitless Life Nootropics
Best Value$$Competitive pricing with reliable COA availability. Good selection of hard-to-source peptides. Strong community reputation for consistency.
Pros
+ Competitive pricing
+ Wide peptide selection
+ Responsive customer service
+ Frequent discount codes
Cons
− Shipping can be slower
− COA format varies by batch
Pure Rawz
Widest Selection$$Largest peptide catalog with frequent discounts. Purity scores are solid with room for improvement on batch consistency.
Pros
+ Largest catalog available
+ Frequent sales and promotions
+ Multiple payment options
+ Good for stacking compounds
Cons
− Purity consistency varies
− COA accessibility could improve
// Methodology
How We Test
Our testing methodology is designed to eliminate bias and provide the research community with reliable sourcing data.
Anonymous Purchase
We purchase peptides anonymously using team member accounts — vendors have no knowledge of our testing. Orders placed across different time periods to assess consistency.
Third-Party HPLC Analysis
All samples are sent to an independent analytical chemistry laboratory for HPLC-UV testing. We verify purity, identify impurities, and confirm compound identity via mass spectrometry.
COA Cross-Verification
Vendor-provided Certificates of Analysis are compared against our independent results. Discrepancies are flagged and factored into our transparency score.
Quarterly Re-Testing
Top-ranked vendors are re-tested quarterly. Rankings are updated when new data becomes available or when significant quality changes are detected.