How to Compare Peptide Suppliers Side by Side

Certificate of Analysis Availability: does every batch have a batch-specific COA? Are raw data (chromatograms, spectra) provided? Third-Party Testing: is testing done by independent labs or in-house? Are results verifiable?

Manufacturing Transparency: do they disclose synthesis method, facility location, quality-assurance procedures? Support Clarity: how quickly and thoroughly do they answer technical questions? Refund Clarity: what is their returns and refund policy? Affiliate Disclosure: are they transparent about financial incentives or conflicts of interest?

For each criterion, assess on a scale: Full transparency / Partial transparency / No transparency. Suppliers with full transparency across all six are higher confidence. Those with significant gaps may be lower confidence.

Weight your assessment based on what matters most to your research needs.

If a supplier refuses to provide batch-level documentation, reconsider. If they make therapeutic or dosing claims, they are operating outside research-use supply. If they demand crypto payment, avoid.

Create a spreadsheet listing each supplier and scoring each of the six criteria. Add any additional criteria relevant to your needs (price, turnaround time, specific peptide availability). This visual comparison makes the trade-offs clear.