Does a certificate of analysis guarantee a peptide is pure?

No, on two counts. First, a certificate published by the seller is a PDF they chose to upload, which is different from a laboratory's own portal confirming that exact report. Second, accreditation itself has limits: we found that one major peptide testing lab's ISO/IEC 17025 scope of accreditation, the actual document filed with its accreditor, does not include the HPLC purity test most buyers assume it covers. Read the scope, not just the logo.

Educational use only. This database summarizes published research and is not medical advice. Where a dose appears it is a record of what a trial or clinic ran, or what people describe doing, with its source attached. Nothing here is a recommendation for personal use.

Part of buying, vendors, and lab testing. How to evaluate a seller's claims, certificates of analysis, and pricing.