Does a certificate of analysis guarantee a peptide is pure?

No, for two reasons. First, a report posted by the seller is a PDF they chose to upload. That is different from the lab's own website confirming that exact report. Second, lab accreditation has limits. We found that one major peptide testing lab's ISO/IEC 17025 accreditation, the actual document filed with the body that accredits it, does not include the HPLC purity test most buyers assume it covers. Read what the accreditation covers, 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.