What is a Certificate of Analysis?
A Certificate of Analysis (COA) is an authenticated document issued by a testing laboratory that confirms the identity, purity, and quality of a specific lot of a peptide. Unlike generic specification sheets, a lot-specific COA ties analytical data directly to the batch you receive.
Key fields to look for
Every credible COA should include: the peptide name and CAS number, the specific lot or batch number, the purity percentage determined by HPLC, the molecular weight confirmed via mass spectrometry, the date of analysis, the identity of the testing laboratory, and any relevant accreditation (such as ISO 17025).
Generic vs. lot-specific COAs
A generic COA uses data from one representative batch and applies it to all future lots — meaning the certificate you receive may not reflect the actual peptide in your vial. A lot-specific COA is generated for each individual batch, ensuring the data matches exactly what was shipped to you.
How to verify authenticity
Check that the lot number on the COA matches the lot number on your product label. Confirm the testing lab is independently accredited. Look for specific chromatogram references rather than rounded or suspiciously consistent numbers across multiple lots.