Guide5 days ago 6 min read
How to read a peptide Certificate of Analysis (COA)
A line-by-line walkthrough of what each section actually tells you.
by Editorial team
What a COA is
A Certificate of Analysis is a lab report that documents what is actually in a vial and at what purity.
Good COAs come from an independent third-party lab, not the manufacturer itself.
Key sections
Identity confirms the peptide is what the label says — usually via mass spectrometry.
Purity is reported as a percentage, typically by HPLC; look for >98% on premium products.
Endotoxins and microbial testing matter for any injectable product.
Red flags
A COA with no lab name, no batch number, or unrealistic 100.0% purity should be treated with suspicion.
Watermarks and PDFs can be edited; cross-reference batch numbers when possible.