How to Read a Peptide COA
A Certificate of Analysis is most useful when it is specific, traceable and complete. Here is a practical checklist you can use when reviewing supplier documentation.
1. Match the product and batch
The report should identify the material tested and ideally include a lot or batch identifier that can be matched to the supplier’s inventory or your vial.
2. Check the test method
HPLC is commonly used to report purity, while mass spectrometry can help confirm molecular identity. These methods answer different questions, so one headline percentage should not be treated as a complete quality assessment.
3. Check dates and laboratory identity
Look for sample receipt, analysis, or report dates and identify who performed the testing.
4. Understand what purity does not tell you
A high analytical purity result does not automatically establish sterility, endotoxin status, dose accuracy, clinical safety, or efficacy.
5. Prefer complete reports
Full report pages, method information and traceability are more useful than cropped certificates or marketing graphics.