What a real COA tells you — and what might be hiding in your peptides.
A Certificate of Analysis is only as good as the lab that issued it. Here is how to read one, which labs to trust, what to look for, and what contaminants are actually found in substandard peptides.
- A COA is only as trustworthy as the independent lab that issued it — manufacturer self-tests prove batch consistency, not purity.
- HPLC measures purity but cannot confirm identity; LC-MS (mass spec) is what catches deliberate mislabeling.
- A complete COA shows identity, purity percentage, and an actual assay value in mg — not just one number.
- Verify the result on the lab's own server; a PDF alone is trivial to fabricate, and COAs over 12 months are treated as expired.
What is a COA?
A Certificate of Analysis (COA) is a document issued by an analytical laboratory confirming the composition and purity of a batch of product. For research peptides, a proper COA should include: identity confirmation (HPLC, LC-MS), purity percentage, actual assay content (mass in mg vs nominal), and ideally endotoxin and heavy metal testing.
COA red flags — how to spot a fake or weak COA
Trusted independent labs
What contaminants are actually found?
Every COA in our database is reviewed by our team. We verify the lab, check the batch date, confirm the assay value exists, and flag any COA older than 12 months as expired. COA purity contributes 35% to our ranking score — it's the second-most important factor after price.