How to read a peptide certificate of analysis
5 Oct 2026
A certificate of analysis (COA) is a lab report on a specific batch. A good one lets you check that what you received is what the shop says it is.
What a useful COA shows
- The testing lab's name, ideally independent of the shop, with a way to verify the report on the lab's own site.
- A batch or lot number that matches the label on your vial.
- The test date, recent enough to be relevant to the stock being sold.
- Identity, usually by mass spectrometry (MS), confirming the molecule is the one named.
- Purity, usually by HPLC, given as a percentage.
- Quantity, the measured mg in the vial compared with the label.
Warning signs
- No batch number, or one that never changes.
- The same report used for several products or sizes.
- “Available on request” only, with no published examples.
- Edited-looking PDFs, or a lab you cannot find.
On The Peptide Hub, the Trust Score gives up to 25 points for publishing batch reports. See how the Trust Score works.