Almost every research-peptide vendor will wave a “COA” at you as proof of quality. But a Certificate of Analysis is only worth anything if you know what it should contain — and what a real one looks like versus a screenshot someone typed up in a template. Here’s the whole thing in plain English.
What a real COA contains
A legitimate Certificate of Analysis ties a specific batch of product to specific test results. At minimum, it should show four things:
Purity without identity is meaningless
This is the trap most buyers fall into. A purity figure alone only tells you the sample is “pure something.” Without a mass-spec identity check, it doesn’t tell you the something is the peptide on the label. Always look for both HPLC purity and a mass-spec identity confirmation. One without the other is a half-answer.
The red flags
You can catch most fake or useless COAs in about thirty seconds. Here’s what to watch for:
| Red flag | Why it matters |
|---|---|
| No batch number | The COA can’t be tied to your vial — it could describe anything. |
| Purity, but no chromatogram | A number with no chart behind it is trivial to invent. |
| No mass-spec identity | You have no proof it’s actually the labeled compound. |
| Same COA on every product | A reused document isn’t testing — it’s decoration. |
| Batch number mismatch | If the paperwork and the vial disagree, trust the disagreement. |
Why we re-test
Because a COA is easy to screenshot, the only way to actually trust one is independent verification. That’s the standard we hold vendors to: we buy product anonymously, send it to a third-party lab, and a batch only earns a Verified badge when the results match the paperwork. Read more in what “Verified” means here.
For research use only. This article is educational and makes no health, dosing, or usage claims of any kind.