How to read a certificate
A COA is a lab's statement about one specific batch. These are the fields that matter and what each one actually tells you.
The percentage of the sample that is the target compound, measured by high-performance liquid chromatography. The number to check first.
Mass spectrometry confirms the observed molecular mass matches the theoretical mass. Purity without identity is meaningless — you want both.
How much of the vial's net weight is actual peptide versus counter-ions and residual water. Often lower than the purity figure — that's expected.
Measured by Karl Fischer titration. High residual moisture shortens shelf life in a lyophilized product.
The certificate applies to that lot only. If the lot on your vial doesn't match the lot on the paperwork, the paperwork is not yours.
A named analyst and lab, not just a logo. An unsigned certificate from an unnamed source is a marketing graphic.
What a certificate is not
A certificate of analysis describes the identity and purity of the lot tested, by the methods referenced. It is not approval by any regulatory body, not a safety assessment, and not a statement that the material is fit for any particular application. Products are sold for laboratory research use only — see the full Disclaimer.