How to Read a Peptide COA
Most people look at a COA and see numbers — without knowing what’s good, bad, or missing. This guide walks through every section so you can evaluate any peptide Certificate of Analysis with confidence.
The top of a legitimate COA should clearly state:
Red flag: the lab name is the same as the vendor, or no lab name or address is visible.
The HPLC purity result is the most prominent number on a peptide COA. It represents the percentage of the total sample that is the target peptide.
Also look at the chromatogramif it’s included. A single dominant peak with small baseline impurity peaks indicates high quality. Multiple major peaks is a serious quality issue.
The MS result should confirm that the compound matches the theoretical molecular weight of the claimed peptide. Look for:
Red flag: no mass-spec section at all, or MS data that doesn’t include observed m/z values. A COA without MS cannot confirm the compound’s identity.
NPC represents the true active peptide mass as a percentage of total sample weight. A typical research peptide might have an NPC of 75–85 %, meaning a 10 mg vial contains only 7.5–8.5 mg of actual peptide — the rest is TFA, moisture, and counter-ions.
Without NPC data, dosing from weight alone is inaccurate. This is why NPC is included in all Injectable Safety panels at Gold Standard Analytics.
The most important trust signal on any COA is a verifiable accession numberthat links to the lab’s own public database.
Every COA from Gold Standard Analytics includes a unique accession number you can check at goldstandardanalytics.com/coa-lookup. If the number returns a match, the COA is genuine. If it doesn’t exist in our database, the document was not issued by us.
Red flag: no accession number or verification system. Without this, you have no way to confirm the COA was not fabricated.