Everything you need to know
A peptide COA reports the analytical results for the specific vial that was tested: usually identity, purity and, when ordered, content in mg. It does not prove that every vial in a kit is the same, and a purity percentage alone does not confirm the label fill.
What does a peptide Certificate of Analysis (COA) show?
A peptide COA reports the results of the assays run on the sample the laboratory received: typically identity, HPLC purity and, when ordered, content in mg per vial. Identity answers whether the named peptide is present. Purity is the percentage of total chromatographic peak area that belongs to the target peptide. Content is the number of milligrams in the vial, measured against a characterised reference standard. Injectable panels can add endotoxin by USP <85>, heavy metals, bioburden by USP <61> and sterility by USP <71>. Read the methods and the numbers, not only the headline purity.
What belongs on a useful peptide COA?
Five things. The identity method (retention time, co-injection against a reference standard, or mass). Purity as a percentage of total peak area with the detection wavelength named. Content in mg per vial with the basis of the calculation stated, if the label states a milligram amount. The sample identifiers the lab received, such as the vendor, the lot or batch number and the claimed strength. And a way to verify the document with the laboratory that issued it. If content is missing and the label states milligrams, the certificate has not answered the dose question.
Why can purity look fine while the vial is still wrong?
Purity is a peak area ratio. It does not weigh the vial. Underfill, counterion salt and residual moisture can all leave purity high while the milligrams on the label are wrong. In the Mendias and Awan preprint (doi:10.20944/preprints202604.1748.v1), judged against a compounding-style standard of 90 to 110% of label claim and purity at or above 98.0%, 32.8% of samples met purity but fell outside the amount window, against 3.0% that met the amount while failing purity. That is a third-party analysis of third-party laboratory reports, not a Prodigy study. More on which one fails.
How is a peptide COA different from a supplement COA?
They answer different questions. Supplement COAs usually emphasise heavy metals, microbial limits and the potency of botanicals or vitamins. Peptide buyers usually need identity, chromatographic purity and content in mg per vial first. A general guide to what a COA is is a useful start, but it is not a substitute for reading a peptide-specific report.
Does one COA cover every vial in the kit?
No. A certificate describes the vial that was tested and used up in the analysis. Other vials that share a batch number are not measured by that report. More on what one tested vial covers.
What does a Prodigy Labs peptide certificate include?
It depends on the package. Basic ($195) reports purity with identity by retention time and no content figure. Tier 1 Confirmed + Content ($295) adds identity by co-injection and content in mg per vial. Tier 2 Injectable Safety Panel ($750) adds endotoxin, heavy metals and bioburden. Tier 3 ($1,195) adds the 14-day USP <71> sterility test and mass confirmation. See what each package includes.
Can I verify a certificate?
You should be able to. A certificate that can only be forwarded as a PDF is weaker than one you can check against the issuing laboratory's records. Every certificate Prodigy Labs issues carries a verification link. Verify a Prodigy certificate.