Buyer guide
How to read a peptide COA: lot, lab, purity, identity and quantity
By Vitality Chems · Published · updated · vendor-authored explanatory note
Short answer
To read a peptide certificate of analysis, start with the lot number and confirm it matches the vial. Then note the issuing laboratory, the report date, the purity figure and the method used, any identity data such as an observed mass, and the measured quantity in milligrams. A missing test is unreported, not a pass. After you can read the fields, confirm the report with the laboratory itself.
Catalog materials discussed on this page
The fields that matter, in order
Read the report the way a lab would file it, not as marketing. These fields are the ones that let you tell what was actually measured.
- Lot or batch number: must match the vial. A cap color is not a lot number unless the report and the vial use the same description and you know that is all that was issued.
- Issuing laboratory and report or accession number: you need both to confirm the file later.
- Report date: older reports can still be valid for that lot; they do not describe a later lot.
- Purity and method: a percentage without a method (for example HPLC-UV/VIS) is incomplete.
- Identity data, if present: an observed mass or m/z compared with the expected formula weight. Absence means identity was not reported on this certificate.
- Measured quantity: the milligrams found in the tested sample, which can differ from the labeled catalog size.
Worked example: BPC-157 lot BC10051926
On the published Vitality Chems report, the compound is BPC-157, the catalog size is 10 mg, and the lot is BC10051926. The laboratory is Vanguard Laboratory, accession V260521-25 009, reported 2026-06-01. The method is HPLC-UV/VIS. Purity is listed as >99.80% ± 0.18%. The measured quantity is 11.21 mg, which is above the 10 mg catalog size.
This report does not list an LC-MS identity result, endotoxin, sterility or heavy metals. Those items are unreported here. A ten-point checklist for any vendor's certificate is on our peptide COA checklist page.
What a report does not tell you
A certificate describes the tested lot, not the rest of the catalog and not a later production run. It is not a use instruction, a safety evaluation, or a medical document. Research materials from this catalog are for laboratory research only and are not for human or veterinary consumption.
Frequently asked
How do I read a peptide COA?
Match the lot to the vial, then read the laboratory name, report date, purity with its method, any identity data, and the measured quantity. Confirm those values with the issuing lab.
What if quantity is higher or lower than the label?
The measured quantity is what the lab found in the tested sample. Record it. A difference from the labeled size is information about that lot, not a reason to ignore the rest of the report.
Is a purity percentage enough?
No. The report should name the method. Purity also does not identify the compound; identity, when reported, is a separate result.
Where is a longer checklist?
The ten-point peptide COA checklist walks through every field, including chromatograms and lab lookups, and links a free browser checker.
Related on Vitality Chems
- Peptide COA checklist ten checks, with a table and examples.
- How to verify a peptide COA confirm the report with the lab.
- Free COA checker check any report's fields in your browser.
- BPC-157 10 mg catalog page for the worked example.
- Research-use policy what these materials are and are not for.
- Verify a lot look up a published report by the lot on a vial.
- Open COA dataset every published lot report as a table, CSV and JSON.
References
- Vanguard Laboratory verification record for BPC-157 lot BC10051926Worked example of a lab-hosted report.
- 21 CFR 210.3, Definitions (lot, lot number)Regulatory definition of a lot number.
- Vitality Chems peptide COA checklistTen-point field checklist.