How to read a peptide certificate of analysis

The lot comes first

A certificate describes one production lot, not a product in general. Before reading any number, find the lot identifier and compare it with the lot printed on the vial in hand. If they differ, none of the results apply to that vial. A certificate with no lot number, or one reused across many batches, cannot tell you anything about the material you received.

Who did the testing

Look for the name of the testing laboratory, its location, and whether it is independent of the seller. Useful certificates also show when the sample was received, when results were reported, and an accession or reference number the laboratory can trace. A report produced by the seller itself is a claim, not a verification.

Identity: LC-MS and the ion that proves it

Identity answers the question "is this the molecule on the label". It is established by mass spectrometry, usually LC-MS. A strong certificate states the ion actually observed, for example m/z 710.4 [M+2H]2+, and the molecular weight it corresponds to. For BPC-157 that is consistent with 1419.5 g/mol. "Identity confirmed" with no observed mass is much weaker evidence.

Mass matters most where one trade name covers different molecules. TB-500 is the clearest example: the name is used for a 7-residue fragment of about 888.5 g/mol and for the 43-residue protein thymosin beta-4 of about 4,963 g/mol. Only the mass on the certificate settles which one was tested. See TB-500 vs thymosin beta-4.

Purity: HPLC percentage

Purity is usually reported by HPLC with UV detection as the percentage of the chromatogram area belonging to the main peak, for example 99.51%. It measures how much of the detected peptide material is the target sequence rather than related impurities. It does not measure water, salts or counterions, which is why purity and content are separate figures.

Net peptide content per unit

Net peptide content reports how much peptide is actually present in the vial, for example 10.68 mg in a unit sold as 10 mg nominal. Lyophilized peptides also contain residual water and counterions, so a vial can be high purity and still carry less peptide than its label if content is not reported. A certificate that gives purity but no content leaves the quantity question open.

Testing scope: what was not tested

Good certificates list what was performed and what was not. A typical identity-and-purity panel covers LC-MS identity, HPLC purity, net content, appearance and mass confirmation. It does not cover bacterial endotoxin, sterility, microbial counts, elemental impurities, residual solvents or counterion content unless those are listed. Nothing should be assumed that is not on the certificate for that lot. Where a parameter matters to the planned laboratory work, verify it independently or source material released against that specification.

Red flags

• No lot number, or the same certificate shown for every batch.
• No named laboratory, or a laboratory owned by the seller.
• Identity stated without an observed mass.
• Purity with no net content figure.
• Dates or results that cannot be traced back to the laboratory.
• A certificate only available as an image that cannot be matched to the vial.

How Verum publishes certificates

Every Verum product page embeds the live certificate for the current lot, with the laboratory, dates, methods, results and testing scope reproduced as text. The same record opens when you tap the NFC tag on the vial. See Verify your vial for every product's certificate.