Every batch we ship is third-party HPLC-verified and COA-backed. Here is what a Certificate of Analysis actually proves, how to read one, and why it is the single most important thing to check before you buy a research peptide.
A Certificate of Analysis — a COA — is the lab document that tells you what is actually inside a vial. For research peptides it is the difference between a supplier who says a compound is 99% pure and a supplier who can show it. A real COA is generated by an analytical laboratory testing a specific manufactured batch, and it reports two things above all else: identity (is this molecule actually the peptide on the label?) and purity (what percentage of the material is that peptide, versus fragments, salts, and impurities?).
When researchers search for peptides with a COA, or a peptide supplier with a COA, this is what they are looking for: not a marketing claim, but a testable, batch-specific document they can read for themselves. At CD Biolab, every product is third-party HPLC-verified and every batch is COA-backed — you can view the COA library here.
A trustworthy peptide COA is built on two analytical methods. Understanding what each one does is most of what you need to read the document confidently.
High-Performance Liquid Chromatography (HPLC) separates everything in the sample by how it moves through a column, then measures how much of each thing is present. On the COA this shows up as a purity percentage — most research-grade peptides report 98%+ or 99%+ — and usually a chromatogram: a graph with one tall, clean peak for the target peptide and, ideally, very little else. A single dominant peak is what you want to see. A cluster of smaller peaks around it means fragments or impurities, and a lower purity number.
Mass spectrometry (MS) answers the identity question. It measures the molecular weight of the compound and compares it to the known, calculated weight of the peptide it is supposed to be. If a COA says a vial contains BPC-157 but the mass spec reports a molecular weight that does not match BPC-157's theoretical mass, the label is wrong — full stop. HPLC tells you it is pure; mass spec tells you it is pure of the thing you actually ordered. You want both.
Open any COA and look for these fields. A complete document has all of them; a thin or fabricated one is usually missing several.
There is a real difference between a manufacturer testing its own product and an independent third-party laboratory testing it. A manufacturer's in-house COA can be accurate — but it grades its own homework. A third-party COA comes from a lab with no stake in the result. When you compare peptide suppliers, a supplier that pays an outside lab to verify every batch is signaling that it expects to pass, and is willing to have someone else confirm it. That is the standard CD Biolab holds every batch to.
BPC-157 is the single most-searched research peptide in the world, which means it is also one of the most commonly mislabeled and under-dosed on the gray market. Searching for BPC-157 with a COA is exactly the right instinct. For a BPC-157 vial, a proper COA should show the BPC-157 sequence, an HPLC purity figure in the 98–99%+ range with a clean single peak, and a mass-spec identity confirming the ~1419 g/mol region that corresponds to the BPC-157 molecule. If any of those three are missing, you are trusting a label, not a lab.
Buying peptides with a COA is not an extra — for research materials it is the baseline. The COA is the only document that proves a vial contains what the label says, at the purity the label claims. Read the purity number, confirm the identity by mass, check for a batch number and a third-party lab, and you have done more due diligence than most buyers ever do. Every product in the CD Biolab catalog ships with that documentation, and the full COA library is public.