A complete certificate of analysis names the batch, the compound, a purity percentage, the method behind it, the acceptance criteria, the date and who performed the work. Paste any COA below and this says which of those it contains and which it leaves out.
Last updated 2026-10-09 · By the OzPeptides lab team · Runs in your browser
A certificate of analysis is a record of what a laboratory measured on a specific batch, on a specific day, against a written specification. That is a narrow and useful thing. It is not a guarantee, a safety assessment, or evidence about any other batch — including the next one from the same supplier.
The distinction matters because a COA is usually presented as the end of the conversation. It is closer to the start of one. The questions it should answer are: which batch, measured how, against what limit, by whom, and when. A document that cannot answer those five has not told you anything you could check.
This tool looks for those fields and says which are absent. It deliberately does not score documents for quality or judge products, because a document is all it can see.
A batch or lot number ties the document to the glass. Without it the certificate describes an abstraction. The first thing to do with any COA is check its batch against the number printed on the vial — if they differ, nothing else on the page applies to what you are holding.
Compound identity means a sequence, a CAS number or a molecular formula, not just a product name. A purity figure means a percentage; "high purity" and "pharmaceutical grade" are adjectives. The method is what makes the percentage reproducible, usually HPLC with the column and gradient stated.
The date ties the result to a point in time, and acceptance criteria are what turn a result into a pass or a failure. A certificate showing 97.2% with no specification is not telling you whether 97.2% was acceptable. One showing 97.2% against a limit of ≥98.0% is telling you something quite specific.
Net peptide content is the field most often missing and most consequential. Purity describes the composition of what is in the vial; content describes how much is in it. Both reduce what you receive, they multiply together, and only one of them is routinely published.
Heavy metals are the second. "Complies" with no figures and no units is common, and it is an assurance rather than a result — there is no way to tell which limit was applied or how close the batch came to it. Lead, mercury, arsenic and cadmium each want a number and a unit.
Identity confirmation is the third. HPLC answers how much of the detected material was the main peak. Mass spectrometry answers whether that peak is the peptide ordered, by comparing observed mass against theoretical. A certificate with purity and no identity test has answered the easier question and left the harder one open.
Everything above can be present and the document can still be fiction. Fields can be transcribed from a real certificate onto a batch that was never tested. Laboratory names can be invented. Dates can be adjusted. A PDF is a claim in writing and nothing about its layout makes it true.
This is the uncomfortable part of the subject and it is worth being direct about: there is no way to verify a vial from a document. The only verification is an assay of the material you received, by a laboratory you chose. Everything short of that is a question of how much weight the supplier's word carries.
What can be judged is the behaviour around the document. A supplier that publishes results for every batch, including the ones that failed, is making a different kind of claim from one that produces a PDF on request. The first can be checked over time; the second has to be taken as given.
Work through six fields before anything else: the batch number, the compound identity, a purity percentage, the method that produced it, the date of analysis, and the acceptance criteria the result was judged against. A certificate missing any of those cannot be checked against the vial in your hand.
Batch or lot number, compound identity by sequence or formula, purity with the method and the specification, identity confirmation by mass spectrometry, heavy metals with figures and units, net peptide content, water content, the date, and who performed and approved the analysis. Residual solvents, appearance, storage conditions and a retest date are expected on a thorough one.
Yes, and completeness is no defence against it. A document can carry every field and correct-looking numbers while describing a batch that was never tested. A certificate is a claim in writing, not verification. The only thing that verifies a vial is an independent assay of that vial.
It means the supplier is asserting a pass without showing the measurement. For heavy metals in particular, "complies" with no figure and no unit tells you nothing about the limit used or how close the result came to it. A number and a specification is a result; a word is an assurance.
Because they measure different things. Purity is the proportion of the peptide-related material that is the target peptide. Net content is how many milligrams are in the vial. A vial can be 99% pure and underfilled, and the two effects multiply when you work out what you paid per milligram.
No. HPLC says how much of what it detected was the target peak; it does not confirm the peak is the peptide you ordered. That is what mass spectrometry does, by comparing observed mass to theoretical. A certificate with purity but no identity test has answered the easier of the two questions.
It has to, for the document to mean anything. A COA tied to a different batch, or to no batch at all, describes material you do not have. Check the batch number printed on the vial against the certificate before reading anything else on it.
No. The check runs entirely in your browser and the text you paste is never sent anywhere. That is deliberate: it means the tool can be used on a document from any supplier without us seeing it.
For research and laboratory use only. Not for human consumption. Not approved for therapeutic use. Must be 18+ to purchase.