How to Verify a Peptide Certificate of Analysis Is Real

Reading a certificate of analysis and trusting one are two different problems. A separate guide on this site covers how to read the document — the chromatogram, the area percentage, net peptide content. This one covers the question that comes first: is the certificate in front of you real, and does it belong to the vial you were sent?

That question matters because a forged certificate is easy to produce and hard to spot by eye. A PDF can be edited in minutes. A genuine report from a real laboratory can be lifted from one company’s website and reposted by another. Neither will look wrong. Both will read perfectly if you only assess the numbers on the page.

The four ways a certificate can be false

They are worth separating, because they fail different checks.

Self-issued. The seller tested it themselves, or says they did. There is no independent laboratory named anywhere on the page. Purity is often a suspiciously round figure — 100.00%, or 99.9% on every compound in the catalogue. Nobody’s manufacturing is that consistent.

Borrowed. A genuine report from a real laboratory, but commissioned by someone else. This is the hardest one to catch, because every technical detail on the page is true. What is false is the implied connection between that report and your vial.

Forged. A fabricated document made to look like a known laboratory’s output. Layout is usually close but not exact, and the report number either does not exist or does not resolve.

Stale. A real report for a real batch — from eighteen months ago. Purity was accurate on the day it was measured. It says nothing about the vial that arrived this week.

Check one: does the lot number match the vial in your hand

This is the fastest check and the one most often skipped. The vial should carry a lot or batch number. That same number should appear on the certificate. If the vial has no lot number at all, there is nothing tying it to any certificate, and every other check becomes decorative.

A supplier that publishes one certificate covering an entire product line, rather than one per lot, is telling you something about how closely they track their own inventory.

Check two: verify the report with the laboratory, not with the seller

Independent laboratories in this market — Janoshik Analytical in Prague is the one most commonly used — issue each report with a unique identifier and run a lookup service where that identifier can be checked against their own records. A genuine report resolves. A fabricated one does not.

The important part is how you get to that lookup. Type the laboratory’s domain into the address bar yourself. Do not follow a verification link supplied by the seller, and do not scan a QR code that came with the package. Anyone capable of forging the certificate is capable of standing up a convincing page that confirms it. The verification is only worth something if the seller had no hand in delivering you to it.

Check three: read the client field

This is the check that catches a borrowed certificate, and almost nobody performs it.

An independent report names the party who commissioned the testing — usually a Client field, sometimes a Manufacturer field. If the certificate is genuine but the client is a company you have never heard of, you are looking at somebody else’s test. That may mean your supplier is reselling from that source, which is not automatically bad. It may also mean they pulled a PDF off a wholesaler’s site that has nothing to do with what they shipped you. You cannot tell which from the document alone, and the honest response is to ask.

Check four: purity is not identity

This is the technical point that does the most work, and it is the one most certificates quietly avoid.

HPLC answers one question: what fraction of this sample is the thing that comes off the column at the expected time. It separates by hydrophobicity and measures how much ultraviolet light each fraction absorbs. What it cannot do is tell you what any of those fractions actually are. The detector responds to anything that absorbs UV at that wavelength.

The consequence is worth stating plainly: a very pure sample of the wrong compound passes an HPLC purity test with excellent marks. A 99% figure with no identity confirmation attached means 99% of the material is one substance. It does not establish which substance.

Identity comes from mass spectrometry. The instrument measures mass-to-charge ratio and reconstructs the molecular mass of the intact molecule; a complete report states the observed mass, the theoretical mass for the target peptide, and the error between them. Purity without identity is half a certificate. If a supplier publishes only the HPLC figure, that is worth a question.

Check five: when was it tested

A certificate should carry a test date close to the batch it describes. Peptides are not stable indefinitely, and a purity figure is a measurement taken at a moment, not a permanent property. A report dated well before the manufacturing date is incoherent. A report years old is a historical document.

The signal that arrives before you open the PDF

Whether the certificate is published at all, and when.

“COA available on request” means the document arrives after you have paid. At that point the check has no leverage: your money has moved, the vial is in transit, and if the certificate turns out to be thin your remaining option is a refund argument. A supplier who publishes certificates openly, before purchase, is accepting that anyone can scrutinise them at no cost and with nothing at stake. That is a structural commitment, not a marketing line, and it is visible without reading a single number.

Kinotype publishes the current certificate for every compound on the COA page, before purchase and without an account.

The checklist

• Lot number on the vial appears on the certificate
• An independent laboratory is named, with a report identifier
• That identifier resolves on the laboratory’s own site, reached by typing the domain yourself
• The client field names your supplier, or a source they will explain
• Both purity (HPLC) and identity (mass spectrometry) are reported
• Test date is close to the manufacturing date, and recent
• The certificate was available before you paid, not after

A supplier failing one of these may have a reasonable explanation. A supplier failing several is telling you how much verification they expect you to do, and the answer is none.

What a certificate cannot tell you

Worth ending here, because certificates get treated as a complete answer more often than they deserve.

A certificate describes a sample from a batch at a point in time. It does not describe how the material was handled afterwards, whether the cold chain held in transit, whether the vial you received came from the lot that was tested, or whether anything happened to it between the laboratory bench and your bench. It is strong evidence about manufacturing and no evidence at all about the intervening handling. Storage discipline on your side is not optional because a good certificate arrived with the box.