Paper is cheap, analysis is not
An HPLC run with mass-spectrometry identity confirmation costs real money per batch. A PDF that looks like the result of one costs nothing. Whenever those two facts coexist, some sellers will choose the PDF, and in an unregulated market nothing structural stops them.
Fakes fall into two families. The first is pure invention: a template filled with plausible numbers, never near a laboratory. The second is misdirection: a genuine certificate, but for a different batch, a different compound, or a different supplier entirely, passed off as covering the vial in front of you.
The second family is more dangerous precisely because the document itself is real. Which is why the checks below start with the connection between paper and product, not with the paper.
A fake certificate of analysis is rarely undone by the figure it prints. It is undone by everything around the figure, the method line, the column, the run date, the signature, the parts almost nobody reads. Fabricators put their effort where buyers look, and our guide to comparing suppliers turns that same scrutiny into four emails you can send before an order exists.
Four tests a fake usually fails
In rising order of effort. Most fakes fall at the first two.
One document, many orders
A subtler fraud than forgery: a supplier commissions one genuine analysis, then reuses that document for every order of the product line for years. Each certificate is authentic; the claim that it describes your vial is the lie.
The defence is boring and effective: ask for the certificate of the batch you would receive, before paying, and check the batch number when the parcel arrives. Two minutes, twice.
This is also why we tie every certificate to a lot number and send it on request pre-order. Not because our word should carry the weight, but because the whole point of the document is that nobody’s word has to.
Analytical reports written for journals, where nobody is selling anything, are the useful comparison. Method sections in the HPLC peptide purity literature on PubMed are written so that another laboratory could repeat the run, and a value that cannot be repeated is not a measurement. A certificate is that section compressed to a page; if the compression kept only the percentage, it discarded the science. And once the paper has passed, the vial still has to, the storage and shelf-life guide covers what happens to a batch after the day it was measured.
- No batch or lot numberA certificate that floats free of any specific production run certifies nothing.
- Purity given as exactly 99.99%Real chromatography produces untidy numbers. Suspiciously round perfection is a template artefact.
- No laboratory name or addressAnonymous analysis is unverifiable analysis, which defeats the document’s purpose.
- Identity section missing entirelyPurity without identity is a percentage of an unknown. That combination is the fraud’s favourite.
The buying series
This page is one of three. The other two close the remaining gaps.
About fake certificates
Questions this guide gets asked alongside.