Open ten peptide "certificates of analysis" and you'll see ten different lab names, portals and A-to-F grades. Most look official. Very few can be checked by you. This is a plain guide to who's who, sorted into what you can independently verify and what you can't. The standard we hold everything to is a verifiable own-name Janoshik certificate.
A result is only real proof if you can (1) look it up on the lab's own server by its report number, not a page on the vendor's own site; (2) see the compound, purity and the date the sample was received; and (3) match the batch or lot on the certificate to the vial you were actually sent. Anything that fails all three, an anonymous lab, a "verify" button that only checks the vendor's own site, a recycled or undated certificate, or the seller's own "in-house QC", is not independent proof.
The EU lab the serious end of the market uses. HPLC purity plus mass-spec identity, and every test gets a unique code you can check on Janoshik's own server. Fabricated certificates fail against that public database. Universal caveat: like any lab, it only tests the vial submitted to it, so one certificate proves that sample, not every future batch.
Some US labs are at least real, named and track-recorded even where they lack a public code-checker: MZ Biolabs (Tucson, DEA-licensed), Freedom Diagnostics (Franklin TN, real signer, public COA database), and ISO/IEC 17025-accredited labs such as ACS, Vanguard and ILS (accreditation you can check via ANAB). Real accreditation is a genuine external check most in this market lack, though it still doesn't fix the self-submission problem below.
Being here doesn't automatically mean fraud. It means you cannot independently re-check the result, or the "tester" has a conflict of interest, so a certificate from them is not proof the way a verifiable Janoshik one is. Where something is an allegation rather than a checkable fact, we say so.
If the "lab" is the seller or an affiliate, the numbers are self-reported, not independent, with every incentive to drop failed batches. A real certificate is re-checkable on the lab's own server.
One clean result gets re-attached to new inventory as lot numbers change, so the certificate no longer matches the vial. Check the batch and the sample-received date.
Stolen certificates with swapped logos, generic templates with no batch data, and AI-generated chromatograms (tell: peaks too clean, no baseline noise). One documented case had its verification code and QR removed, and the underlying test number belonged to bacteriostatic water from an unrelated supplier.
A QR or button that resolves to the vendor's own site instead of a neutral lab server proves nothing. Real verification lands on the lab's database.
TrustPointe, Krause, MZ Biolabs and Freedom Diagnostics are real, named labs: where we flag them it is about how a result is used (a single self-submitted vial) or a documented accuracy gap, not fraud. Anonymous operations (Chromate, Axonis) are flagged for checkable transparency failures, no named people, address, accreditation or independent verification, not for a specific proven lie. Allegations are labelled as allegations. If we've got something wrong or out of date, tell us and we'll correct it.
To put this into practice: learn how to verify a Janoshik COA in under a minute, check any certificate free with the COA Checker, or see which UK sellers publish one you can verify.