How to verify a lab claim on a peptide COA

A claim of testing by an accredited laboratory can be checked, and the check takes a few minutes using public directories. The check confirms that the laboratory exists, holds an accreditation with the body it names, and covers the relevant kind of test within its published scope.

What it does not do: it does not prove the result on the certificate is right, and it does not prove that the sample described in the report matches the product you would receive. Those limits are covered at the end of this guide.

A named laboratory. A report can name any laboratory. The name appearing on the document tells you only that the document claims that laboratory produced the results. It is not, by itself, evidence about the laboratory.

An accredited laboratory. Accreditation attaches to a laboratory for a defined scope of tests — a list of the kinds of testing the lab is recognized to perform under a defined quality system. A lab accredited for one kind of testing is not accredited for everything it might do, and accreditation can lapse or be suspended.

An accredited method on a specific report. Even an accredited laboratory can report a result outside its accredited scope, or under a method the accreditation does not cover. The claim that matters for a given result is whether that specific kind of test, performed for that report, falls inside the lab's published scope.

One more distinction matters: management-system certification (for example, a company holding an ISO 9001 certificate) is not the same as accreditation to ISO/IEC 17025. The first says the organization runs a quality-management system; the second says a recognized accreditation body has assessed the laboratory's competence to perform specific tests. A certificate that shows only a management-system certification is not showing testing accreditation.

Before checking anything externally, collect what the document itself states:

• the laboratory's legal name and address
• a report or accession number
• the name of the person authorized to release the report (the signatory)
• the date of the report and the date of testing
• the sample or lot identifier the results apply to
• whether an accreditation body mark appears, and whether an accreditation number appears with it

A mark alone is not verification. Logos are easy to copy onto any PDF, and a mark without an accreditation number or a named accreditation body cannot be checked against anything. Treat the mark as a claim to check, not as a finding.

1. Identify the accreditation body named. The certificate should name the body whose mark appears (each accreditation body uses its own mark and numbering format).

2. Look the lab up in that body's own public directory — by the laboratory's legal name or by the accreditation number on the report. Use the directory operated by the accreditation body itself, not a copy or summary supplied by the vendor. The ILAC signatory search is the way to find accreditation bodies and link to their directories. ILAC MRA signatory status means an accreditation body has been peer evaluated by other accreditation bodies.

3. Check that the listing is active. Directories show status. An accreditation that is withdrawn, suspended, or expired is listed with that status or not listed at all.

4. Check that the relevant method is within the published scope. A directory listing usually links or references the scope of tests the accreditation covers. The kind of testing behind the result you are evaluating (for example the HPLC purity or LC-MS/MS identity work described on this site's testing reference) should fall inside that scope. A lab accredited for water chemistry is not thereby accredited for peptide purity.

5. Check that the accredited site is the site that issued the report. Laboratory groups can operate multiple sites, and an accreditation applies to a specific site and its scope. If the report shows an address that differs from the accredited site's address in the directory, the claim does not hold as stated.

Some laboratories provide a way to confirm that a report is genuine — commonly a QR code printed on the report or a verification portal on the lab's website. If the report you are reading offers one:

• check that the code or link resolves on the laboratory's own domain, not a third-party domain
• check that the verification result shows the same report or accession number as the document in front of you

A report that carries no verification route is not automatically fake, but it cannot be authenticated from the document alone. Independent verification of report authenticity is a different step from accreditation checks, and a report can pass one and not the other.

If every step above passes, you have established that the named laboratory exists, is accredited for the relevant scope, and issued a report. That is all it establishes. It does not show:

• that the lot sold to you is the lot described in the report
• that the sample tested was drawn from the vendor's stock rather than supplied for the purpose
• that assays not reported on the certificate are fine — a missing test is an open question, as the missing-test guide explains for each assay
• that other lots match this one

How this site treats certificate evidence — and what its review does and does not involve — is described in how PeptideScores uses a COA.

Our review of a certificate is document inspection: the named laboratory, the tested material, the lot and date, the methods used, the reported results, and whether the document is internally consistent. That is the only thing our current review process does.

It is not laboratory authentication. We do not contact the issuing laboratory to confirm that a document is genuine, and we do not verify accreditation claims at their source. The steps in this guide are things a reader can do independently; they are not steps our review performs.