How PeptideScores uses a COA
Certificate evidence informs vendor testing summaries and ratings. It does not certify anything by itself.
Certificates of Analysis are one input among several — reputation, service, shipping, value, and selection are also scored — but they are the input most visitors ask about, and the one this site displays most directly. This guide states what our review of a certificate involves, how the evidence shows up on vendor pages and in scores, and what one report cannot prove. It complements the COA-reading guide, which covers how to verify a certificate yourself.
What our review covers
Reviewing a certificate on this site means inspecting the document itself: 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 document inspection. It 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. How a visitor can check these things independently is covered in the COA-reading guide.
It is also not independent testing. We do not commission laboratory tests of any vendor's products, and no result shown on this site comes from a sample we submitted.
The testing summaries on this site are drawn from 1,521 COA records on file — that figure counts records in our documentation database, including documents on vendors that are not currently ranked, so it is not a count of unique tested products or of ranked vendors.
How the evidence appears on vendor pages
Vendor pages show the certificates on file: the document label, the testing laboratory, and the test types identified in each report, organized under the same testing labels used across this site — the same definitions you'll find under HPLC purity, LC-MS/MS identity, and net peptide content on the testing reference.
Two states matter for a document: it can be publicly listed on the vendor page, or internally approved for publication. Documents pending internal approval are not shown publicly. Approval is an editorial decision made by this site — it is not a statement by the laboratory.
How evidence relates to scores
Certificate evidence feeds the purity & testing category — the heaviest-weighted of the six categories in the composite score. A vendor's testing breadth, the volume of documentation on file, and the results those documents report all affect how that category scores.
The precise weights and rules live on the methodology page. This guide does not restate them; if this guide and the methodology page ever disagree, the methodology page governs.
Limits
A certificate describes one submitted sample. Results apply only to the specific sample, lot, and date identified in the linked laboratory report. A document about one lot is not proof of an entire catalog, and not proof of every unit in a batch.
Purity does not establish suitability for human use. A certificate is an analytical document about a tested sample — it does not validate a manufacturing process, certify a facility, or change a product's research-use-only status.
Updates and corrections
Vendor records, including certificates and testing information, are updated as new documentation comes in and existing documentation changes. If you believe a certificate or a testing summary on this site is wrong, contact us and it will be reviewed against the source document.
Where to go next
Research & Informational Use Only. PeptideScores does not sell, endorse, or facilitate the purchase of any compound for human use. All compounds referenced are intended for laboratory research purposes only. We review vendors; we do not provide dosing guidance, medical advice, or treatment recommendations.