How to spot a fake or copy-pasted certificate of analysis

The same purity figure shows up on every product

Real chromatography has noise. Two genuinely separate HPLC runs on two different batches essentially never return the exact same purity to two decimal places, and a whole catalog of products all reading a suspiciously round "99%" or "99.9%" is a pattern worth noticing, not a coincidence to wave away. A single vendor can legitimately cluster in a tight range; identical figures across unrelated products, batches or even different peptides are the tell.

The batch number doesn't match what's on the vial

This is the single fastest check, and it's the one buyers skip most often. Find the lot or batch number printed on the certificate, then find the one printed on the vial or the shipping label. If they don't match, or the vial has no batch number at all, the certificate isn't proof of anything about the product in your hand — it's proof about a different, unrelated production run.

One sample certificate is standing in for the whole catalog

Some vendors publish a single, real-looking certificate on a homepage or About page and let it imply their entire catalog is tested that thoroughly. That's different from outright fraud, but it's a documentation gap you can check directly: does the specific product page for the item you want to buy have its own certificate, or does the site fall back to "available on request" once you leave the homepage? We flag exactly this pattern in our Core Power Peptides review, where one sample COA appears on the homepage but the tirzepatide product page's own COA tab shows no certificate.

The lab can't be verified

A lab name printed on a PDF is a claim, not a citation. A verifiable lab is one you can search for independently — a real address, an accreditation you can look up in a public database, or a report that links back to the lab's own site rather than a static image hosted by the seller. If the only place the lab's name appears is on the vendor's own certificate, you have no way to confirm the lab exists, let alone that it ran this test.

The scan quality or formatting doesn't hold up

A low-resolution photo of a printout, inconsistent fonts between the header and the results table, or a template that changes from one "certificate" to the next on the same site are all signs the document may have been recreated or edited rather than exported straight from a lab's own system. This isn't conclusive by itself, but it's a reason to weigh the certificate less heavily.

A QR code or "verify" link that doesn't independently verify anything

Some vendors add a QR code or a batch-lookup page as a trust signal. Check where it actually goes. A code that resolves to an independent lab's report or a database entry is a real verification step; one that just reloads the vendor's own homepage or product page is decoration, not proof.

What to do with a red flag

None of these, alone, means a certificate is fake. A missing feature can just mean a smaller vendor with a less polished process. But stacking two or three of these together — no batch match, no verifiable lab, and a purity figure identical to every other product on the site — is a reasonable basis to treat the number as unconfirmed rather than as fact. See how to read a certificate of analysis for the full checklist we score vendors against, and our homepage results for how the three vendors we've checked compare.