Guide
How to Verify a Peptide Vendor
Most peptide vendors look the same on the surface: clean site, purity claims, a badge or two. The differences show up in what they can prove. This checklist takes about ten minutes per vendor and catches most problems before your money is involved.
1. Find the COAs
A certificate of analysis is a lab report for a specific batch. Look for a COA page linked from the main navigation or the product page. The tiers, from strongest to weakest: a COA published for every lot, a general COA library, COAs sent on request, and a bare purity claim with no documents at all.
If you have to email someone to see a lab report, treat the claim as unproven until the report arrives.
2. Check that the lab is real and named
A COA is only as good as the lab that issued it. The report should name the laboratory. Better labs run their own verification portals where you can paste the report's task number and confirm the document is genuine.
Worked example: every report on Curo's COA page names Janoshik Analytical and carries a verification link to the lab's own portal. Open any lot and follow the link — that is what checkable looks like. A COA that exists only as a PDF on the vendor's own server can be edited by the vendor.
3. Look at the payment methods
Card payment gives you a dispute path if the order never ships. Venmo-only or Zelle-only checkout removes that protection completely — it is the single clearest red flag we track. See the payment red flags guide for the full breakdown.
4. Search the FDA warning letter database
The FDA publishes its warning letters. Search the vendor's name and domain. A warning letter is an allegation of violations, not a finding of guilt, but you should know it exists before you order. Several vendors on this tracker carry one.
5. Check the domain itself
Look at how old the domain is and whether lookalike domains exist. Defunct brands attract clone sites that reuse the name. Peptide Sciences' own shutdown notice warned that any successor site claiming its name is fraudulent — and clones appeared anyway.
6. Check the vendor's record here
We track operating status, documented regulatory events, testing transparency, and payment methods for every vendor on this site, with sources shown. Start at the comparison table and open the vendor's review.