What we measure
Every vendor grade is built from evidence you can verify yourself — never marketing claims. We weigh four things:
- Independent third-party testing (most weight). HPLC purity and potency results from labs the research community trusts — Janoshik Analytical, MZ Biolabs, and Colmaric Analyticals. A result you can look up at the lab beats any claim a vendor makes about itself.
- COA verifiability.A certificate of analysis only counts if it is batch-specific, dated, names an independent lab, and can be verified at that lab. A PDF that can't be checked is worth nothing.
- Track record. Time in operation, consistency across batches, and any documented incidents or fraud.
- Community signal. Patterns in verified buyer reports — used to flag issues, never as a substitute for lab data.
The grades
We use an A–E scale (plus X when there isn't enough testing to grade). A means consistently excellent independent results; E means avoid. Grades move when new lab data comes in — this is a living ranking, not a one-time review.
How we stay independent
- No pay-to-rank. Vendors cannot buy, sponsor, or influence their grade. Affiliate relationships and discount codes affect nothing about the ranking.
- Clear disclosure. When we earn a commission from a vendor link or code, we say so on the page. The grade is calculated the same way whether we earn anything or not.
- Same bar for everyone. Every vendor is measured against the same evidence standard, and we publish the standard right here.
What this site is — and isn't
PeptidePub is an independent price-comparison and research resource. We do not sell, manufacture, or ship anything. All products referenced are sold by third parties as materials for laboratory and research use only — not for human or animal consumption. See our terms and affiliate disclosure.
Questions about how we grade a specific vendor? That transparency is the point — reach out and we'll show our work.