Research use only. Not for human or veterinary consumption. 18+.

How to vet a peptide supplier

Including us. The questions below are the ones that separate a supplier who will tell you what they do not know from one who will not.

Ask what they actually are

Most sellers in this category are resellers. That is not a problem in itself — we are one, and we say so on the front page — but a reseller presenting themselves as a manufacturer is telling you something about how the rest of their claims were arrived at. Ask directly whether they synthesise, and if not, whether they hold stock or ship from their supplier.

Ask about the certificate, not for one

A certificate of analysis is only evidence if the lot number on it matches the lot on the vial. A PDF for a different batch, or one with no lot number, tells you nothing about what you received. Our guide to reading one sets out the four questions worth asking.

Ask what the price is based on

A price behind an account application, a quote form, or a hundred-vial minimum is a price that can move per customer. Published prices can still be wrong, but they cannot be different for you than for the person who asked yesterday. Ours are on every page and on one ladder.

Check the identity claims

Sequence, formula, molar mass and CAS number are all publicly verifiable. Anyone can look up a compound in PubChem and check. A seller who publishes a CAS number that belongs to a different molecule has either not checked or is hoping you will not — and name lookup in public databases genuinely does return the wrong molecule for some peptide names, which is why every record we publish is pinned to a specific database identifier rather than searched by name. Ours are published as open data, with the identifier and the date we read it.

Watch the language

Research chemicals sold with dosing tables, protocols, or the international non-proprietary name of an approved medicine are being sold as something other than research chemicals. What that tells you is not about the product but about who is willing to carry the risk of describing it that way, and how carefully the rest of the operation is likely to be run.

Ask who the importer of record is

On almost every international order in this category, it is you. A seller who implies otherwise, or who promises customs clearance, is making a claim they cannot keep. See shipping for how this works with us.