Guides
How to read a certificate of analysis (COA)
A line-by-line guide to the one document a peptide shop should be able to hand you — what each field means, what a sound COA looks like, and the gaps that should make you pause.
The journal
Notes from the reading desk
How to read the paperwork, what the lab methods mean, what to ask before you order — and the rules we hold ourselves to.
Lab methods
HPLC vs mass spectrometry: what each test tells you
Two methods appear on almost every peptide certificate. One answers 'how pure?', the other 'is it the right molecule?'. Here is what each can and cannot show.
Guides
Before you order: how to ask a shop for the COA of your batch (and what to check in the imprint)
A short, polite email and five minutes with the imprint tell you more about a peptide shop than any product page. Here is what to send, what to look for, and how our partner shops measure up on paper.
From the editor
Our editorial principles: partners, scores and what “not published” means
Who pays us, why three shops are always listed first, what our scores are built from, and why you will see the words “not published” so often in our tables.