Open menu
Peptides
Blog
Guides & Tools
New
Search
Switch to light mode
Switch to dark mode
Dosage calculator
Search
Home
Blog
Quality & testing
Blog
Quality & testing
How peptides are tested, what a certificate of analysis proves and how to spot a fake one.
All
Quality & testing
Peptide guides
News & regulation
Quality & testing posts
Quality & testing
HPLC vs mass spec: what each peptide test actually proves
HPLC gives you a purity number. Mass spectrometry tells you what the molecule is. A COA that only has one of them leaves a question open.
Oct 26, 2026