Perfect Peptides

Every batch is run through HPLC, which separates the material into its components, then checked by mass spectrometry to confirm the peptide is what it claims to be. The purity figure we publish is the size of the main peak as a percentage of everything the instrument detected.

That number has limits worth knowing. It measures what the method can see — water, salt and solvent sit outside it entirely, which is why they are reported as separate lines on the certificate of analysis rather than buried in one headline figure. A high percentage on its own is not the whole picture, and the CoA is where the rest of it is.