Understanding Peptide Purity and the COA

HPLC (High-Performance Liquid Chromatography) is the industry-standard method for measuring peptide purity. A value of 99% means 99% of the material is the target peptide.

Mass Spectrometry (MS) confirms identity by measuring the exact molecular weight of the peptide.

A complete COA includes: HPLC chromatogram, MS spectrum, sequence, molecular formula, net peptide content, water content, and acetate counter-ion percentage.

Net peptide content matters — a 5 mg vial at 80% net peptide content delivers 4 mg of actual peptide, with the remainder being counter-ions and bound water.