How to Read a Peptide COA (Certificate of Analysis)
Line by line through a real research COA.
By PX1 Research Team · August 4, 2026
How to Read a Peptide COA (Certificate of Analysis)
Header block
Lot number, compound name, CAS where applicable, manufacture date and retest date. If any of these are missing, the document is not lot-specific.
HPLC purity
The percentage plus the chromatogram. Look at the main peak's area percentage and whether impurity peaks are labeled and quantified.
Identity
LC-MS or MALDI-TOF spectrum with the observed mass compared to theoretical. Purity without identity confirms only that something is pure.
Safety panels
Endotoxin (EU/mg), sterility, residual solvents and Karl Fischer moisture. PX1 publishes these at /endotoxin-reports.
How PX1 documents every lot
Every PX1 lot ships with HPLC purity, LC-MS identity, residual solvent, moisture (Karl Fischer), sterility and endotoxin data. Lot documentation is published at /purity-reports, /endotoxin-reports and /coa. Synthesis, purification, lyophilization and vial fill happen in U.S. facilities — see /manufacturing-process.
Research use only. PX1 Research supplies compounds for laboratory and in-vitro research. Nothing here is medical advice, a dosing recommendation, or an offer for human or veterinary use. Figures cited are reported from published laboratory literature.