What ≥99% HPLC Purity Actually Means
The benchmark number, what it measures, and what it doesn't.
By PX1 Research Team · August 4, 2026
What ≥99% HPLC Purity Actually Means
What HPLC measures
Reversed-phase HPLC separates the target peptide from truncation products, deletion sequences and other synthesis-related impurities, reporting the main peak as a percentage of total peak area at a given wavelength.
What it doesn't measure
Purity says nothing about identity, endotoxin load, residual solvents, or water content. Those are separate assays — all four appear on a complete COA.
Why 99% is the benchmark
Above 99%, the impurity profile is dominated by closely related sequences rather than gross synthesis failures, which is the threshold most research protocols assume.
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.