Third-Party Peptide Testing: Why COAs Matter
Certificates of Analysis (COAs) from independent laboratories are the gold standard for verifying peptide quality. Understanding what COAs show and why third-party testing matters protects your research investment.
What is a COA?
A Certificate of Analysis documents the analytical testing results for a specific batch of peptide. A complete COA includes: HPLC chromatogram and purity percentage, mass spectrometry data confirming identity, batch/lot number, date of analysis, laboratory name and accreditation, and appearance/solubility data.
Why Third-Party Testing?
In-house testing by the manufacturer creates a conflict of interest. Third-party testing by independent, accredited laboratories provides unbiased verification. The testing lab has no financial incentive to inflate purity results. All Proxiva Labs COAs are from independent third-party laboratories.
How to Read a COA
Focus on: HPLC purity — should be ?98% for research grade. Mass spec — observed mass should match theoretical mass ±1 Da. Lab identity — verify the testing lab is real and independent. Batch number — should match the vial you received.
Red Flags in COAs
Missing lab name, no chromatogram (just a number), batch number doesn’t match product, testing date significantly older than purchase date, or suspiciously perfect results (exactly 99.99% every time without variation).
Related Articles: HPLC & Mass Spec | Purity Guide | Quality Guide
For research use only. View all Proxiva Labs COAs and shop verified peptides.