How to read a certificate of analysis (COA)

In peptide research, ensuring the integrity and quality of every compound is essential. A certificate of analysis (COA) is an official document that verifies the specifications, purity, identity, and overall quality of a product. Knowing how to read a COA is indispensable for researchers and institutions seeking reproducible, reliable scientific results.

What is a certificate of analysis (COA)?

A COA is a quality-assurance document generated in the laboratory and associated with each peptide batch. It presents the results of a series of standardized tests performed on that batch, confirming it meets the stated specifications. It is generally issued by the manufacturer and validated by third-party laboratories.

Main elements of a COA

Although formats may vary slightly between manufacturers, a complete COA generally includes the following:

• Product name and lot number — unique identifiers for traceability.
• Analysis date — indicates when testing was performed, useful for checking how recent the data is.
• Purity (%) — indicates the peptide’s purity level, generally above 98% for research-grade compounds.
• Identification — confirms the peptide’s identity, typically by mass spectrometry (MS) or HPLC.
• Stability data — information on storage conditions and degradation profile.
• Test methods — describes the analytical methods used (e.g., HPLC, MS, UV spectrometry).

How to verify authenticity

A valid COA should match the product’s lot number and be issued within the six months preceding purchase. It is important to ensure that COAs come from certified laboratories and, where possible, are validated by a third party. This guarantees the credibility of the results and supports reproducibility in research.

Traceability and external verification

Every certificate of analysis (COA) should be fully traceable to the laboratory that performed the testing. Most authentic COAs include a URL or QR code that links to the laboratory’s official website, where the full results can be verified. This transparency ensures the data has not been altered and lets researchers compare the report against independent sources. It is always recommended to verify a COA’s origin before relying on its data.

Why COAs matter

In the unregulated landscape of online peptide distribution, the COA is one of the few concrete documents guaranteeing accountability and scientific integrity. Without it, researchers risk working with lower-quality or misidentified compounds, potentially compromising entire experimental protocols.

Conclusion

Understanding a COA allows researchers to critically evaluate the materials they use. At Vela Peptides, every batch is tested and verified with COAs issued within six months of sale, ensuring transparency and accuracy across the entire catalogue.