When sourcing research peptides, the single most important document is the Certificate of Analysis (COA). It is the independent evidence of what a vial actually contains. This guide explains what a COA is, what it should contain, and why third-party testing matters.
What is a Certificate of Analysis?
A COA is a laboratory-issued document that reports the identity and purity of a specific batch of a compound. For research peptides, it confirms that the material in the vial matches what is stated on the label, and to what degree of purity.
What a good COA should show
- Identity — confirmation that the peptide sequence and molecular mass match the expected compound, typically via mass spectrometry (MS).
- Purity — usually a percentage measured by High-Performance Liquid Chromatography (HPLC). Research-grade material is commonly 98–99%+.
- Batch/lot number — so the certificate ties to the exact batch you received.
- Testing date and laboratory — ideally an independent, third-party lab.
Why third-party testing matters
A supplier testing its own product has an obvious conflict of interest. Independent, third-party analysis removes that conflict. This is why reputable research suppliers commission external testing and make the certificate available.
How Peptide Pal handles COAs
At Peptide Pal, every batch is independently third-party tested, and a Certificate of Analysis is available for the material you receive. Purity is verified to 99%+ before a batch is released.
Browse our research peptides, each supplied with third-party analysis.
⚖ All products are supplied for laboratory research use only and are not for human or animal consumption.