How to Read a Peptide Certificate of Analysis (CoA)

A Certificate of Analysis (CoA) is one of the most important documents for researchers working with peptides. It serves as proof that the product you are using has been properly tested for purity, identity, and quality. Understanding how to read a CoA helps ensure that your experiments are reproducible and that your results are trustworthy. The first thing to look for is the peptide’s purity percentage, which indicates the level of contaminants or impurities present. Most reputable suppliers will provide purity levels of 98% or higher. You should also check for information about identity testing, usually confirmed through methods like mass spectrometry or HPLC. This ensures that the peptide’s molecular structure matches its intended design. A proper CoA should also include details about the testing laboratory, batch number, and date of analysis, all of which help with traceability and transparency. When purchasing peptides, always confirm that your supplier uses independent third-party testing to verify results. At Aesthetic Labs, all peptides are third-party tested, and every batch is accompanied by a detailed CoA so researchers can confidently rely on the data provided.