A Certificate of Analysis (CoA) is one of the most important documents for researchers working with peptides. It serves as proof that the product has been properly tested for purity, identity, and quality — and knowing how to read one helps ensure your experiments are reproducible and your results trustworthy.
Purity Percentage
The first thing to look for is the peptide’s purity percentage, which indicates the level of contaminants or impurities present. Reputable suppliers provide purity levels of 98% or higher; Aesthetic Labs batches are tested to ≥99%.
Identity Testing
Check for information about identity testing, usually confirmed through methods like mass spectrometry or HPLC. This ensures the peptide’s molecular structure matches its intended design — purity alone means little if the molecule is not what the label claims.
Traceability Details
A proper CoA should also include the testing laboratory, batch number, and date of analysis. These details make each vial traceable to a specific verified batch and support transparency between supplier and researcher.
Third-Party Verification
Always confirm that your supplier uses independent third-party testing rather than relying on in-house claims. At Aesthetic Labs, all peptides are third-party tested and every batch is accompanied by a detailed CoA — current reports are published on our Lab Results page.