A certificate of analysis (COA) is an independent laboratory’s report on what is actually in a vial. At Pure Performance Labs every product is sent to a third-party lab, and the report is published so researchers can verify identity and purity before ordering.
A good COA covers identity (is it the compound it claims to be?), purity (what percentage is the target compound?), and screening for contaminants. Reading the COA first is the single best habit a researcher can build.