How to Read a Certificate of Analysis

A Certificate of Analysis (CoA) is a lab document tied to a specific production batch, not to a product line in general. That distinction matters: a CoA for one batch does not guarantee the same result for a different batch of the same compound.

Most CoAs report purity as a percentage, typically measured by HPLC (high-performance liquid chromatography). Look for a specific number, not a vague claim; legitimate CoAs report exact figures like 98.6%, not just 'high purity.'

Identity confirmation is usually done separately, often through mass spectrometry, to confirm the substance is actually the compound it claims to be, not just that whatever is in the vial is pure.

A real CoA will reference a batch or lot number that should match the packaging of the product you received. If it doesn't match, or if a seller can't produce one at all, treat that as a serious red flag rather than a minor detail.