How to Read a Certificate of Analysis (CoA)

A Certificate of Analysis (CoA) is a document issued by a testing laboratory that summarizes the results of quality control tests performed on a specific batch of product.

At the top of every CoA, you'll find the batch number, test date, and the name of the laboratory that performed the analysis. This information allows you to trace a specific vial back to the exact testing event.

The 'Test Results' table lists each parameter that was measured — typically identity, purity, residual solvents, heavy metals, and microbial contamination — alongside the specification (the acceptable range) and the actual result.

A 'Pass' status means every parameter met its specification. 'Pass with Notes' indicates the batch met its primary specifications but one or more secondary parameters fell slightly outside the typical range — these are flagged for transparency even when they don't affect the core purity claim.

When comparing CoAs across suppliers, look for batch-specific reports (not generic 'representative' reports), an accredited and named testing laboratory, and both purity and identity confirmation — ideally via two independent methods such as HPLC and mass spectrometry.