Reading a certificate of analysis

A certificate of analysis (COA) is the document an independent lab produces when it tests a batch. It is your evidence that what is on the label matches what is in the vial.

The headline figure is purity — the percentage of the sample that is the target compound, usually measured by HPLC. Research-grade material is typically 98%+ pure. The COA will also confirm identity, often by mass spectrometry, verifying the molecular weight matches the intended peptide.

Look for the batch or lot number on the COA and check it matches the vial you received. A COA for a different batch tells you little about the vial in your hand.

LAB 157 sends every production batch for independent third-party analysis before release. If you would like the COA for the batch you received, request it through our support channel once US ordering opens.