Read your COA.
Every vial should come with a Certificate of Analysis. Tap any line below to find out what it actually means.
The single most important number on the page. It tells you what percentage of the vial's contents is the target peptide, versus impurities, leftover manufacturing reagents, or fragments that broke down in storage.
Measured by HPLC-UV (high-performance liquid chromatography). The sample is pushed through a column that separates its components, and a detector measures how much of each one comes out. The target peptide shows up as one big peak; impurities show as small ones.
98% or higher is the normal expectation for research peptides; many suppliers target 99%+. A result written as "99.15% ± 0.18%" means the measurement itself has a small margin of error — that's normal and a sign of honest reporting.
No purity figure at all, a suspiciously round "100%", or a percentage with no method named next to it.
A COA describes the material, not what anyone should do with it. BENCH is a calculator and logbook for research use — nothing here is medical advice.
Got your vial checked? Do the math →