If a vendor in this category won't show you a COA, that's the entire review right there.
HPLC (High-Performance Liquid Chromatography) tells you purity — how much of what's in the vial is the compound you expect, versus impurities.
Mass spectrometry tells you identity — confirming the molecule actually is what it's labelled as, not just that it's pure.
You need both HPLC and mass spec to have real confidence in a batch — one without the other tells an incomplete story.
COAs for current batches are available on request while this library is being built out. Email enquiries@peptidegeek.in with the compound and batch number if known, and we'll send it directly.