Home › Guides › Purity vs Identity on a COA: Don't Confuse the Two By TorontoHealth Editorial · Updated June 17, 2026
Purity vs Identity on a COA: Don't Confuse the Two
Short answer: A COA reports two separate things people constantly confuse. Identity = is it the right compound. Purity = what percentage of the sample is that compound. A 99% pure sample of the wrong molecule is still useless.
Identity, explained
Identity testing confirms the sample is the molecule named on the label. Without it, a purity number is floating free — pure what, exactly?
Purity, explained
Purity is the share of the sample that's the target compound, with the rest being by-products, fragments, or filler. A higher number is better, but only once identity is confirmed.
The trap of reading one number
Marketing loves a big purity figure because it sounds impressive in isolation. Always pair it with the identity result before you trust it.