Home › Guides › Mass Balance on a COA: Does It All Add Up to 100%? By TorontoHealth Editorial · Updated July 10, 2026
Mass Balance on a COA: Does It All Add Up to 100%?
The core idea: Mass balance asks a simple question — do all the components reported on the COA add up to roughly one hundred percent? A missing chunk is unexplained material.
What mass balance means
Peptide content, water, salts, and related substances should account for nearly the whole sample. A complete COA lets you see the whole picture, not just one flattering number.
Why a gap is a red flag
If the numbers stop well short of one hundred percent, something in the vial isn't accounted for. That unexplained portion is exactly what you'd want explained.
What to ask for
A full report — identity, purity, and the supporting fractions — not a single isolated purity figure.