A percentage, a count per gram and a count per vial are three different measurements. Exosome claims use all three, and they can’t be swapped for one another.
% by weight
How much of an ingredient went into the formula
Says nothing about how many vesicles that ingredient holds
Count per gram or mL
The raw ingredient, by a stated method, on a stated date
Drops once the ingredient is diluted into a finished product
Count per vial or serving
The finished product
Only as strong as its method, lots and timepoint
A percentage usually describes how much of an ingredient, by weight, went into the formula. It tells you nothing about how many vesicles that ingredient holds.
A count per gram or per milliliter describes the raw ingredient, measured by a stated method on a stated date. Once that ingredient is diluted into a finished serum, the count in the bottle is lower, and how it holds up over shelf life is its own question.
A count per vial or per serving describes the finished product. It’s only as strong as the method, the number of lots measured and the timepoint.
Before a number goes on a label, write one sentence that says which of these it is, where it was measured and when. That sentence answers most of what a retailer or distributor will ask.