Homogeneity

Homogeneity is the even distribution of an active ingredient throughout a batch, so that every unit or serving contains close to the same amount.

A batch can meet its average potency and still vary considerably from unit to unit if the active was not mixed thoroughly, if it settled during filling, or if it separated in storage. Homogeneity testing samples several units or positions within a batch and compares their results. It matters most for products divided into discrete servings, such as gummies, capsules and measured droppers.

A standard certificate of analysis usually reports a single result from one composite sample, which reflects the average and not the spread. A per-serving figure on a label is meaningful only if the batch is homogeneous, and a reader has no way to tell from a single result whether it is. Some laboratories offer homogeneity or unit-to-unit testing, and companies that perform it can say so. Uneven products explain why one serving can seem different from the next.