The Perception Filler: A Proposed Conceptual Framework for Ingredient-Interpretation Gaps in Food Supplements.

Food supplement labels distinguish declared active ingredients from excipients, but this distinction does not address whether a declared active ingredient makes a substantive supplemental contribution in the form and quantity used. This Perspectives article proposes the term perception filler as an analytical and descriptive construct for identifying situations in which a declared ingredient may contribute more to the perceived completeness or strength of a formulation than to an interpretable nutritional or botanical contribution. The concept is most relevant to low quantities of raw botanical powders presented among active ingredients, particularly where the declared form provides no basis for estimating active constituent content. Existing regulatory taxonomies governing supplement formulation (active ingredients, excipients, and proprietary blends) do not capture this category: a raw botanical powder declared in the active panel is classified as an active ingredient by default, without any mechanism for evaluating whether its form and declared quantity reflect a substantive supplemental contribution. Using turmeric powder as the primary illustrative example, this article distinguishes perception fillers from excipients, proprietary blends, extract equivalence labelling, and botanical adulteration. It proposes working criteria for identification and argues for clearer disclosure of botanical ingredient form and standardisation percentage where applicable. The concept does not depend on agreed dose thresholds; it rests on the observation that certain declarations are more likely to contribute to a product's formulation narrative than to its stated supplemental function.