During the last years, authors have paid increasing attention to the study of contextual factors that shape the use of research into a country’s public polices. The concept of Knowledge Regimes, developed by Campbell and Pedersen (and focused on the supply side of policy relevant research), is one of the most significant recent contributions to this literature. This article is a critique of this concept based on the study of three key policy change events during Vázquez administration in Uruguay. In order to explain the political dynamic of knowledge is necessary to understand the supply-side’s main features. But it is also necessary to study demand-side ones. This criticism leads to the construction of a new concept.