The purpose of this article is to historically review biologically based explanations of drug addiction to demonstrate the increased utility of the institutional fads approach in understanding modern medicalization. Our examination reveals that the medicalization of drug addiction has been long in the making, traveling through numerous fads that have attributed drug addiction to various biological matter, including body type or constitution, genetics, psychopathology, and neuroscience or brain imaging. These explanations follow a common trajectory (emerging, surging, and purging) in institutional fad research. Moreover, our analysis indicates that while scientific and technological developments have shaped these approaches’ influence and pathways, so too have political actors and institutional agendas. We begin by discussing how an institutional fads approach enables an improved understanding of the medicalization of drug addiction – a form of deviance – followed by a critique of four main biological explanations: body constitution, genetics, psychopathology, and brain chemistry/imaging. Our review pinpoints the specific narratives advanced and the academic and political interests at work. In doing so, it exposes the limitations of medicalizing one of the nation’s oldest social problems.