Medicalization theory aims to delineate how and why non-medical issues become demarcated within the realm of medical jurisdiction. The theory postulates that medicalization is marked by diagnostic naming, medical expertise, technological standardization and the de-contextualization of experiential knowledge, and that it is driven by popular media and lay discourse as much as by the communication of health professionals and medical institutions. Although medicalization has been recognized as an inherently rhetorical act, medicalization theory does not attend to the specific communicative means undergirding its orchestration. Drawing from medicalized coverage of the phrase "brain chemistry" ( = 71), we address this theoretical aperture, identifying through rhetorical analysis the most common communicative devices that emerged across 70 years of coverage and three distinct diagnoses (i.e., mental illness, addiction and overweight/obesity). Our findings reveal three central rhetorical means through which medicalization is communicated including mechanical metaphor, pedagogy of contrast, and moral enthymeme. By tracing content across time, the current study explicates the communicative infrastructure that gives rise to medicalization, thereby extending the literature from questions of medicalization occurs and its content is to it is conveyed and imparted.