This paper aims at contributing to ongoing reflections among historians on the empirical uses of Michel Foucault’s analyses by reflecting on a series of partly interrelated concepts that appeared at different moments in his work. The social reasons for and practicalities of contemporary “biopolitics” are analyzed through a study of the transformations of public health campaigns promoting preventive measures in France in the 20th century. I begin by briefly reassessing the evolution in the way health messages were conceived and various (audio) visual media were used, from the interwar period to the early 1970s. Then, I expound the context of the invention, a few years later, of a new form of public health action: the “large national campaign of prevention,” drawn from commercial advertising and road safety campaigns. Finally, I analyze the radical reframing of its communication strategy undertaken by the French Committee for Health Education, from the late 1970s to the mid-1980s, as well as the growing attention paid to assessing the reception of films and slogans by the “targeted public.” All these questions relating to the transformation of health communication over a few decades are examined through the prism of Foucauldian concepts such as: “security mechanisms” (as opposed to “discipline”), “problematization,” and “subjectivation.”