Maria Rentetzi’s paper focused on the early twentieth-century American marketplace, where radium emanations were traded as medical remedies for male debilities, at a time when scientific explanations of sexual impotence in men were shifting from physical to psychological etiologies. Rentetzi showed that an emerging consumer culture enabled both the medical press and the popular press to inundate American men with novel products and treatments for their sexual debilities. In this context, radium—a newly discovered element that was probed mainly in the leading European research institutes—escaped the laboratory walls to become a highly recommended item of commodity. Accredited physicists and physicians facilitated the use of radium emanations and suggested use of the element to restore sexual vigor in men. Beyond the academic and medical context of early-twentieth century science, radioactivity was enlisted to mold masculinities. The discursive practices of advertising radium cures conceptualized the male body as sexually attractive, aesthetically pleasing, and athletic in its form. Advertisers, manufacturers, and medical practitioners not only produced knowledge about the radioactive products they promoted, they also constructed notions of appropriate masculine performance.