This article provides a detailed analysis of the origins and significance of the 1926 clinical trial of Sanocrysin, a gold compound thought at the time to be useful in the treatment of tuberculosis. This experiment is generally considered to be the first clinical trial in the United States that used a formal system of randomization to divide research subjects into treatment and nontreatment groups; it was probably also the first clinical trial in the United States to use placebo shams in a nontreatment control group to overcome the problem of what researchers at the time called “psychic influence.” As such, it was an extremely important moment in the history of clinical trial design. Yet, as I argue, the Sanocrysin experiment also needs to be understood in terms of both the regulatory environment at the time and the commercial interests of Parke, Davis & Company, the pharmaceutical manufacturer that was intent on introducing the drug. Although some historians argue that therapeutic reformers in the twentieth century used experimental science to rein in the commercial forces of the market, this article suggests that, at least in this case, the promotion of rigorous clinical science and the pursuit of corporate profit were deeply intertwined.