although opiates are among the oldest medicines known to human kind, they continue to spark new discoveries in the workings of the brain. And although they remain of interest at the cutting edge of pharmacological research, opiates continue to be mired in intractable social problems. This essay examines the attitudes of physicians toward opiates from about 1890 to 1940. As part of the larger effort to transform medicine into a powerful and self-regulating profession in this period, American physicians sought to increase their control over the distribution of medicines to the sick. In the late nineteenth century, the harm associated with the unregulated American drug market provoked reformers both within and without the profession to action. Opiates were a target of concern because of their prevalence in proprietary medicines, their centrality in therapeutics, their association with symptom-relieving rather than curative medicine, and the risk they posed for addiction. To gauge these concerns, I will examine two kinds of sources. First, charting the actions of the American Medical Association (AMA) shows the role of opiates in the public effort to transform medicine and shake off charges of iatrogenic addiction. Second, within the profession, more private concerns about opiates in medical practice can be traced by surveying textbooks and manuals of materia medica and therapeutics.