Over the past three years, the use of performance-enhancing substances in sports has been in the media spotlight like never before, with publicized positive doping tests in major and minor league professional baseball, professional football, track and field, cycling, weightlifting, tennis, inline skating, boxing, soccer, swimming, softball, Paralympics, and even horse racing. Chemically induced advantages can undermine the traditional principle of a level playing field and the abuse of these substances can lead to health risks. A variety of performance-enhancing substances and methods have evolved, including anabolic steroids, human growth hormone, erythropoietin, and most recently, gene doping. The war against the use of performance-enhancing substances in sports has been waged mostly on two fronts: prohibition of the substances by athletic bodies that have implemented drug testing of players, and federal and state legislation of the substances as dangerous drugs with criminal penalties imposed upon violators. This article focuses on the use of anabolic steroids and steroid precursors by sports competitors and how federal legislators have responded by subjecting possessors of steroid precursor products—which were openly sold in health food stores until January 2005—to arrest and prosecution.