In 1999 the promising results of a clinical trial conducted in Uganda to prevent mother-to-child transmission of HIV were publicly announced. The new antiretroviral nevirapine was cheap, innocuous, easy to prescribe, and remarkably effective, reducing by half the rate of infection of babies. This “magic bullet,” which seemed particularly adapted to the African AIDS epidemic became, however, an object of controversy in South Africa, where the health department required further investigation before rendering the drug available in public hospitals. Under the leadership of the Treatment Action Campaign, a battle began in the streets, in medical forums, and in courts. In the end the government was forced to release the drug. Two years later, as various studies had shown secondary effects among babies and worrying resistance among mothers, the World Health Organization recommended that the use of this antiretroviral in monotherapy be avoided whenever possible. This chapter proposes an analysis of the scientific, political, and, ultimately, social life of nevirapine and discusses some of the general issues raised by this case study.