The South American coca plant was established in 19th-century Britain as a medical product before it became a globally restricted drug. Drawing on botanical, economic, pharmaceutical, social, and political perspectives, Kim Embrey analyses how the use and perception of coca changed as it was transferred to Europe. In a process of “cultural dissimilation”, coca was not simply adopted, but embedded into new medical, social, and scientific contexts. The study shows how a plant from the Andes was repositioned in British modernity.