This book addresses the history of harm reduction. It evaluates the consequences and constraints, stakes and costs of the policy of needle exchange for the purposes of harm prevention and health research. Vitellone situates the syringe at the centre of empirical research and theoretical analysis, challenging existing accounts of drug injecting which treat the syringe as a dead device that simply facilitates social action between humans. Instead, this book complicates the relationship between human and object - injecting drug user and syringe - to ask what happens if we see the object as an intra-active part of the sociality that constitutes injecting practices. And what kinds of methods are required to generate a social science of the syringe that is able to measure injecting sociality? Social Science of the Syringe develops material methodologies and epistemologies of injecting drug use to enact the syringe as an object of intellectual inquiry. It draws on the methodologies of social anthropology, Actor-Network-Theory, Deleuze's empiricism and new feminist materialism to move towards materially-engaged knowledge production. This interdisciplinary approach improves understandings of the causes and effects of injecting behaviour and the problem of needle sharing, as well as providing a more robust empirical framework to evaluate the motivations and consequences of drug use and drug policy. This book will appeal to researchers and students interested in the sociology of health and illness, STS, Actor-Network Theory, empirical sociology, medical anthropology, social and cultural anthropology, addiction theory and harm reduction.