This book explores the lived experiences of people who interact with needle and syringe program services in Western Sydney, Australia, including participants and industry workers. It locates the research within the wider context of harm reduction and drug policies. It addresses the question "what do needle and syringe programs do?" and seeks to unpack the agency of human and non-human factors to consider the 'more than human' effects of these programmes. Alongside a critical materialist perspective used to interpret the empirical findings, the book demonstrates that needle and syringe programs create new possibilities for engaging with the world by changing the material conditions of illicit drug consumption. It draws on the conceptual contributions of post-humanist thinking from assemblage theory, actor-network theory, and cognate scholarship. Consideration is given to transferable findings and insights for international contexts. The book speaks to scholars andpostgraduate students in the areas such as sociology, criminology, social work, critical public health, cultural studies, and related fields.