This thesis explores the relationship between ecstasy users' experiences in a variety of settings and drug regulation strategies in New Zealand. Fieldwork based, it presents the practices and knowledge utilised by a set of users 'doing ecstasy' in Christchurch. The research aims to both extend the sociological literature on ecstasy consumption and produce an analysis that could contribute to the development of harm reduction strategies in New Zealand. It accomplishes this primarily through interviews in which ten Christchurch users reflect on their experiences with ecstasy. This study is supplemented with participant observation within a number of settings in which ecstasy is consumed and quantitative analysis of forty questionnaires distributed through the social networks of those interviewed. This study contributes to the body of knowledge in the field of sociological drug research and harm reduction policy through its exploration of three themes, production, fluidity and control. I argue that what ecstasy 'does' is neither completely socially constructed nor the direct consequence of the drugs' pharmacology. Instead, I demonstrate that experiences of ecstasy are produced and emerge as an effect of users' employment of specific practices and knowledge. From this perspective, users both 'make' and 'let' the effects of ecstasy occur. Users' practices and knowledge are seen as fluid with respect to time, space, people and place. Finally, users' strategies for controlling and managing their negative experiences of ecstasy are discussed. This thesis demonstrates that users' experiences, practices and knowledges of ecstasy are constantly in flux, and considers the implications of this fluidity for harm reduction policy. Attention is directed towards local practices in specific settings and the relevance of locality and spatiality for drug-related harm. I conclude that harm reduction with respect to ecstasy demands a range of strategies by multiply positioned groups and individual actors. I argue that further detailed qualitative research into users' experiences of ecstasy would be beneficial in the development of harm reduction strategies in New Zealand.