This thesis sets out to explore consumers’ health behaviour in an era of increased consumer autonomy with the emergence of a new category o f drugs; those that have ‘switched’ from prescription (Rx) control to over-the-counter (OTC) availability. The switching of drugs presents an opportunity for consumer researchers to explore preventive health behaviour and the move to more self-medication practices by consumers. Nicotine replacement therapy (NRT), to help those who wish to stop smoking, has been one of the most high profile switches in recent years. Smoking is a major health issue worldwide but research remains dominated by the medical community. NRT as an OTC requires researchers to adopt a consumer orientation yet research has been lacking on OTCs generally and consumer behaviour in particular. This study examines the role that NRT plays in the preventive health behaviour of consumers quitting smoking through in-depth phenomenological interviews. As a paradigm and methodology Existential-phenomenology places the consumer at the centre-stage of the inquiry, recognising the importance of experience as a method to gain understanding of a chosen phenomenon. This paradigm, in line with many others in the fie ld of interpretative research, recognises that the consumer of the nineteen nineties is qualitatively different from our earlier understanding. The results are presented as themes that emerged from the interpretation of the phenomenological interviews and aim to capture the meanings that consumers hold in relation to NRT, as an OTC. The themes are framed from two case studies; detailed presentations of the consumption stories of two respondents. The themes are reflective of the consumer’s meaning categories and uncover many salient aspects, not previously indicated in the literature. Finally, the conclusions and implications for switch drugs and health care are presented with some recommendations for further research on this emerging area.