Pharmaceutical interventions have brought about many benefits to health, improving the population's well-being and life expectancy. However, these interventions are not without potential harmful side-effects and yet searching for the evidence on adverse effects is challenging. This article summarises a PhD whose main aim was to develop a better understanding of the implications of using different sources and approaches to identifying relevant data on adverse effects. The author is Su Golder, who has recently completed her PhD at the University of York and who has already published several articles on specific aspects of her research, including this journal. This article is the first in the Dissertations into Practice series to report on a PhD study, and it summarises her research in a way which emphasises the implications for practice.