Abstract
Where regulation is weak, medicine transactions can be characterised by uncertainty over the drug quality and efficacy, with buyers shouldering the greater burden of risk in exchanges that are typically asymmetric. Drawing on in-depth interviews (N = 220) and observations of medicine transactions, plus interviews with regulators (N = 20), we explore how people in Ghana negotiate this uncertainty and come to trust a medicine enough to purchase or ingest it. We identify two mechanisms - attempts to mitigate uncertainty through seeking observable signs of quality and attempts to reduce informational asymmetry - that underpin cognitive assessments of a medicine's trustworthiness. However, these 'cognitive' forms of trust assessment have limited traction where uncertainty is high and trustworthiness remains unknowable, so a third mechanism comes into play: one based on affective relationships within which transactions are socially embedded. Even these, however, cannot eliminate uncertainty, because of the dispersed and under-regulated nature of wider supply chains. In conclusion, we reflect on the need for careful research on actors' practices and decision-making across supply chains to inform more effective policy and regulation.