This article examines how older adults make decisions about their medications through interconnected axes of trust that operate across social networks. Trust is negotiated by older adults enrolled in a deprescribing programme which guides them through the process of reducing medications to mitigate risks associated with polypharmacy. Habermas’ work on the significance of communicative action in negotiating trust within social relationships informs our analysis, specifically in-depth semi-structured interviews with older adults about their medication use and the role of social networks in managing their health. Participants were age 70+ and experiencing polypharmacy. Our analysis discusses the social nature of medication practices and the importance of social networks for older adults’ decision-making. Their perspective reflects the critique of late-modern society put forward by Habermas. Negotiating trust in pharmaceutical decision-making requires navigating tensions across and between system networks (health-care professionals) and life-world networks (family and friends). This study contributes to our knowledge of how distinct forms of trust operate in different social spheres, setting the context for the way health-care decisions are made across social networks. Our analysis reinforces the need for older adults to engage meaningfully in health-care decision-making such that a convergence between system-world and life-world structures is encouraged. This would improve deprescribing programmes’ efficacy as older adults optimise their medication use and improve overall quality of life.