Improving the quality use of medicines (QUM) among seniors, particularly those using multiple medicines, is a national priority. The National Prescribing Service’s Seniors QUM Program was developed in collaboration with consumers to address seniors’ medicines information needs. Seniors are trained as peer educators to convey QUM messages to other seniors in a single group session. However, there is a dearth of research assessing peer education for seniors about medicines, and little understanding of what peer educators do in practice.This research investigated how peer educators empower seniors toward the quality use of their medicines. A participatory action research inquiry was undertaken nationally with organisational leaders and locally with peer educators. The design was a nested case study with multiple sites, where the Seniors Program was the overarching case containing eight disparate local sites. The participatory inquiry engaged peer educators from each local site. Qualitative data were collected through participant observation and interviews. Data were analysed using grounded theory methods and findings were triangulated with other data sources. Peer educators demonstrated five main functions in the program – one primary function within QUM sessions and four support functions outside of sessions. The primary function of facilitating peer learning comprised 10 elements. A model depicts these elements in the context of varying session conditions and consequences. Educators’ lived experience as seniors and lay persons was an overarching contributor to peer learning, used strategically through storytelling to assist other elements. Sharing QUM outside of sessions occurred frequently, but requires development to reach isolated seniors. Peer educators exceeded expectations in getting QUM messages to seniors, applying unique skills to the information exchange within sessions. Their status as lay persons tackling the complex topic of QUM reflected an understanding of the disempowerment seniors may feel when seeking information about medicines. Peer educators’ ability to model an active partner role by applying their lived experience through storytelling in an interactive, mutually sharing session challenged seniors to rethink their medicines management and interactions with health professionals. As the population ages and medicines use increases, understanding and using seniors effectively as educators has great potential. Advisors/Committee Members: Ritchie, Jan, Public Health & Community Medicine, Faculty of Medicine, UNSW, Nathan, Sally, Public Health & Community Medicine, Faculty of Medicine, UNSW, Wutzke, Sonia, Sax Institute, NSW.