• Many scientific research manuscripts are intended for other researchers and not the public. However, the public are involved in research as participants, taxpayers, and patients. • We discuss co-creation and how it can be used to enhance medical research. • Co-creation is an iterative, bidirectional collaboration between researchers and laypeople to create knowledge. This process can broaden public engagement in medical research. • Co-creation is related to theories of crowdsourcing, community-based participatory research, citizen science, and participatory action research. • Public online calls for input, crowdsourcing contests, hackathons, and participatory design sessions are all examples of activities to co-create with the public. • Infographics and videos are two tools that can be used to broaden public engagement in medical research.