The public and patients can be powerful sensors for shaping and powering healthcare research. They are joining research teams as investigators and collaborators to co-produce evidence for the practical use of interventions in clinical practice. While clinicians and researchers are encouraged by funders and policymakers to involve the public and patients as partners in research, knowledge on what involvement consists of is limited, and the continuum between consultation, collaboration and co-production are not clearly defined. In this article, we explore Patient and Public Involvement (PPI) and introduce greater involvement through research co-production. Co-production describes ways that research partnership can work through public and patient involvement and we outline the similarities of co-production to "The Commons", a strategy utilized by economists to increase effective use of resources. We share examples of how public and patient involvement have used co-production, to demonstrate financial and health benefits. We then outline practical challenges at system, social and cultural levels and consider how others have worked to resolve them.