While pharmaceutical industry involvement in producing, interpreting, and regulating medical knowledge and practice is widely accepted and believed to promote medical innovation, industry-favouring biases may result in prioritizing corporate profit above public health. Using diabetes as our example, we review successive changes over forty years in screening, diagnosis, and treatment guidelines for type 2 diabetes and prediabetes, which have dramatically expanded the population prescribed diabetes drugs, generating a billion-dollar market. We argue that these guideline recommendations have emerged under pervasive industry (...) influence and persisted, despite weak evidence for their health benefits and indications of serious adverse effects associated with many of the drugs they recommend. We consider pharmaceutical industry conflicts of interest in some of the research and publications supporting these revisions, and in related standard-setting committees and oversight panels. We raise concern over the long-term impact of these multifaceted involvements. Rather than accept industry conflicts of interest as normal, needing only to be monitored and managed, we suggest challenging that normalcy, and ask: what are the real costs of tolerating such industry participation? We urge the development of a broader focus to fully understand and curtail the systemic nature of industry’s influence over medical knowledge and practice. (shrink)