The framework of design for the circular economy is increasingly used in industry to improve product sustainability and decrease costs, and in academia various models have been developed to guide circular design. However, in the medical sector, although it generates a large amount of waste, application of circular design principles is difficult because of the clinical challenges of safety and sterility that reuse of products or materials entail. This paper categorizes and analyses existing instances of circular economy in the medical sector, using a literature review and examination of existing industry examples. This is used to identify challenges and unmet opportunities for circular design in the medical sector. The key factors affecting circular medical design are found to be device criticality in terms of sterilization requirements, device value and the organizational support structure around the device. A design heuristic and suggested strategies for circular design of medical products are proposed based on these findings.