In this introduction to the special section ‘Biocircularities: New Formations of Embodied Time’, we introduce the concept of ‘biocircularity’. Drawing on case studies from Senegal, Australia and the United States, we argue that (bio)circularities provides a new tool to understand transformations of embodiment and embodied time in response to rapid technoscientific, social and environmental change. We situate the potential of biocircularity by distinguishing the approach from cycles and ‘looping’. We lay out why we think biocircularity is an important concept now, when we stand on the brink of ecological crisis and reproductive futures appear deeply precarious and uncertain. Biocircularity, we argue, offers new ways of understanding how people live out embodiment and understand biological time. The concept offers new possibilities for theorising and realising scientific practice and public health interventions.