Therapies derived from substances of human origin (SoHOs) such as organs, cells, and tissues provide life-saving or life-changing treatment for millions of people worldwide each year. However, many people lack timely access to SoHO-based therapies because of insufficient supplies of these exceptional health resources and/or broader barriers in access to healthcare. Despite well-established governmental commitments to promote health equity in general and equity of access to SoHOs in particular, information about inequities in access to most SoHO-based therapies is scarce. Furthermore, the issue of equitable allocation of SoHO-based therapies has received little attention from policymakers and ethicists, except in the context of organ allocation for transplantation. Consequently, the extent and nature of potential inequities within and between countries are largely unknown, and few sources of guidance are available to support progress toward equity in global access to SoHO-based therapies. We present here the findings of an international ethics working group convened in preparation for the 2023 Global Summit on Convergence in Transplantation, organized in Santander, Spain. The group sought to assess potential gaps in knowledge about inequities involving SoHO-based therapies, to elucidate systemic factors that may influence access to these therapies, and to consider how policies and frameworks governing access to and allocation of SoHO-based therapies may promote equity when it is necessary to define boundaries in access because of insufficiency of supply. In discussing these challenges, we also outline several recommendations for action by governments and health authorities.