We argue that there are neither scientific nor social reasons to require gathering ethno-racial data, as defined in the US legal regulations if researchers have no prior hypotheses as to how to connect this type of categorisation of human participants of clinical trials with any mechanisms that could explain alleged interracial health differences and guide treatment choice. Although we agree with the normative perspective embedded in the calls for the fair selection of participants for biomedical research, we demonstrate that current attempts to provide and elucidate the criteria for the fair selection of participants, in particular, taking into account ethno-racial categories, overlook important epistemic and normative challenges to implement the results of such race-sorting requirements. We discuss existing arguments for and against gathering ethno-racial statistics for biomedical research and present a new one that refers to the assumption that prediction is epistemically superior to accommodation. We also underline the importance of closer interaction between research ethics and the methodology of biomedicine in the case of population stratifications for medical research, which requires weighing non-epistemic values with methodological constraints.