Undoubtedly, all sexes, races, ethnicities, and sexual orientations need representation in clinical trials. To increase health in a diverse population, the medical research supporting the development of new and existing medical therapies and diagnostics needs to be investigated in subsets of the target end users.

Within the last decade, the focus on diversity in pre-clinical and clinical research has spread. Journals, governmental agencies, and funding bodies increasingly require that relevant groups are included in the (planned) research before publication or approval. This has led to health benefits for less favoured groups; e.g. in 2018, the Food and Drug Administration (FDA) in the USA required the manufacturers of zolpidem-containing insomnia drugs to reduce the recommended dose for women to half of that for men because new data—that had not been available during drug development 20 years previously—showed a slower drug metabolism in women than in men [1]. Currently, the FDA is working on implementing requirements for a diversity plan for late-stage clinical research [2]. This is good news for the health of under-represented groups, such as the elderly and different ethnic groups [3].