Aging population is a global reality that forces public policies based on transdisciplinary research focused on older adults. This raises a series of issues, such as feasability, inequalities, inequities, vulnerability, access to the products generated, and ability to consent, among others. This essay's objective is to reflect on some of the questions that arise from this reality, review basic precepts of research ethics in human beings, and expose the challenges for updating the current guidelines for ethical biomedical research. Aged adults participating in clinical research should be respected, assured of an adequate risk/benefit balance, and selected fairly. The available guidelines generally recognize these basic principles, but they are not entirely guaranteed, as evidenced during the COVID-19 pandemic. This issue poses various ethical challenges and deserves to be considered in the guidelines and regulations for biomedical research with the participation of older adults.