Medical ethics has developed methods of differential ethics for a more rigid integration of bioethical reasoning into biomedical research. Due to high levels of risk and uncertainty in phase I trials, established principles of medical ethics need a specific assessment in order to provide for better moral design and moral monitoring of trial procedures, a better translation of medical health status data into individual quality of life criteria, and strong support for trust-based cooperation between physician, research team and patient. Existing bioethical questionnaires and detailed methodological research in differential ethics could be improved further.