Medicinal chemistry is a fast-evolving interdisciplinary research area which aims to improve human life by developing drugs to combat diseases. Nature Communications interviewed three scientists, Daniele Castagnolo (Associate Professor at University College London), Paramita Sarkar (postdoctoral researcher at University of Würzburg) and Dani Schulz (Director, Discovery Process Chemistry at Merck), about their careers and the past and future in medicinal chemistry research. We asked the researchers what medicinal chemistry means to them, and their opinions on the current relevance of the Rule of Five and new chemical modalities beyond the Rule of Five. We also discuss the differences between academic and industry research in medicinal chemistry and how Open Science can support collaborations for drug development.