How well do medicinal chemists learn from experience?

To an outsider, the exploration of thousands of molecules to find a small number of potential candidate drugs must appear enormously wasteful, but many medicinal chemists would defend this waste as unavoidable. Here, I provide evidence that suggests that modern medicinal chemists are overproductive in that they synthesise many more compounds than are required to achieve the objectives of the project. The difficulties encountered in finding the data for the analysis presented here prompted the design and implementation of a more rigorous approach to capture the essence of a medicinal chemistry program. The result, medicinal chemistry knowledge sharing (MeCKS), was designed to capture and communicate emerging issues and their solutions to the medicinal chemistry community.