21. Jan Purkinje
Jan Purkinje was a monk turned physician from the Czech Republic who believed that the recommended doses of medications prescribed by physicians were not correct. In order to prove his theory, he began to self-medicate by ingesting drugs himself and then monitoring the side effects.
Purkinje first began by ingesting medicinal plants like foxglove and nightshade, both which are known to stop the heart and blur vision. During his experiments, Purkinje wrote down every detail of what his body experienced. When word got out of his self-experimenting, many in the field reached out to him for help. Purkinje ended up developing atropine, a derivative of nightshade, which is used to dilate the eyes during exams. It’s amazing what you can learn through self-discovery.