Charles Best (medical scientist) the pancreatic extract and monitoring glucose levels, MacLeod assigned the biochemist James Collip to the team. In January 1922, while Collip was working on insulin purification, Best and Banting administered prematurely their pancreatic extracts to 14-year-old Leonard Thompson, who suffered a severe allergic reaction. Eventually, Collip succeeded in preparing insulin in a more pure, usable form. Banting, Best and Collip shared the patent for insulin, which they sold to the University of Toronto for one dollar. In 1923, the Nobel Prize Committee honoured Banting and J. J. R. Macleod with the Nobel Prize in Medicine for the discovery of insulin,
Frederick Banting medicine and, in 1919–1920, was Resident Surgeon at The Hospital for Sick Children. Banting was unable to gain a place on the hospital staff and so he decided to move to London, Ontario to set up a medical practice. From July 1920 to May 1921, he continued his general practice, while teaching orthopedics and anthropology part-time at the University of Western Ontario in London because his medical practice had not been particularly successful. From 1921 to 1922 he lectured in pharmacology at the University of Toronto. He received his M.D. degree in 1922, and was also awarded a gold medal.