When the 1923 Nobel Prize for Physiology or Medicine was awarded to Banting and Macleod in the fall of 1923, it was not a surprise to many. This was not a prize that needed a detailed explanation of its significance. Most everyone would have known a friend or relative who had died of diabetes and many might now someone already taking insulin to extend their life. The Time magazine article had predicted Banting would be awarded the prize. Banting, however, was furious at the announcement.
Banting thought that he should have been awarded the prize alone. In his view, Macleod had contributed nothing to the discovery of insulin. Banting had conceived the key experiments, worked without pay and in substandard facilities, and made the discovery of insulin alone while Macleod was vacationing for the summer. Banting told a few close associates that he was considering turning down the prize, but they convinced him to reconsider. Eventually, Banting announced that he would accept the prize and split his share of the money with his assistant, Charles Best.
Macleod’s reaction was diplomatic. He had endured Banting’s rants for several years and while he didn’t enjoy the rantings he did learn to manage them. Macleod announced that the discovery of insulin was a team effort, and he would share his prize money with Collip, the biochemist who first isolated and purified insulin sufficient for human use.