Before Insulin, Type 1 Diabetes Was a Death Sentence Measured in Months

Leonard Thompson was 14 years old and weighed 65 pounds when he arrived at Toronto General Hospital in January 1922. He had been diabetic for two years. On the starvation diet then used to extend diabetic patients' lives — sometimes fewer than 500 calories per day — he had survived longer than most. His physician thought he had weeks.

On January 11, Thompson received an injection of a pancreatic extract that Frederick Banting and Charles Best had been producing since the summer of 1921. The first dose caused a severe allergic reaction. Two weeks later, with biochemist James Collip's purified version, Thompson received a second injection. His blood sugar dropped from 520 to 120 milligrams per deciliter. He survived. He lived until 1935.

Banting was a 29-year-old orthopedic surgeon with no research training. He had approached John Macleod, a physiology professor at the University of Toronto, who gave him a lab, ten dogs, and a student named Best — then left for a summer vacation in Scotland. The Nobel Committee awarded the 1923 prize to Banting and Macleod, not Best. Banting was furious. He split his prize money with Best. Macleod split his with Collip.

Insulin entered mass production at Eli Lilly within months. The patent was sold to the University of Toronto for one dollar, explicitly so any manufacturer could produce it without royalty obligations. Within a year, patients who had been expected to die were leaving hospitals.