On January 11, 1922, 14-year-old Leonard Thompson becomes the first person to receive an injection of the hormone insulin for Type-1 diabetes—a disease that for millennia had been considered a death sentence for anyone who developed it. The breakthrough would be one of the most consequential in medical history, saving millions of lives.
Diabetes has been recognized as a distinct medical condition for more than 3,000 years, but its exact cause was a mystery until the 20th century. By the early 1920s, many researchers strongly suspected that diabetes was caused by a malfunction in the digestive system related to the pancreas gland, a small organ that sits near the liver. At that time, the only way to treat the fatal disease was through a diet low in carbohydrates and sugar and high in fat and protein. Instead of dying shortly after diagnosis, this diet allowed diabetics to live—for about a year.
The breakthrough research behind insulin came at the University of Toronto in the summer of 1921, when Canadians Frederick Banting and Charles Best successfully isolated insulin from canine test subjects, produced diabetic symptoms in the animals and then began a program of insulin injections that returned the dogs to normalcy.
In January of the following year, with the support of J.J.R. MacLeod of the University of Toronto, the two scientists began preparations for an insulin treatment of a human subject. With the additional aid of biochemist J.B. Collip, they were able to extract a reasonably pure formula of insulin from the pancreases of cattle from slaughterhouses.
On January 11, 1922, when they began treating 14-year-old Leonard Thompson with insulin injections, the diabetic teenager was critically ill, having wasted to about 65 pounds and slipping in and out of a diabetic coma. After his first insulin injection, he improved dramatically, but suffered an allergic reaction to the insulin. On January 23, after refining the purity of the formula further, the researchers injected Thompson again. His blood sugar levels stabilized and he suffered no ill side effects. He became the face of a new wonder drug.
Exactly one year later, on January 23, 2023, Banting, Best and Collip received U.S. patents on insulin and its manufacturing method. They sold the patents to the University of Toronto for $1 each, with the idea that the medicine should be made widely available to whoever needed it. The University, in turn, immediately gave pharmaceutical companies license to produce insulin, free of royalties. By later that year, insulin had become widely available, and Banting and Macleod were awarded the Nobel Prize in medicine.
