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The First Successful Test of Insulin

For the week of Monday January 22, 2001

On January 23, 1922, the first successful test of insulin on a human patient was performed, becoming the most important Canadian medical discovery of the twentieth century. This breakthrough removed the terror of diabetes for many people.

Dr. Frederick Banting, c.1920-1925

Dr. Frederick Banting, c.1920-1925
© LAC / PA-123481

Diabetes is a disease caused by a lack of insulin in the pancreas. Dr. Frederick Banting knew that when the pancreas was removed, diabetes quickly developed and led to death. Early one morning in October 1920, Banting awoke in his London home with a crystal clear idea for a treatment for diabetes. Believing that secretions in the pancreas were needed to change glucose into cellular energy and thereby avoid diabetes, he decided to test his theory. In May 1921, Banting and his assistant, Mr. Charles Best, began experimenting at the University of Toronto.

Banting came up with the idea of tying off the pancreatic ducts of healthy dogs to make their pancreases shrink. Six weeks later, he removed the shrunken pancreases, ground them up with a saline solution and injected them into diabetic dogs. The scientists noticed that the blood sugar level in the diabetic dogs returned to normal. Banting concluded that the injected pancreatic solution allowed the body to transform the glucose into energy. They named their discovery "Isletin", though it was later renamed "Insulin".

Banting and Best

Banting and Best
© LAC / C-001350

The team of scientists (including Dr. J.J.R. MacLeod and Dr. R.B. Collip) continued their experiments using beef pancreases. Finally, an extract was created, and, on January 11, 1922, 14-year old Leonard Thompson was treated with insulin. No noticeable changes resulted from this test. A few days later, however, a new and purified extraction was created. On January 23, Thompson was again injected, and this time, the test was successful. This discovery became a worldwide life-saving therapy.

Dr. Frederick Banting received international acclaim for his achievement. He and MacLeod were awarded the Nobel Prize for Medicine in 1923, and shared the honour with Best and Collip. In 1972, Banting was designated as a person of national historic significance and his home, considered the "birthplace of insulin", became the Banting House National Historic Site. Provincial and federal commemorative plaques have been erected at the University of Toronto, where the Banting and Best Institute for Medical Research is now located.

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