Insulin Discovery by Banting and Best Transforms Diabetes Treatment

In July 1921 researchers at the University of Toronto, surgeon Frederick Banting and his assistant Charles Best, isolated a pancreatic hormone that regulates blood sugar, later named insulin. The first human trial was conducted in January 1922 on 14‑year‑old Leonard Thompson, whose blood glucose fell dramatically and whose health recovered.

Banting, Best and professor John Macleod sold the insulin patent to the university for a symbolic $1, and industrial production was licensed to Eli Lilly. Over the decades insulin shifted from animal extracts to genetically engineered human and analogue forms, and delivery evolved from syringes to pens, pumps and continuous glucose monitors. Today the hormone is essential for millions of people with diabetes, though it remains inaccessible in some low‑income regions due to cost and supply challenges.