Before 1921, it was exceptional for people with type 1 diabetes to live more than a year or two.…

Before 1921, it was exceptional for people with type 1 diabetes to live more than a year or two. One of the twentieth century’s greatest medical discoveries, it remains the only effective treatment for people with type 1 diabetes today.

This means that in 2021, we’re celebrating 100 years since the discovery of insulin. It was one of the greatest medical breakthroughs in history, which went on to save millions of lives around the world and triggered a century of diabetes discoveries.

In January 1922, Leonard Thompson, a 14-year-old boy dying from type 1 diabetes, became the first person to receive an injection of insulin. Within 24 hours, Leonard’s dangerously high blood sugar levels dropped, but he developed an abscess at the site of the injection and still had high levels of ketones.

Collip worked day and night on purifying the extract even further, and Leonard was given a second injection on 23 January 1922. This time it was a complete success and Leonard’s blood sugar levels become near-normal, with no obvious side effects. For the first time in history, type 1 diabetes was not a death sentence.