On 11 January 1922, Leonard Thompson, a 14-year-old boy dying from type 1 diabetes, became the first person to receive an injection of insulin. 

Insulin was discovered by Sir Frederick G Banting, Charles H Best and JJR Macleod at the University of Toronto in 1921 and it was later purified by James B Collip.

Within 24 hours, Leonard Thompson’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.  

James 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. 

Click on this link to find out more about this lifesaving research: Who discovered insulin?