Leonard Thompson (diabetic)

Leonard Thompson (1908–1935) is regarded as the very first person to have received injection of insulin as a treatment for diabetes. He received his first injection in Toronto, Ontario, on January 11, 1922, at 14 years of age. The first injection had an apparent impurity which was the likely cause for the allergic reaction he displayed. After a refined process was promptly developed for extracting the insulin, the purified dosage was successfully delivered to young Leonard Thompson twelve days after his first dosage was administered. He then showed signs of improved health and went on to live thirteen more years taking doses of insulin. He died of pneumonia at age 27.

Until insulin was made clinically available, a diagnosis of diabetes was an invariable death sentence, more or less quickly (usually within months, and frequently within weeks or days).