This Day in Science History - January 11 - First Use of Insulin

On January 11, 1922 insulin was used for the first time on a human patient. Leonard Thompson, a 14-year-old diabetic at Toronto General Hospital received an injection of Dr. Banting and Best's recently purified insulin. They had previously tested their hormone on dogs with positive results. Leonard's diabetes seemed to recede but he developed an allergic reaction. This reaction was later traced to an impurity in their sample and a more purified sample was used two weeks later.

Leonard survived his previous death sentence of diabetes for another 13 years using insulin until he died from pneumonia at age 27. Dr. Best would later earn the 1923 Nobel Prize in Medicine for this achievement and diabetics everywhere were given a chance at a normal life.