John James Rickard MacLeod

John Macleod grew up in Aberdeen and studied medicine at the city’s Marischal College. In 1923 he was jointly awarded the Nobel Prize for Physiology for the discovery and isolation of insulin, the essential hormone produced by the pancreas that controls blood sugar levels.

Following his studies in Aberdeen, John worked in London and America. In 1918 he moved to the University of Toronto where together with his colleague, Frederick Banting, he made the breakthrough discovery of insulin four years later. Their work was patented, and the proceeds given to the British Medical Research Council for the Encouragement of Research, with neither John nor Frederick taking any payment. In 1926 insulin became available as a manufactured product, transforming the lives of millions of people with diabetes worldwide. In 1928 John returned to Aberdeen as Regius Professor of Physiology at the University, a post he held until his death in 1935.