2012 INDUCTEE John J.R. Macleod, MB ChB Diabetes, Evidence-based Medicine & Clinical Trials, Diabetes


September 6, 1876

(Perthshire, Scotland )


March 16, 1935


MD, University of Aberdeen (1898)

Awards & Honours:

1932: Fellow of the Royal Society of Edinburgh

1923: Nobel Prize in Medicine

See All Awards
Picture of J.J.R. Macleod

Directed the research that led to the discovery and clinical use of insulin as an effective therapy for diabetes mellitus

Portrait of JJR Macleod

Inspiring collaborator and determined leader

The uneasy story of the discovery of Insulin begins in 1920, when Dr. Frederick Banting took his research proposal on the pancreases and diabetes to Dr. Macleod’s laboratory. Dr. J.J.R. Macleod worked closely and, often times, in great conflict with Dr. Banting in the planning and execution of the research that led to the discovery. After extensive historical analysis and an investigation by the Nobel Prize Committee, it is clear that Dr. Banting’s research proposal would not have been successfully completed without Dr. Macleod’s contributions. As director of the work, he also played a critical role after the discovery in overseeing insulin production, clinical trials, licensing and ongoing research.

Key Facts

Investigated a wide range of fields, including work on phosphorous content of muscle, air sickness, electric shock, and the chemistry of the tuberculosis bacillus

Played a key role in the introduction of scientific methods of investigation into clinical work

Shared half of his Nobel Prize money with James Collip to acknowledge his contributions to the discovery of insulin

Professional timeline

Impact on lives today

Dr. Macleod's leadership and expertise provided Frederick Banting with the resources and direction he needed to carry out his experiments. By supervising the work in his lab and suggesting improvements, Dr. Macleod made the discovery of insulin possible and its mass production a reality. This medical advance forever changed the lives of those suffering from diabetes and continues to result in millions of lives saved. 

Picture of J.J.R. Macleod


  • Patricia Brubaker PhD accepting award for Dr. Macleod

    J.J.R. Macleod posthumously inducted into the Canadian Medical Hall of Fame

    Represented by Patricia Brubaker, PhD (University of Toronto, Department of Physiology) in Toronto, Ontario.

  • After living in Canada for ten years, Dr. Macleod returned to his native Scotland to become Regis Professor at the University of Aberdeen

  • Frederick Banting and J.R.R. Macleod became the first Canadians to win the Nobel Prize for Physiology or Medicine


  • Drs. Banting, Best, Macleod and Collip announced their discovery of insulin to the world


  • The first human test of insulin was conducted on a 14-year old boy named Leonard Thompson at Toronto General Hospital

    While the first test failed, the Toronto team soon met success.

  • A testament to the respect colleagues had for Dr. Macleod and his work, he was elected President of the American Physiological Society

  • Dr. John J.R. Macleod agreed to take Frederick Banting into his laboratory at the University of Toronto


    Dr. Macleod supplied Dr. Banting with experimental animals as well as a research assistant (Charles H. Best). Macleod worked closely with Banting in the planning and execution of his research.

  • Dr. Macleod came to the University of Toronto as Professor of Physiology

    Upon his arrival he was made director of the Physiological Laboratory and Associate Dean of the Faculty of Medicine.

  • A reflection of his early and longstanding interest in diabetes, Dr. Macleod published Diabetes: Its Pathological Physiology

  • A few years after completing medical school at the University of Aberdeen, Dr. Macleod left the United Kingdom to become Professor of Physiology at Western Reserve University in Cleveland, Ohio

    He remained in this position for 15 years.


He was the stabilizing force in the insulin discovery.