Before the discovery of insulin, a diagnosis of diabetes was essentially a death sentence. Patients were subjected to severe starvation diets, sometimes as low as 450 calories per day, in a desperate attempt to prolong life.
This harsh regimen offered only a few extra months or, at best, a year of survival, often leading to death by starvation rather than the disease itself. – American Diabetes Association
In January 1922, a pivotal moment in medical history occurred.
Leonard Thompson, a 14-year-old boy suffering from type 1 diabetes, became the first human to receive an insulin injection.

The initial injection, derived from a cow’s pancreas, was impure and caused an allergic reaction. Undeterred, researchers refined the formula over the next 12 days.
A second dose was administered, successfully stabilizing Leonard’s condition and marking a monumental shift in diabetes treatment. – NobelPrize.org
This groundbreaking achievement was the result of tireless efforts by Dr. Frederick Banting and Charles Best, who, in 1921, managed to isolate insulin and demonstrated its potential by reversing diabetic symptoms in dogs.
Their work laid the foundation for a therapeutic breakthrough that would transform diabetes from a fatal disease to a manageable condition.
Following Leonard Thompson’s recovery, the University of Toronto took a remarkable step.
They licensed the production of insulin to pharmaceutical companies without seeking royalties, ensuring rapid and widespread distribution.
By 1923, insulin was widely available, saving countless lives worldwide. In recognition of their monumental contribution to medicine, Dr. Banting and Professor John Macleod were awarded the Nobel Prize in Medicine in 1923, one of the fastest recognitions in the history of the prize.
Today, organizations like Beyond Type 1 continue the fight against diabetes, advocating for research, education, and support for those affected by the disease.
Their efforts ensure that the legacy of pioneers like Banting and Best endures, inspiring ongoing advancements in diabetes care and management.
For those interested in supporting the cause, donations can be made to organizations dedicated to diabetes research and patient support, contributing to a future where diabetes can be effectively managed and, eventually, cured.
The journey from the grim days of starvation diets to the life-saving insulin therapies of today underscores the profound impact of medical research and innovation.
As we commemorate these milestones, we also look forward to continued progress in the fight against diabetes.
References cited in this article
First Human Insulin Injection to Treat Diabetes: Details about Leonard Thompson’s initial insulin injection and subsequent treatment refinements. – UMass Chan Medical School
Discovery of Insulin: Information on the discovery of insulin by Sir Frederick G. Banting, Charles H. Best, and J.J.R. Macleod at the University of Toronto in 1921. – Diabetes UK
Leonard Thompson: A 100-Year-Old Recipe for a Miracle: An account of Leonard Thompson’s condition and treatment during the first insulin injection. – JDRF
Frederick Banting, Charles Best, James Collip, and John Macleod: Biographical information on the key figures involved in the discovery and purification of insulin. – Science History Institute
The History of a Wonderful Thing We Call Insulin: An overview of the development and impact of insulin as a treatment for diabetes. – American Diabetes Association
Celebrating Leonard Thompson Day: A reflection on Leonard Thompson’s contribution to diabetes treatment and the significance of his first insulin injection. – Breakthrough T1D
100 Years of Insulin: A commemoration of the 100th anniversary of insulin’s discovery and its significance in medical history. – Penn Today
First Human Receives Insulin Injection to Treat Diabetes: Historical context and significance of the first insulin injection administered to Leonard Thompson. – The HISTORY Channel
The Discovery of Insulin: An Important Milestone in the History of Diabetes Mellitus: A scholarly article detailing the discovery and development of insulin as a treatment for diabetes. – PMC
The ‘Miracle’ Discovery That Reversed the Diabetes Death Sentence: An article from the Nobel Prize organization discussing the impact of insulin’s discovery on diabetes treatment. – NobelPrize.org
Insulin Development and Commercialization: Information on the development, testing, and commercialization of insulin for diabetes treatment. – American Chemical Society
Insulin: Discovery and Controversy: A PubMed article discussing the discovery of insulin and the controversies surrounding it. – PubMed
Leonard Thompson (Diabetic) – Wikipedia: A Wikipedia entry providing an overview of Leonard Thompson’s life and his role in the history of diabetes treatment.- Wikipedia