In the chilly January of 1922, a frail 14-year-old boy named Leonard Thompson lay dying in a Toronto hospital. His body ravaged by Type 1 diabetes, Leonard weighed only 65 pounds, and his desperate family had tried every starvation diet available under medical care. With death imminent, Leonard’s name would soon be etched into medical history as the first human to receive an injection of insulin—a moment that would change the fate of millions living with diabetes.
In the early 20th century, a diagnosis of Type 1 diabetes was effectively a death sentence. The pancreas, unable to produce insulin, left the body incapable of regulating blood sugar. Children and young adults, in particular, faced a grim future. As described by historian Michael Bliss, “Diabetes was a slow, wasting, and relentless killer. The best physicians could do was prolong life by starving the patient.”
The Search for a Cure
The breakthrough that gave hope to patients like Leonard began with Dr. Frederick Banting, a young Canadian surgeon inspired by a simple but powerful idea: that the pancreas contained a substance capable of controlling blood sugar. In 1921, Banting approached Professor J.J.R. Macleod at the University of Toronto, who, despite skepticism, provided Banting with laboratory space and a research assistant, Charles Best. Together, Banting and Best worked through the summer heat, performing grueling experiments on dogs to isolate the elusive pancreatic extract.
Recalling the urgency of their work, Charles Best later said, “We realized we were racing against time, not just for our research, but for the lives of countless children.”
After months of painstaking trial and error, the team succeeded. The extract, later named insulin, drastically lowered blood sugar in diabetic dogs. The next challenge was to purify it for human use. Biochemist Dr. James Collip joined the effort, applying his expertise to refine the extract.
With Leonard Thompson’s condition rapidly deteriorating, his father consented to the experimental treatment. On January 11, 1922, Leonard was injected with the first batch of insulin. The initial results were disappointing: Leonard suffered an allergic reaction, and his blood sugar did not improve significantly. But hope was not lost.
Collip worked day and night to improve the extract. Twelve days later, Leonard received a second injection—this time, with purified insulin. The transformation was dramatic: his blood glucose dropped, his symptoms abated, and for the first time, Leonard’s family saw hope return to his eyes.
Dr. Frederick Banting recalled, “When we saw Leonard’s blood sugar fall and his condition improve, we knew we had witnessed a miracle. For the first time, diabetes was not a death sentence.”
The World Takes Notice
The news of Leonard Thompson’s recovery spread like wildfire. Soon, insulin was being produced in larger quantities and administered to other diabetic patients in Toronto, and then throughout North America and Europe. Children who had been wasting away began to gain weight, regain strength, and return to school and play.
Professor J.J.R. Macleod, who shared the Nobel Prize in Physiology or Medicine with Banting in 1923, reflected on the achievement: “The discovery of insulin is a testament to the power of collaboration in science. Each member of our team—from Banting’s vision to Best’s perseverance and Collip’s chemistry—played a vital role.”
Beyond the science, the discovery of insulin is a story of hope, resilience, and compassion. Charles Best, moved by the impact of their work, said, “Seeing children brought back to life, gaining strength and hope, was the most profound reward of all.”
The pharmaceutical company Eli Lilly soon partnered with the Toronto team to scale up production, ensuring insulin reached patients worldwide. The discovery also sparked a new era of biomedicine, demonstrating that complex diseases could be tackled with determination and teamwork.
Legacy and Ongoing Impact
Since Leonard Thompson’s first injection 104 years ago, insulin therapy has saved countless lives. While modern diabetes care has advanced with new types of insulin and technology, the essence of Banting’s breakthrough endures. Diabetes is no longer a death sentence; it is a manageable condition, thanks to a handful of determined scientists and one brave boy.
Looking back, Dr. James Collip remarked, “Science gave us the tools; compassion gave us the drive to use them.”
Today, the legacy of Leonard Thompson and the insulin pioneers lives on in every person with diabetes who celebrates another birthday, attends another school play, or dreams of the future—a testament to one of medicine’s greatest triumphs.
References: Bliss, M. (1982).
The Discovery of Insulin.
University of Chicago Press; Banting, F.G., Best, C.H., Collip, J.B., Macleod, J.J.R. (1922).
The Effect of Pancreatic Extracts on Diabetes; Nobel Prize Lectures, 1923.
