In a cramped, overheated laboratory at the University of Toronto in the summer of 1921 C.E., two researchers extracted a substance from a dog’s pancreas and changed the course of medicine forever. What Banting and Best pulled from that tissue would transform one of humanity’s most feared diagnoses — a death sentence rewritten as a manageable condition.
Key findings
- Insulin isolation: Frederick Banting and Charles Best successfully extracted the pancreatic secretion now known as insulin in July 1921 C.E., demonstrating it could dramatically lower blood sugar in diabetic dogs.
- Diabetes mortality: Before the discovery, a diagnosis of Type 1 diabetes meant near-certain death, often within months, as no treatment existed to regulate blood glucose in patients whose pancreases had stopped producing the hormone.
- Clinical breakthrough: By January 1922 C.E., the team — joined by biochemist James Collip, who purified the extract — administered insulin to Leonard Thompson, a 14-year-old diabetic boy, in the first successful human treatment.
The road to the pancreas
The science behind insulin isolation did not emerge from nothing. Decades of work across multiple countries had established that the pancreas played a central role in regulating blood sugar. German researchers Paul Langerhans and Oskar Minkowski had each contributed foundational observations in the late 19th century C.E., identifying the islet cells of the pancreas and linking pancreatic removal to diabetes in dogs.
What had eluded scientists was isolation. The digestive enzymes produced by the pancreas kept destroying the very hormone they were trying to extract. Banting’s insight — tying off the pancreatic ducts in dogs so the digestive tissue would atrophy while leaving the insulin-producing islet cells intact — was the key that unlocked it.
He brought the idea to John Macleod, a leading diabetes researcher at Toronto, who gave Banting lab space, ten dogs, and Best, a young graduate student, as his assistant. The two worked through a sweltering Toronto summer with minimal resources. Their persistence, combined with Best’s skill in blood sugar measurement, produced results that surprised even Macleod.
What the isolation meant in practice
The first human patient, Leonard Thompson, received a crude insulin injection in January 1922 C.E. It caused a serious allergic reaction. Collip spent weeks refining the purification process, and the second injection, given just days later, worked. Thompson’s symptoms cleared. He lived another 13 years — not a long life by modern standards, but one that insulin made possible.
The Toronto team moved quickly. Eli Lilly and Company partnered with the university to scale production, making insulin commercially available in the United States by 1923 C.E. That same year, Banting and Macleod were awarded the Nobel Prize in Physiology or Medicine — one of the fastest Nobel recognitions in history for a medical discovery. Banting, infuriated that Best had been excluded, publicly shared his prize money with his collaborator. Macleod shared his with Collip.
The speed of translation from laboratory to patient was remarkable even by today’s standards. Within two years of that summer experiment, pharmacies across North America were dispensing a drug that had not existed before.
Lasting impact
Insulin did not just save individuals — it reshaped what medicine believed it could do. It demonstrated that a hormone could be isolated, purified, and administered therapeutically, opening a path toward the entire field of endocrinology as a clinical practice.
Over the following century, insulin itself evolved. Beef and pork insulins gave way to synthetic human insulin produced through recombinant DNA technology in the 1980s C.E. — itself a landmark moment in biotechnology. Today, long-acting, rapid-acting, and ultra-rapid formulations give patients a level of control that Banting and Best could not have imagined.
Globally, an estimated 422 million people live with diabetes as of recent World Health Organization data, the vast majority of whom depend on insulin or insulin-adjacent therapies to manage their condition. The discovery made in a Toronto summer heat has extended more human lives than almost any single medical intervention in history.
Researchers are now exploring whether insulin production itself can be democratized further. Scientists at the University of Pennsylvania and other institutions have investigated growing insulin in transgenic plants — including lettuce — as a potential low-cost delivery mechanism for low-income countries where injectable insulin remains difficult to access or afford.
Blindspots and limits
The Nobel committee’s decision to overlook Best and Collip remains a documented grievance in the history of science — a reminder that credit in collaborative discovery is rarely distributed fairly. More broadly, while insulin transformed survival for people with Type 1 diabetes, it has never been a cure. The burden of daily management — monitoring blood glucose, calculating doses, navigating supply chains — remains enormous, and insulin access is still unequal across the world, with high costs pricing out patients in dozens of countries even a century after the discovery. The animals used in the research — hundreds of dogs over the course of the Toronto experiments — bore real costs that shaped the eventual outcome.
Read more
For more on this story, see: Penn Today — 100 years of insulin
For more from Good News for Humankind, see:
- Alzheimer’s risk cut in half by drug in landmark prevention trial
- Global suicide rate has fallen by 40% since 1995
- The Good News for Humankind archive on global health
About this article
- 🤖 This article is AI-generated, based on a framework created by Peter Schulte.
- 🌍 It aims to be inspirational but clear-eyed, accurate, and evidence-based, and grounded in care for the Earth, peace and belonging for all, and human evolution.
- 💬 Leave your notes and suggestions in the comments below — I will do my best to review and implement where appropriate.
- ✉️ One verified piece of good news, one insight from Antihero Project, every weekday morning. Subscribe free.
More Good News
-
Ghana declares its first marine protected area to rescue depleted fish stocks
Ghana’s marine protected area — the country’s first ever — marks a historic turning point for a nation gripped by a quiet fisheries crisis. Established near Cape Three Points in the Western Region, the protected zone restricts or bans fishing activity to allow severely depleted fish populations to recover. Ghana’s coastal stocks have fallen by an estimated 80 percent from historic levels, threatening food security and the livelihoods of millions of small-scale fishers. The declaration also carries regional significance, potentially inspiring neighboring Gulf of Guinea nations to establish coordinated protections of their own.
-
U.S. researchers cut Alzheimer’s risk by half in first-ever prevention trial
Alzheimer’s prevention may have reached a turning point after a landmark trial showed that removing amyloid plaques before symptoms appear can cut the risk of developing the disease by roughly 50%. Researchers at Washington University School of Medicine studied people with rare genetic mutations that make Alzheimer’s nearly inevitable, finding that early, aggressive treatment can genuinely alter the disease’s course. The results, published in The Lancet Neurology, mark the first time any intervention has shown potential to prevent Alzheimer’s from appearing at all, not merely slow its progression. That distinction matters enormously, since amyloid begins accumulating in the brain two…
-
Marie-Louise Eta becomes first female head coach in men’s top-five European leagues
Female head coach Marie-Louise Eta made history on April 11, 2026, when Union Berlin appointed her as interim head coach — becoming the first woman ever to hold a head coaching position in any of men’s top-five European leagues. The Bundesliga club made the move after dismissing Steffen Baumgart, with five matches remaining and real relegation stakes on the line. Eta, 34, had served as assistant coach since 2023 and was already a familiar, trusted presence within the squad. This was no ceremonial gesture — she was handed a survival fight, which is precisely what makes the milestone significant.
