The Discovery of Insulin and the First Children Who Lived Because of It
It was late in the evening, and in a small Toronto laboratory, a child lay still, weak, and emaciated, barely breathing. The air smelled faintly of surgical ether and antiseptic. A syringe stood nearby, filled with a cloudy fluid.
What followed that night would change medicine forever: the injection of insulin, a life-saving elixir no one yet understood fully, into a boy whose body had no means to regulate sugar.
That boy, Leonard Thompson, would survive, and so would the idea that science could reach into the body’s inner workings and bring someone back from the brink.
This is the tale of how insulin went from hypothesis to miracle and how the first children with what we now call type 1 diabetes surged back from near death.
When type 1 diabetes was a death sentence
Imagine you are in 1920. A child begins losing weight, drinking endless water, urinating frequently, slipping into fatigue, and sometimes drifting toward coma. Doctors could offer no real cure.
Some dietary treatments slowed decline slightly, but death was inevitable. Type 1 diabetes (then called “juvenile diabetes”) was synonymous with doom. Medical textbooks told parents: “Sooner or later, coma and death will ensue.”
Symptom by symptom, a body unravels: the pancreas isn’t making enough insulin (or none at all). Glucose builds up in the bloodstream, but cells starve. Kidneys flush water, trying to rid the excess sugar, so a child becomes ravenously thirsty. Ketones accumulate, acidifying the blood. Coma follows.
By 1920, few children lived more than months after diagnosis. The scientific community had ideas (maybe the pancreas held some secret, maybe extracts from animal organs), but nothing worked consistently.
Scientists, guts, and collisions of ideas
In this atmosphere of desperation, Frederick Banting, a relatively obscure surgeon, believed that somewhere in the pancreas was a secret “antidiabetic substance.” He had little funding, no guarantee of success, and many skeptics. But his conviction drew in others.
Charles Best, a young medical student, became Banting’s assistant. J. J. R. Macleod, a physiologist, granted them space and resources at the University of Toronto. Later, James Collip, a biochemist, joined to purify the extract.
Their personalities clashed at times, but they shared something more powerful than ego: they all knew that failure meant death for children.
They worked on dog experiments, removing ducts, trying to extract the “internal secretion.” Many preparations were toxic or ineffective. Sometimes, dogs died from side effects. However, the team gradually improved their methods, including temperature control, purification steps, and dosage testing.
By early 1922, they had an extract that, in dogs whose pancreas had been destroyed, could lower blood sugar and prolong life. It was still crude and dangerous, but it was promising.
First human patients: trembling between despair and hope
The leap from dog to human is terrifying (and rightly so). On January 11, 1922, a 14-year-old boy named Leonard Thompson received the first injection.
The result? A sharp drop in blood sugar. But the preparation was impure, and he developed an abscess at the injection site. The clinical team, disheartened, thought it a failure.
Yet they persevered. Collip improved the purification, removing much of the debris and toxicity. On January 23, a second injection was given, and this time, the boy stabilized. His urine sugar dropped, his ketones receded, his appetite returned, and his strength returned.
That single event was miraculous in context. One could say: the first human to survive type 1 diabetes with insulin. His life ahead was by no means perfect, but death had receded.
Soon after Leonard, other children began receiving insulin. Schools started treating formerly dying kids. Families sobbed in joy when their child lived another month, another year.
Life after insulin: miracle with a margin of caution
We often imagine these early kids stepping into a “normal life.” Some did, though many faced trial and error every day.
Insulin had to be dosed carefully. Too little, and hyperglycemia (high blood sugar) persisted; too much, and dangerous hypoglycemia (low blood sugar) threatened. Every injection was a negotiation with one’s own metabolism.
In the 1920s and 30s, syringes were crude, monitoring tools minimal, and dietary recommendations primitive. Children sometimes died from low sugar, sometimes from infections or complications. But the shift was cosmic: no longer was death immediate. Time opened up.
Over the years, many people lived relatively normal lives—attending school, growing into adulthood, getting married, and working. Their lives weren’t perfect, but they were possible.
Doctors gradually learned to refine:
- Better insulin formulations (long-acting and short-acting)
- Glucose testing methods (urine tests, later blood tests)
- Diet adjustments and timing of meals
- Injection techniques, dosage schedules
Each increment brought small improvements in stability, fewer hospitalizations, and fewer crises.
How insulin changed medicine and society
When insulin became widely available (first sold in 1923 by Eli Lilly and others), a new era in medicine began. Medical research shifted as the success of one endocrine therapy fueled work on hormones, glandular function, and endocrine diseases.
More broadly, the public saw science not as abstract but as life-saving. Charities, fundraising, and advocacy followed. Diabetes associations formed. Pharmaceutical infrastructure grew. Governments funded research and subsidized vital drugs.
In social terms, the discovery raised deep ethical questions: Who owns a life-saving drug? Who has access? How should pricing work when a medicine is essential? Some of those questions echo today, in debates over insulin costs and accessibility.
What can we learn—then and now?
From the story of insulin and the first children, we can draw several lessons that matter for our time:
- Persistence matters more than brilliance: The discovery wasn’t one eureka moment, but many incremental steps, failures, and adjustments. In research as in life, occasional failure is inevitable, and grit carries you forward.
- Science is human: The story has personalities, conflict, and mistakes. That messiness humanizes the process and helps us trust it more (not less).
- Health is relational: A body is not isolated; environment, diet, stress, and support systems matter. Managing insulin is not just a biochemical puzzle, but a lived negotiation.
- Access is justice: A life-saving therapy matters little if people cannot obtain it. We still confront insulin pricing crises and gaps in healthcare equity, especially in poorer nations.
- Wonder keeps us going: Sometimes we forget that injecting a hormone to regulate metabolism is nothing short of miraculous. Remembering the awe opens us to humility, gratitude, and curiosity.
A return to that room
Let’s return to that quiet lab where Leonard lay still. The surgeon’s hands held a syringe. The team watched. A child on the brink. And then—life.
Now imagine a modern child with type 1 diabetes: they use continuous glucose monitors (CGMs), insulin pumps, and smartphone apps that warn of hypoglycemia. People travel, play sports, and pursue careers. The difference is immense, but the core miracle remains the same: insulin.
We owe a debt to those first children and scientists. They walked a dangerous path so others could live longer, fuller lives.
So the next time you hear about a medical breakthrough (say, a new gene therapy, a novel drug, or a regenerative tissue scaffold), pause for a moment. Think of Leonard and of the many children who got one dose of hope when nothing else worked.
Science can be slow, messy, and strange. But when it connects with compassion and perseverance, it can lift a child from death’s grip.
That is not just a story of insulin. It’s a story of what we can do when we refuse to accept that suffering is inevitable.
Read the full story about how insulin was discovered in the brilliant “The Discovery of Insulin” by Michael Bliss.
