Who Truly Discovered Insulin? Frederick Banting vs. Nicolae Paulescu — A Story of Science, Ego, and the Lives Saved Between Them

PART I — Before Insulin, Diabetes Meant Slow Death

For most of human history, diabetes was a quiet executioner. Physicians recognized it by its signature symptoms — wasting, thirst without end, sweet-smelling urine — and they knew its outcome: death. Children diagnosed with what we now call Type I diabetes rarely lived long. Doctors could starve the patient to buy a little time, but starvation was a thin victory. Families hoped for miracles; science had none to give.

Even in the early 20th century — the era of electricity, railways, and radios — diabetes remained untreatable. The disease was known, observed, feared, but not stopped. Some physicians suspected the pancreas held the key, since removing it from animals induced fatal diabetic symptoms. But suspicion is not a cure, and countless laboratories chased answers through experiments that stalled, failed, or vanished into academic silence.

It is here, in this bleak, medical landscape, that two men appear. They lived far apart, under different governments, spoke different languages, and never met. Yet their research would eventually converge into something that reshaped the fate of millions.

Their names were Nicolae Paulescu and Frederick Banting.

One would die nearly forgotten. One would win a Nobel Prize.And history — depending on who tells it — has not settled the debt fully.

PART II — Nicolae Paulescu: The First Spark

Nicolae Constantin Paulescu, born in Bucharest in 1869, grew up in a world where science was blossoming but still chained to assumptions and guesswork. He studied medicine in Paris, immersed himself in physiology, and returned to Romania to research metabolism and the pancreas. His brilliance was undeniable, though his temper and convictions sometimes made him difficult to work alongside. But brilliance rarely grows neatly.

Around 1910, Paulescu began experiments that would inch the world closer to insulin. His method was direct: he removed the pancreas from dogs, causing severe diabetic symptoms — wasting, sugar-laden urine, metabolic collapse — and then injected extracts made from healthy pancreatic tissue. When the dogs improved, their blood sugar dropped, and their symptoms eased, he knew he was holding something extraordinary. He called the substance pancreina.

Here was the hypothetical hormone made real — a compound created inside the pancreas that regulated sugar in the body. Humanity had spent centuries searching for it. Paulescu had it inside a syringe.

Yet the timing could not have been worse.

Europe collapsed under the weight of World War I, supply lines broke, universities shuttered, and laboratories struggled for survival. Paulescu’s research was interrupted, publications delayed, peers scattered or dead. Still, he resumed his work after the war ended, refined his extracts, and published his results in the Archives Internationales de Physiologie in 1921 in French — a widely respected journal, but not one that circulated far beyond continental Europe.

Paulescu had, without exaggeration, produced experimental evidence of a blood-sugar-lowering pancreatic hormone before anyone else had documented it with such clarity.

But there was a catch — a fatal one.

His extracts worked, yes. But they were crude, unstable, and caused severe side effects. They could not be safely administered to humans. The spark was lit — but it had not yet become a torch.

PART III — Half a World Away, Another Mind Begins to Turn

Across the Atlantic, in Toronto, a young orthopedic surgeon named Frederick Banting struggled through sleepless nights. He wasn’t a famous researcher, not even particularly celebrated in his own hospital. Diabetes was not his field. Perhaps that is why he succeeded — he approached it not as an established problem, but as a solvable one.

In October 1920, Banting scribbled a line in his notebook — a sentence that would change medical history:

“Ligate the pancreatic ducts of dogs… and isolate the internal secretion of the pancreas for treatment of diabetes.”

It was vague, almost crude, but it held a method. Destroy the portion of the pancreas that produced digestive enzymes, leaving only the cell clusters suspected to create the mysterious “anti-diabetic” substance — the hormone Paulescu and others had glimpsed but never refined. Then extract that.

Banting carried this idea to John J.R. Macleod, a professor of physiology at the University of Toronto. Macleod was skeptical — perhaps rightfully so. Countless scientists had tried and failed. But something in Banting’s urgency persuaded him. He offered a lab room, a handful of dogs, and a student assistant named Charles Best. The clock began.

PART IV — Toronto 1921: From Crude Extract to Living Miracle

The early experiments were messy, brutal, desperate. Dogs died. Extracts degraded. Blood sugar levels refused to fall. Banting and Best, exhausted and underfunded, pushed forward with near-religious stubbornness. And then — at last — a dog lived.

The pancreatic extract lowered glucose. Not as dramatically as hoped, but enough to prove possibility. Enough to keep going.

Through months of refinement and failures, they improved the extract. But it still wasn’t pure enough. They needed help — and a biochemist named James Collip stepped in. Collip, quietly meticulous, purified the extract until it was stable, potent, and safe.

On January 23, 1922, history shifted.

A fourteen-year-old boy named Leonard Thompson, pale and fading, received the world’s first injection of a purified pancreatic hormone — what we now call insulin. Within days, his condition improved so drastically it stunned the medical community.

A miracle had occurred — but not by magic. By science, stubbornness, and timing.

PART V — The Nobel Prize and the Shadow Behind It

Recognition followed quickly — faster than Paulescu ever saw in his lifetime. In 1923, the Nobel Committee awarded the Prize in Physiology or Medicine to Frederick Banting and John Macleod. Banting, furious that Best was overlooked, immediately shared half of his prize money with him. Macleod, equally conscientious, shared his half with Collip.

Human insulin therapy spread across the world. Children destined for death lived. Families who once watched sons and daughters fade into skeletal ghosts now watched them recover, gain strength, return to school, grow old. Insulin became a triumph not of genius alone, but of collaboration and refinement.

But there was something unfinished — a question left buzzing in the corners of medical history: Had Nicolae Paulescu been erased?

Romanian scientists argued passionately — Paulescu’s work preceded Banting’s, his articles existed, his results were measurable, his concept was true. Was he not the first to identify the insulin hormone? Did the world crown the wrong man as discoverer? The controversy grew into a historical wound — one that still aches today.

PART VI — What Does “Discovery” Really Mean?

To award credit, we must define discovery — and that is harder than it sounds.

If discovering insulin means identifying the pancreatic hormone that regulates blood sugar, Paulescu stands tall as a pioneer, perhaps even the earliest successful demonstrator. His pancreina lowered glucose levels in diabetic dogs, he documented his method, and he published before the Toronto experiments became famous.

If discovering insulin means creating a therapy that saves human lives safely, Banting and the Toronto team undeniably achieved what Paulescu did not. Their purified extract, tested clinically, replicated reliably, and scaled for mass production, turned diabetes from fatal to manageable. Without them, no matter how brilliant Paulescu was, millions would have continued to die.

Scientists often say: Paulescu discovered the idea. Banting delivered the cure. But history rarely gives out two crowns.

PART VII — Why the Debate Still Matters

The insulin controversy is not just a scientific footnote. It is a living argument about how we honor discovery, how nationalism shapes memory, how language barriers and wartime disruptions bury brilliance. It raises difficult questions:

Do we reward the first idea or the finished solution?Is a discovery incomplete if it cannot yet save a life?How many scientists died unknown while others stood on their shoulders?

In Romania, Paulescu is revered as the true discoverer — a visionary overshadowed by Western recognition and Nobel politics. In Canada, Banting is a hero, a doctor who snatched children from the jaws of death and gave them decades more to live.

Both are right.Both incomplete without the other.

Science is not a single eureka moment — it is a chain reaction.

Paulescu lit the first spark. Banting carried the flame to the patient’s bedside.

Without one, the other fails.

PART VIII — A Legacy Shared, Even If History Refuses to Share the Credits

Today, insulin is so common we forget it was once impossible. Every injection administered is a quiet echo of two men separated by borders, languages, and fate.

If Paulescu were born later, perhaps with better laboratory conditions, better funding, a better world, his pancreina might have evolved into usable insulin. Had he lived to see the Toronto work, he might have been recognized as a precursor, not a rival. But history is not generous — it rewards results, not intentions.

And the result — the boy saved in 1922, the millions saved after — rests undeniably with Banting, Best, Collip, and Macleod. Yet the idea, the first proof that pancreatic extract could control diabetes, belongs to the man in Bucharest whose work was swallowed by war, distance, and time.

So who discovered insulin?

The truest answer is not a name, but a chain.Not a victor, but a lineage. Paulescu proved the hormone existed. Banting proved it could heal. Their stories do not cancel each other — they complete one another.

Epilogue — Credit, Justice, and the Weight of a Drop of Insulin

Some controversies fade. This one will not, because it touches something deeper than labels and prizes — it touches fairness. It reminds us that science is human, not just technical. That brilliance can be buried by war. That history sometimes crowns the one who finished the race, not the one who started it.

But perhaps the triumph is bigger than ego, nationality, or prestige. Because what matters most is not who first held insulin in a vial — but that it exists at all. That children live. That parents receive extra birthdays, extra hand-holds, extra mornings with the ones they love.

Insulin is bigger than Paulescu and bigger than Banting. It is the result of both. The world needed the idea, and it needed the cure. And so, across time, these two men — born strangers — built one miracle together. The grave of one holds the first discovery. The legacy of the other holds the lives saved by it.

And in the middle lives the truth: insulin was not discovered — it was completed.