The Battle for Insulin: The Human Drama Behind a Life-Saving Breakthrough

Before 1922, a diagnosis of Type One diabetes was not a diagnosis. It was a death sentence. Mm-hm. A particularly cruel one. Children would waste away to skin and bone. There was no treatment, only a starvation diet that might buy you another year. Maybe. And in that world, the idea of a cure felt like pure fantasy. It reminds me of our penicillin story last week—that forgotten petri dish that changed everything. But this time, the miracle wasn't found by accident. It was dragged into existence by sheer, bloody-minded obsession.

And by four men who, by the end, could barely stand to be in the same room. It all starts with one of them: Frederick Banting. A struggling surgeon in London, Ontario, not a celebrated researcher. And late one night in 1920, he wakes up with an idea. Just twenty-five words he scribbles down that he believes can solve the mystery of diabetes. But an idea is one thing. He needs a lab. He needs resources. He has none. So he goes, hat in hand, to the University of Toronto, to a man named John Macleod. Macleod is Banting’s opposite in every way.

He’s a big deal in metabolism research, established, respected… and deeply skeptical. He listens to this young, excitable surgeon and, you know, he’s not impressed. Not at all. But he agrees, almost dismissively, to give Banting a chance. He offers him a small, derelict lab for the summer, ten dogs for experiments, and a student assistant, Charles Best. And then Macleod does something crucial. He leaves. He goes on holiday to Scotland for the entire summer, leaving these two novices to it. And the work they do that summer is… well, it's brutal.

It's hot, the lab is filthy, and their procedure involves surgically tying off the pancreatic ducts of dogs, waiting for the organ to atrophy, then removing it to make an extract. It’s grim work. They fail again and again. But they are completely driven. And finally, they get a result. They inject their crude pancreatic extract—their "isletin"—into a diabetic dog, and its blood sugar drops. It works. They have it. Or… they think they have it. The problem is, their extract is a thick, brown muck. It’s full of contaminants. When they try to inject it, it causes sterile abscesses.

It’s too impure for a human. They’re so close, but they’ve hit a wall. This is when Macleod returns from his vacation. And he sees that this wild idea he dismissed is not only viable, it might be one of the biggest breakthroughs of the century. And he takes over. Which, you can imagine, did not go over well with Banting. He saw Macleod as trying to steal his glory. Macleod, for his part, saw two amateurs who had stumbled onto something they couldn't finish. And he knew who could. He brings in a fourth man, James Collip. Collip is the missing piece.

He’s a brilliant biochemist. While Banting and Best are fuming, convinced they're being sidelined, Collip locks himself in the lab and, using his expertise, does what they couldn't. He figures out how to purify the extract. And just in time. At Toronto General Hospital, a fourteen-year-old boy named Leonard Thompson is in a diabetic coma. He weighs sixty-five pounds. He’s dying. They have one shot. First, they inject him with Banting and Best’s original, cruder extract. Nothing. His symptoms barely change. The team is devastated.

But then, a few days later, they try again. This time, with Collip’s new, purified insulin. And the effect is… immediate. It’s biblical. His blood sugar plummets to near-normal levels. The boy begins to recover. He sits up. He speaks. He lives. It’s a complete, undeniable miracle. But the moment of triumph is also the moment the war for credit begins. Banting was convinced Macleod had done nothing but lend a lab, and Collip was just a technician. And the Nobel committee seemed to partly agree. In 1923, the prize was awarded to Banting and Macleod.

Banting was FURIOUS. He felt Best, his partner from that first summer, was the one who deserved it. He almost refused the prize. Almost. Instead, he holds a press conference and announces, publicly, that he is giving half of his prize money to Charles Best. It was a spectacular, very public rebuke of the committee. And it worked. The pressure was on. The very next day, Macleod announced he would be sharing his prize money with James Collip. So in the end, they all got a piece. But the partnership was shattered. They patented insulin for one dollar, giving it to the University of Toronto to ensure it was available to everyone.

A moment of pure grace after years of ego and conflict. It proves that discovery isn’t always a lone genius under an apple tree. Sometimes, it’s a brawl in a back alley. And sometimes, out of that mess, you get a miracle that saves millions of lives.