Insulin's origin: 25 words from a failed doctor's sleepless night
Banting was a failed doctor without a single patient in four months; on a sleepless night he fused his lecture notes and a research paper into 25 words, then—bypassing his colleagues—rushed into human experimentation on a dying boy, extracting insulin in an ethical void.
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Insulin's founding logic: 25 words scrawled from insomnia and last-minute lecture prep
Banting was a bankrupt, failed surgeon when tasked with preparing a diabetes lecture for students using only four lines of existing material. Late that night, after reading a research paper while lying in his bathtub, he couldn't sleep. The lecture and the paper collided in his mind. At 2 a.m. he rose and wrote 25 words describing his experiment: ligate dogs' pancreatic ducts, keep them alive until the pancreas atrophied, then isolate and extract the internal secretion. This entire discovery began not with systematic research but with that one sleepless-night insight—Banting later admitted the last five words were incoherent.
— Grant MaltmanA world expert saw him as a proven loser, and gave him the job anyway
Banting brought his 25 words to Macleod, Toronto's leading physiologist after a decade studying diabetes. By academic rank, a failed clinician with only four or five hours of reading and zero patients treated shouldn't have rated a meeting. Macleod said yes because he expected failure—the perfect way to kill this research path with Banting's own failure as evidence, plus he'd get free labor. They despised each other from day one: Banting thought Macleod disbelieved him; Macleod had essentially offered him a brush-off disguised as opportunity.
The first success worked for one day, then the dog died
Banting and graduate student Best caught a dozen stray dogs, removed their pancreases to create diabetic models, extracted pancreatic matter from Dog 391, and injected it into diabetic Dog 410. Hours later, Dog 410's blood sugar genuinely dropped—the first documented instance ever. But the extract was crude, laced with contaminants; the show compared it to scooping a cup from the Hudson River versus filtering through a purifier. It lasted one day before the dog slipped into a coma and died. The breakthrough proved the direction sound; purification remained completely unsolved.
Team conflict ignited the moment the chemist arrived
By late 1921, Macleod judged they needed a true biochemist to break through, so he summoned James Collip, an expert in blood-glucose measurement. Months before, Banting had wanted a biochemist on board; now he feared Collip would seize his credit, treating the collaboration as something only he and Best should own. Come 1922, the team split into two labs—Banting and Best in one, Macleod and Collip in the other—sharing information in public but privately racing to produce the first usable extract.
They hid the first human injection from their own team
Fourteen-year-old Leonard Thompson lay in a hospital blocks away, dying. Banting and Best bypassed Collip (whom Macleod kept in the dark) and convinced Macleod to approach Thompson's father directly, reasoning: ‘He won't live much longer anyway.’ On January 11, 1922, they injected 15 milliliters of crude, contaminated brown extract into Leonard. The medical chart read: ‘no clinical effects observed’; a sterile abscess formed at the injection site. When Collip learned he'd been circumvented, he raged—and threw himself into purification with even fiercer determination.
Alcohol precipitation solved the purification problem by accident
Collip worked several consecutive nights, adjusting the alcohol ratio in the solution, when he discovered a white substance precipitating out—a purer extract he named ‘Collip's hormone’. On January 23, 1922, at 11 a.m., a doctor injected this clear new extract into Leonard again. The effect was instant: blood sugar fell, his eyes opened, he visibly revived. This was insulin's first genuine life-saving success—nearly six months after the first dog experiment.
They sold the patent for $1 to prevent monopoly
Word spread; patients and doctors flooded Toronto. Production was called ‘a hurried cook scrambling’ and ‘bathtub chemistry’. The team partnered with another Canadian lab, securing $5,000 upfront to scale extraction from animal pancreases, then partnered with Eli Lilly to manage exploding demand. They sold the patent to the University of Toronto for a symbolic $1—ensuring no manufacturer could monopolize insulin and so it could reach sick people worldwide at low cost.
The Nobel Prize honored two men, then split itself in two
In 1923 the Nobel Committee awarded only Banting and Macleod, omitting Best and Collip entirely. Banting raged, cabled Best at Harvard, and gave him half his prize; Macleod, caught off guard, deliberated days before splitting his half with Collip. The four split up: Best stayed in Toronto as physiology chair; Macleod went to Scotland; Collip was scrubbed from history until recent decades; Banting became a national hero but died in a 1941 plane crash at age 49—he was carrying gloves Collip had given him at goodbye.
In their own words · checked verbatim
I think the best way to describe it would be a reluctant hero.
Grant Maltman5:13
Diabetes. Ligate pancreatic ducts of a dog. Keep dogs alive to the senile degenerate. Leaving glycoseria. Try to relieve glycoseria.
Frederick Banting10:26
As far as you are concerned, I am the University of Toronto.
J.J.R. McLeod20:54
Okay, we didn't die. I'll try a spoonful.
It was a race against death that they beat.
To you I ascribe half my prize money, Fred.
Frederick Banting34:38
Dear Dr. Banting, I'm a fat boy now and I feel fine. I can even climb a tree.
Figures
| Leonard Thompson's weight | 65 pounds | 1:05 |
| Daily calorie intake during insulin treatment | 450 calories | 1:05 |
| Earliest written diabetes record | 1552 BCE (Ebers papyrus) | 9:24 |
| Banting's substitute teaching rate | $2 per hour | 8:23 |
| First human insulin injection dose | 15 milliliters | 26:07 |
| Patent sale to University of Toronto | $1 | 33:32 |
| Banting's age at death | 49 years old | 36:48 |
| Leonard Thompson's post-treatment lifespan | 13 more years | 36:48 |
| Museum thank-you letters from insulin patients | Nearly 4,000 in 13 languages | 37:50 |
Glossary
- Ebers papyrus
- The oldest surviving medical text, documenting diabetes-like symptoms as early as 1552 BCE
- ligate
- A surgical technique of tying off a duct or blood vessel to block its passage
- islets
- Cell groups in the pancreas responsible for secreting insulin
- intersecretion theory
- Early theory that certain glands release substances into the bloodstream to regulate body function
How to listen
Those curious about medical history, founder-failure-to-triumph arcs, team infighting, or research ethics' gray zones.