Banting and Best: The Discovery of Insulin
| Category | Research |
|---|---|
| Also known as | insulin discovery, Toronto insulin, Banting Best Macleod Collip |
| Last updated | 2026-04-14 |
| Reading time | 4 min read |
| Tags | historyinsulindiabetesnobel-prizeToronto |
Overview
The isolation of insulin at the University of Toronto between 1921 and 1922 is one of the most celebrated events in medical history. A surgeon, Frederick Banting, working with medical student Charles Best in the laboratory of physiologist J.J.R. Macleod, and later with the biochemist James Collip, extracted a pancreatic substance that dramatically lowered blood glucose in diabetic dogs. Within a year, the substance was purified enough for human use, saving the life of 14-year-old Leonard Thompson in January 1922.
Before this work, type 1 diabetes was a death sentence. Patients wasted away on starvation diets, which only delayed the inevitable. Prior investigators, including Oskar Minkowski, Joseph von Mering, Eugene Opie, and Nicolae Paulescu, had demonstrated a link between the pancreas and diabetes, and Paulescu had in fact isolated an active extract (pancreine) shortly before the Toronto team. However, it was the Toronto group's purification, clinical testing, and rapid licensing to Eli Lilly that brought insulin into widespread medical use.
The Nobel Prize in Physiology or Medicine was awarded jointly to Banting and Macleod in 1923. Banting shared his portion with Best, and Macleod shared his with Collip, reflecting the collaborative nature of the work.
Key People
- Frederick Banting (1891–1941): Canadian surgeon who conceived the idea of ligating the pancreatic duct to isolate the internal secretion.
- Charles Best (1899–1978): Medical student who performed the crucial laboratory work with Banting in the summer of 1921.
- J.J.R. Macleod (1876–1935): Scottish-born physiologist who provided laboratory space, dogs, and scientific guidance.
- James Collip (1892–1965): Biochemist who purified the extract enough for safe human injection.
- Nicolae Paulescu (1869–1931): Romanian physiologist whose 1921 work on pancreine anticipated the Toronto findings.
Timeline
- 1869: Paul Langerhans describes the pancreatic islets that now bear his name.
- 1889: Minkowski and von Mering show that pancreatectomy causes diabetes.
- 1916–1920: Paulescu conducts his pancreatic extract experiments.
- May 1921: Banting and Best begin work in Macleod's Toronto laboratory.
- Late 1921: Collip joins the team and purifies the extract.
- January 11, 1922: Leonard Thompson receives the first insulin injection.
- 1923: Nobel Prize awarded to Banting and Macleod.
- 1923: Eli Lilly begins large-scale insulin manufacture.
Background
Banting's original idea, scrawled in his notebook in October 1920, was to tie off the pancreatic duct in dogs, allowing the digestive (exocrine) tissue to atrophy while leaving the islets of Langerhans intact. This would supposedly allow extraction of the internal secretion without destruction by proteolytic enzymes. Macleod was skeptical but supportive and gave Banting laboratory space and Best as an assistant for the summer while he traveled to Scotland.
The early extracts were crude and caused sterile abscesses in the first human patient. Collip's alcohol-based purification procedure produced a preparation pure enough for clinical use. By late 1922, the Toronto team and Eli Lilly were producing insulin at industrial scale, transforming type 1 diabetes from a fatal disease into a manageable chronic condition.
Modern Relevance
The Banting-Best discovery is still central to modern medicine. Insulin remains essential therapy for type 1 diabetes and for many people with advanced type 2 diabetes. Purification methods evolved from animal pancreas extracts to recombinant human insulin in 1978 and then to insulin analogs such as lispro, aspart, glargine, and detemir. Modern research builds directly on the Toronto tradition — from continuous glucose monitoring to closed-loop "artificial pancreas" systems.
The story also illustrates broader themes in biomedical research: the role of serendipity, the importance of multidisciplinary teams, and the ethical tensions in prize recognition. Banting's decision to share credit with Best and the University of Toronto's decision to license insulin for a symbolic one-dollar fee set enduring precedents for academic pharmaceutical collaboration.
Related Compounds
Related entries
- The First Recombinant Insulin— Humulin, the first recombinant human insulin, was approved in 1982 after being expressed in E. coli by Genentech and developed with Eli Lilly.
- Frederick Banting— Frederick Banting was a Canadian surgeon and Nobel laureate who co-discovered insulin at the University of Toronto in 1921-1922.
- Solving the Structure of Insulin— The amino acid sequence of insulin was solved by Sanger in 1955, and its three-dimensional structure by Dorothy Hodgkin in 1969.