Banting and Best Isolate the Hormone Insulin Summary

  • Last updated on November 10, 2022

The work of Frederick G. Banting and Charles Herbert Best in isolating the pancreatic antidiabetic hormone insulin led to lifesaving treatment for countless persons with diabetes.

Summary of Event

Diabetes mellitus Diabetes mellitus has been known since ancient times. The disease in its juvenile form is induced by a deficiency in the “islets of Langerhans,” Islets of Langerhans part of the pancreas, which fail to produce the hormone insulin, a substance that is needed for the utilization of glucose by muscle cells. When deprived of their primary fuel (glucose), the muscle cells produce energy from fat, which results in high blood levels of toxic ketone bodies (acetone). Hormones;insulin Insulin Diabetes mellitus;insulin Medicine;insulin [kw]Banting and Best Isolate the Hormone Insulin (1921-1922) [kw]Best Isolate the Hormone Insulin, Banting and (1921-1922) [kw]Hormone Insulin, Banting and Best Isolate the (1921-1922) [kw]Insulin, Banting and Best Isolate the Hormone (1921-1922) Hormones;insulin Insulin Diabetes mellitus;insulin Medicine;insulin [g]Canada;1921-1922: Banting and Best Isolate the Hormone Insulin[05320] [c]Health and medicine;1921-1922: Banting and Best Isolate the Hormone Insulin[05320] [c]Science and technology;1921-1922: Banting and Best Isolate the Hormone Insulin[05320] Banting, Frederick G. Best, Charles Herbert Collip, James Bertram Macleod, John J. R.

Frederick G. Banting.

(Arthur S. Goss/Library and Archives Canada)

The diabetic has very high levels of glucose in the blood and urine. The patient consumes much fluid, produces much urine, and is always hungry and weak; yet, in spite of eating constantly, the patient loses weight. Once ketone bodies begin to accumulate in the blood, the brain ceases to function and the patient slips into a coma and dies.

The German histologist Paul Langerhans Langerhans, Paul discovered, in 1869, some peculiar cells in the pancreas Pancreas that were later named “islets of Langerhans.” The Swiss anatomist Johann Conrad Brunner, Brunner, Johann Conrad in 1682, showed that if he removed the pancreas, the experimental animals began to drink and urinate continuously. These findings, together with the realization by other scientists that there was a connection between the onset of diabetes and pancreatic lesions, led to a new era: the study of the pancreas as the causative factor of diabetes.

Thus researchers in later years were able to produce diabetes in experimental animals by surgical removal of the pancreas. This led to the demonstration that the pancreatic islets of Langerhans are the source of the insulin necessary for the metabolism of glucose. Nevertheless, from 1910 to 1920, attempts to extract the active ingredient from the islets of Langerhans were unsatisfactory.

This was the situation when a young Canadian surgeon received an inspiration that would become the turning point in the search for the elusive pancreatic hormone. On October 31, 1920, Sir Frederick G. Banting was preparing a lecture on the pancreas for his medical class. After reading an article in the journal Surgery, Gynecology and Obstetrics that reported the finding that the blockage of the pancreatic duct caused the pancreas to shrivel, leaving the islets of Langerhans untouched, Banting had an idea. He began to see how it might be possible to isolate insulin in the pancreas of a dog. He realized that when one tried to extract the insulin from the islets of Langerhans, the pancreatic digestive juice destroyed the hormone before it could be isolated. By letting the pancreas shrivel first, there would be no digestive juice left and the hormone could be isolated intact.

Banting presented his idea to John J. R. Macleod, head of the department of physiology of the University of Toronto, and requested permission to conduct the necessary experimental work in his laboratory. Although Macleod did not believe in the existence of an islet hormone or that Banting would be able to prove otherwise, after long deliberations, he gave permission to Banting to use the facilities and provided him with a graduate student assistant, Charles Herbert Best.

Banting and Best began their experiments on dogs on May 17, 1921. On August 3, the two researchers had the first conclusive result showing that their pancreas extract lowered the blood sugar of dogs who became diabetic after their pancreases had been surgically removed. At first, Macleod was skeptical about Banting’s report on the successful isolation of the antidiabetic hormone, and he made the two researchers repeat their experiments several times. After he was satisfied that the results were valid, he invited James Bertram Collip to join the group.

On December 12, Collip began working on the purification of the extract to make it injectable into humans. On January 23, 1922, it was tested on a fourteen-year-old boy dying of diabetes. The injection of the extract lowered his blood sugar and cleared his urine of ketone bodies and sugar.

The first official paper on the discovery, titled, “Internal Secretion of the Pancreas,” was published in February, 1922, in the Journal of Laboratory and Clinical Medicine by Banting and Best. On October 26, 1923, the Swedish Nobel Committee awarded the Nobel Prize in Physiology or Medicine to Banting and Macleod for the discovery of insulin. Nobel Prize recipients;Frederick G. Banting[Banting] Nobel Prize recipients;John J. R. Macleod[Macleod] The two winners, accompanied by Best and Collip, traveled to Stockholm two years later. On September 15, 1925, at the ceremonial presentation of the award, Banting shared his half of the prize with Best and Macleod followed suit by sharing his prize with Collip.


To appreciate the importance of the discovery of insulin, one need only consider the plight of the millions of diabetics before that discovery was made. The fate of diabetic children was particularly tragic, as, shortly after the onset of the disease, they changed from being healthy and active to weak and drowsy; soon after, they became comatose and died. The parents of such children knew quite well that a diagnosis of diabetes was equivalent to a death sentence.

The discovery of insulin at the University of Toronto was one of the most revolutionary events in the history of medicine. Its impact was so great because of the miraculous effect insulin had on diabetic patients. The most dramatic example of its spectacular power was its ability to conquer the diabetic coma. It has been estimated that at the start of twentieth century, more than fifteen million diabetics were living who, without insulin, would have died at an early age. One of these was the American physician George Richards Minot Minot, George Richards , a juvenile diabetic who had been saved by using insulin. As an adult, he discovered a treatment for pernicious anemia, another disease that in the past had always been lethal. Hormones;insulin Insulin Diabetes mellitus;insulin Medicine;insulin

Further Reading
  • citation-type="booksimple"

    xlink:type="simple">Best, Charles H. Selected Papers of Charles H. Best. Toronto: University of Toronto Press, 1963. Includes a foreword by the Nobel laureate Sir Henry Dale and an introduction by the world-renowned diabetes specialist Eliot P. Joslin. Chapter titled “A Canadian Trail of Medical Research” provides information about Best’s life and his collaboration with Banting in the discovery of insulin. The rest of the book is technical but understandable to a layperson with some science education.
  • citation-type="booksimple"

    xlink:type="simple">Best, Henry B. M. Margaret and Charley: The Personal Story of Dr. Charles Best, the Co-discoverer of Insulin. Toronto: Dundurn Press, 2003. Best’s younger son presents the story of both his father’s research and his parents’ lives, drawing on diaries and other personal documents. Includes photographs.
  • citation-type="booksimple"

    xlink:type="simple">Bliss, Michael. Banting: A Biography. 2d ed. Toronto: University of Toronto Press, 1992. Good biography of the main discoverer of insulin, written in a clear, nontechnical style. Covers some controversial issues and notes some negative elements in Banting’s character. Includes extensive endnotes and index.
  • citation-type="booksimple"

    xlink:type="simple">_______. The Discovery of Insulin. Toronto: McClelland & Stewart, 1982. Interesting, clearly written attempt to give an objective account of the discovery of insulin by the University of Toronto research team. Claims to set the record straight about the roles played by the different persons involved. Includes illustrations, exhaustive bibliography, extensive endnotes, and index.
  • citation-type="booksimple"

    xlink:type="simple">De Kruif, Paul. “Banting Who Found Insulin.” In Men Against Death. 1932. Reprint. New York: Harcourt, Brace, 1960. Tells the story of how Banting and Best discovered insulin. Obligatory reading for anyone interested in the history of the battle waged by medical science for the prolongation of life.
  • citation-type="booksimple"

    xlink:type="simple">Stevenson, Lloyd. Sir Frederick Banting. Toronto: Ryerson Press, 1946. The first complete biography of Banting based on primary sources, written five years after Banting’s death. Emphasizes mainly Banting’s positive attributes, paying little attention to any controversial issues, but is nevertheless a valuable source of information for any student of the history of medicine in general and the history of diabetes in particular. Includes bibliography and index.
  • citation-type="booksimple"

    xlink:type="simple">Wrenshall, G. A., G. Hetenyi, and W. R. Feasby. The Story of Insulin: Forty Years of Success Against Diabetes. London: The Bodley Head, 1962. A good account for the general reader of the historical development of knowledge about diabetes from the earliest times to 1962. Also discusses the role of insulin in the body and the causes and consequences of diabetes. Features a foreword by R. D. Lawrence, a diabetic who, because of insulin, survived to lead a productive life as a renowned clinical researcher. Includes illustrations and index.

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