Insulin Timeline

The Insulin Timeline

Canadian scientists Frederick Banting (right) and Charles Best in 1924, three years after they successfully isolated insulin for the first time. (Image: Courtesy of Thomas Fisher Rare Book Library, University of Toronto)

July 27, 1921

Canadian doctors Frederick Banting and Charles Best successfully isolated the hormone insulin, one of the most important breakthroughs in treating diabetes.

In the 20th century, insulin has been one of the most significant medical breakthroughs, alongside antibiotics and cancer therapies. Prior to the discovery of insulin in 1921, people who developed diabetes typically died within a matter of days, months, or at most a few years. However, with the development of insulin therapy, this time frame was extended to decades.

1922 – 1923

Patient JL was a patient of Dr. William McKim Marriott at the St. Louis Children’s Hospital. Prior to the first photograph, he was diagnosed with diabetes for two years and was on a typical starvation diet of the period. He weighed 15 lbs on December 7, 1922.

The second photograph was taken Feb 26, 1923 when he weighed 30 pounds and was on a diet of 55 grams of carbohydrate, 85 grams of protein, and 100 grams of fat. Over the three months he was treated with insulin, his dosage was reduced from 75 units to 15 units, believed to be an indication of an increasing carbohydrate tolerance due to the insulin.

[Note: contrary to many internet postings who mistake this child for Leonard Thompson, this is not Leonard Thompson.]


A production operator and an insulin finishing line.


Seven men are by a truck owned by Capitol Transfer Co. that is holding a 34,000 pound insulin vacuum drier. The truck is parked in front of Eli Lilly Building Number 20 in Indianapolis.

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Leonard Thompson was the first person in the world to receive an insulin injection. He received his first dose in January of 1922 at the age of 14. He lived on insulin for the next 13 years until the age of 27, when he died from pneumonia.


Early automated manufacturing of insulin.

Click on the image to see in full size.

Click on the image to see in full size.