Who Discovered Insulin: A Concise Look at the Pioneers Behind the Breakthrough

Insulin's discovery in 1921 at the University of Toronto by Banting, Best, Collip, and Macleod turned diabetes from deadly to manageable.

The Discovery of Insulin

Key Figures in the Discovery

The discovery of insulin in 1921 was a major milestone in medical history, as it transformed diabetes from a fatal disease to a manageable condition.

The key figures in this discovery were Frederick Banting, Charles Best, James Collip, and John Macleod, all of whom were associated with the University of Toronto.

  • Frederick Banting: A Canadian orthopedic surgeon who came up with the idea to isolate insulin.
  • Charles Best: A student who assisted Banting with the experiments.
  • James Collip: A biochemist who played a crucial role in purifying insulin.
  • John Macleod: A physiology professor who guided and provided resources for the research.

Historical Context and Research Process

In the early 20th century, diabetes was a deadly disease with no effective treatment.

Banting hypothesized that a secreted substance from the pancreas could potentially regulate blood sugar levels in diabetic patients.

With the support of Macleod, Banting and Best began their research in 1921, focusing on the islets of Langerhans in the pancreas, which were thought to produce this substance.

The team’s groundbreaking work involved extracting, testing, and refining insulin from the pancreas of dogs.

This led to the development of the first effective treatment for diabetes.

Insulin Extraction and Purification

The process of extracting and purifying insulin was laborious and involved several steps:

  1. Surgically removing the pancreas from a test subject (initially dogs) and grinding it into a pulp.
  2. Filtering this extract to isolate the hormone.
  3. Collaborating with James Collip to further purify the hormone, eventually producing an effective insulin.

Banting and Best’s efforts, combined with Collip’s expertise in purification, eventually resulted in the creation of a successful treatment for diabetes.

First Clinical Applications and Leonard Thompson

After successful trials on animals, the first clinical application of insulin was administered to a 14-year-old patient named Leonard Thompson at Toronto General Hospital in 1922.

The treatment was a remarkable success, leading to significant improvements in Thompson’s blood sugar levels, and it marked the beginning of a new era in diabetes management.

For their discovery, Banting and Macleod were awarded the Nobel Prize in Physiology or Medicine in 1923.

Banting was gracious enough to share half of his prize money with Best, while Macleod shared his portion with Collip, recognizing the contributions of all team members in this historic medical advancement.

Insulin’s Impact and Advances in Diabetes Treatment

A vial of insulin sits beside a blood glucose monitor, symbolizing the impact and advances in diabetes treatment

Advancements in Insulin Therapy

The discovery of insulin in 1921 marked a significant milestone in the history of medicine, as it transformed type 1 diabetes from a fatal disease into a manageable condition1.

In the 1930s, researchers found that the action of insulin could be prolonged with the addition of protamine2.

Over the years, pharmaceutical companies like Eli Lilly introduced different forms of insulin, such as Humulin and Humalog.

Insulin therapy has come a long way since its initial discovery.

Today, patients with diabetes have access to various administration methods, including insulin pens and insulin pumps, which allow for more precise and convenient control of blood sugar levels.

Modern Diabetes Management and Technologies

Modern management of diabetes focuses on maintaining optimal glucose and blood sugar control.

Technology has played a crucial role in the development of new tools and techniques.

Advances in glucose monitoring systems, such as continuous glucose monitors (CGMs), can provide real-time information about blood sugar levels to help patients and healthcare providers make informed decisions about insulin doses and other treatments.

Additionally, insulin pumps and smart insulin pens have transformed the way insulin is administered, allowing for more personalized and accurate dosing.

Some insulin pumps can even connect with CGMs, creating a closed-loop system that adjusts insulin delivery based on glucose levels automatically.

Insulin Gene, Synthetic Production, and Future Prospects

The insulin gene has been well-researched, and understanding its expression and regulation has led to significant advances in the field.

In the late 1970s, scientists succeeded in synthesizing biosynthetic insulin using recombinant DNA technology, which allowed for more efficient mass production of the hormone.

Today, research is focused on developing even more advanced insulin therapies and diabetes management technologies.

Some potential future developments include the creation of smart insulin, which would only activate when blood sugar levels are high, and advances in cell-based therapies, such as pancreatic islet cell transplantation3.

These discoveries and advancements show the continuous endeavor of scientists and medical professionals to improve diabetes treatments.

The history of insulin and its impact on diabetes management is a testament to the power of collaboration and innovation in advancing the field of medicine.


  1. https://www.nature.com/articles/s41591-021-01418-2

  2. https://www.nature.com/articles/d42859-021-00004-3

  3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6205949/