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Leonard Thompson: The 14-Year-Old Who Became the First Person Treated With Insulin
In the winter of 1921 to 1922, Leonard Thompson was a 14-year-old boy lying in a ward at Toronto General Hospital, weighing about 65 pounds and fading from diabetes. The only treatment available was a near-starvation diet. On January 11, 1922, he received an injection of a pancreatic extract that had never been given to a person before. It contained the peptide hormone insulin, and it nearly did not work.
Key takeaways
- Leonard Thompson was the first patient to receive insulin, in Toronto in January 1922.
- The first extract was so impure that it caused an abscess and did little for his blood sugar.
- A purified extract, prepared by the biochemist James Collip, was given less than two weeks later and worked dramatically.
- Thompson lived on insulin for about thirteen more years and died of pneumonia at 27.
- The story is a clear example of why purity matters for any peptide, as in our purity guide.
Life before insulin
Before 1922, a child with what we now call type 1 diabetes usually had a short future. The best available treatment, developed by physician Frederick Allen, was to cut food so severely that the body produced less sugar. Patients lived longer than they otherwise would, but they wasted away. Thompson, diagnosed as a young teenager, had reached the point where he was close to death.
The first injection
The extract had been prepared in the University of Toronto laboratory of John Macleod by Frederick Banting and his student Charles Best, who had reportedly tried small amounts on each other first. On January 11, 1922, doctors injected Thompson with it.
The result was disappointing. His blood sugar fell only a little, and the extract caused a sterile abscess at the injection site. It contained the active hormone, but mixed with so many other substances from the pancreas that it was hard to give a useful dose without side effects. The team decided not to continue until the material could be cleaned up.
The second try
In the following days, the biochemist James Collip, who had joined the group, worked to purify the extract. On January 23, Thompson received a new preparation. Contemporary reports describe a rapid change: his blood sugar fell sharply, and the ketones that signal dangerous metabolic breakdown cleared. Within days he was brighter, hungrier and stronger.
The peptide was the same in both injections. The difference was how much else was in the vial. That is a point we return to often in our posts on HPLC versus mass spectrometry and batch-specific lab reports.
The years that followed
Thompson went home and continued daily insulin injections. He lived until 1935, when he died of pneumonia at age 27. In the years between, insulin had become available worldwide, and children in similar condition in other hospitals were waking from comas after their first doses.
What the story teaches about peptides
- Identity alone is not enough: a peptide can be correct and still unusable if the sample is crude.
- Potency and purity are separate questions, and both must be measured.
- Injection-site reactions in the story were a consequence of impurities, a theme explored in our immunogenicity post.
- A hormone with a short life in the body needed careful handling and dosing, ideas covered in our pharmacokinetics glossary.
The bottom line
Leonard Thompson was the first of millions of people whose lives were changed by a peptide. His two injections, sixteen days apart, show that the quality of the material is as important as the molecule. Read more peptide history in our history of peptide drugs, and see how we document our own research compounds on the lab reports page.
Related reading
- History of peptide drugs
- Why purity alone is not enough
- Batch-specific lab reports
- Browse the full Research Library
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For laboratory research use only. Not for human or veterinary use, and not intended to diagnose, treat, cure or prevent any condition. This article is educational and is not medical advice.