From Insulin to GLP-1: Canada’s Century of Peptide Discovery

The first peptide hormone ever used as a medicine was purified in Toronto. A century later, Canadian laboratories are still behind a remarkable share of peptide science, from the hormones that regulate calcium to the GLP-1 biology behind today’s metabolic drugs.

This is that story, told through the discoveries, the people and the places, and connected to research peptides on the shelf today.

1921: insulin and the first peptide medicine

In 1921, Frederick Banting, a young surgeon from Alliston, Ontario, persuaded J.J.R. Macleod to lend him laboratory space at the University of Toronto. Working with student Charles Best, he prepared a pancreatic extract that lowered blood sugar in diabetic dogs. Biochemist James Collip then purified it enough to give to a person. In January 1922, 14-year-old Leonard Thompson, dying of diabetes at Toronto General Hospital, became the first person treated with insulin, and he recovered.

The 1923 Nobel Prize in Physiology or Medicine went to Banting and Macleod. Banting shared his prize money with Best, and Macleod shared his with Collip. The discoverers then sold the patent to the University of Toronto for a nominal sum so that insulin could be made widely available.

Insulin is a peptide: two chains of 21 and 30 amino acids joined by disulfide bridges. Its discovery showed that a peptide taken from tissue could be purified, standardized and used as a medicine, the template every peptide drug since has followed.

The calcium hormones: Edmonton and Vancouver

Collip returned from Toronto to the University of Alberta, where in 1925 he became the first to extract the active principle of the parathyroid glands, a hormone he named parathormone. The first injection of purified parathyroid hormone took place in the university’s Medical Building in Edmonton. Parathyroid hormone raises blood calcium, and modified fragments of it are still studied in bone research today.

Thirty-six years later, Harold Copp, the first head of physiology at the University of British Columbia, found the opposite signal. In 1961 his experiments revealed a previously unknown hormone that lowers blood calcium, which he named calcitonin. Calcitonin later became a treatment for bone diseases. It also founded a peptide family that includes amylin, which is why cagrilintide, a modern amylin analogue, acts partly on the calcitonin receptor.

Montreal’s hormone hunters

In the 1940s and 1950s, Hans Selye’s stress research made Montreal a magnet for endocrinologists. Roger Guillemin earned his PhD at the Université de Montréal in 1953 under Selye, and Andrew Schally completed his at McGill University in 1957. Both then moved to the United States and spent years in a fierce race to isolate the tiny peptide hormones the brain uses to control the pituitary.

They found them: TRH, then GnRH, and in Guillemin’s laboratory somatostatin. The 1977 Nobel Prize in Physiology or Medicine went to Guillemin and Schally for their discoveries concerning the peptide hormone production of the brain, shared with Rosalyn Yalow. In 1982 Guillemin’s team characterized growth hormone-releasing hormone (GHRH). Quebec-born Paul Brazeau, an author on both the somatostatin and GHRH papers, went on to co-found Montreal’s Theratechnologies, which developed the GHRH analogue tesamorelin. Our growth hormone peptides map follows that lineage to today’s research compounds.

Toronto and the GLP-1 era

In 1987, Daniel Drucker, then working in Joel Habener’s laboratory in Boston, co-authored a study showing that glucagon-like peptide-1 stimulates insulin gene expression in pancreatic cells. Back in Toronto, his laboratory showed in 1996 that the related hormone GLP-2 makes the intestinal lining grow, work that led to a medicine for short bowel syndrome. Drucker’s research at the Lunenfeld-Tanenbaum Research Institute helped lay the groundwork for the GLP-1 drugs that now dominate metabolic medicine.

The story has a 2026 coda: in April, Canada became the first G7 country to authorize a generic version of semaglutide, a GLP-1 medicine. Our GLP-1 research map covers where every compound in that class stands.

Research peptides with Canadian roots

• Tesamorelin, developed by Montreal’s Theratechnologies, was approved in the US in 2010 and by Health Canada in 2014 as Egrifta.
• CJC-1295 came from Montreal’s ConjuChem, whose Drug Affinity Complex technology bonds peptides to albumin. See peptide half-life engineering.
• SS-31 is one of the Szeto-Schiller peptides, co-developed by Peter W. Schiller of Montreal’s Institut de recherches cliniques. As elamipretide, it received US accelerated approval for Barth syndrome in 2025.
• LL-37 was recast as an immune modulator, not just a natural antibiotic, by Robert Hancock’s laboratory at UBC in 2002.
• Cagrilintide‘s 2021 phase 2 trial was led by David Lau of the University of Calgary.
• Peptide chemistry itself owes a debt to Ian Clark-Lewis of UBC, a co-author of the 1994 paper introducing native chemical ligation. See how research peptides are made.

TesamorelinA Montreal-developed GHRH analogueView product and COA SS-31Co-developed at Montreal’s IRCMView product and COA LL-37Reframed at UBC in 2002View product and COA CagrilintidePhase 2 led from CalgaryView product and COA

A century at a glance

1. 1921–22: insulin, TorontoBanting, Best, Collip and Macleod; the first patient is treated in January 1922.
2. 1925: parathyroid hormone, EdmontonCollip makes the first active extract at the University of Alberta.
3. 1950s: Montreal trains two future laureatesGuillemin (Université de Montréal, 1953) and Schally (McGill, 1957).
4. 1961: calcitonin, VancouverHarold Copp discovers a calcium-lowering hormone at UBC.
5. 1977: Nobel Prize for brain peptidesGuillemin and Schally share the prize with Rosalyn Yalow.
6. 1987 and 1996: GLP-1 and GLP-2Drucker’s work on insulin gene expression and intestinal growth.
7. 2002: LL-37 as immune modulatorHancock’s laboratory at UBC.
8. 2010 and 2014: tesamorelin approvedTheratechnologies’ GHRH analogue reaches patients in the US, then Canada.
9. 2021: cagrilintide phase 2Led by David Lau at the University of Calgary.
10. 2026: generic semaglutideCanada becomes the first G7 country to authorize one.

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