By the Boreal Peptides Research Team | Reviewed by Boreal Peptides Owner | Last reviewed October 22, 2026 | 18 sources | For laboratory research use only

Quick answer

GLP-1 peptides are peptides that switch on the receptor for glucagon-like peptide-1, a gut hormone. Some act on that receptor only, but others also act on GIP or glucagon receptors. In Canada, semaglutide and tirzepatide are prescription drugs authorized by Health Canada. Retatrutide is still investigational, and research-grade versions aren’t authorized drugs. [1][2][7][14]

Key facts

  • Natural GLP-1 has a half-life of about 1 to 2 minutes, depending on the species. An enzyme and the kidneys clear it. [3]

  • Health Canada says semaglutide and tirzepatide drugs “are prescription drugs authorized by Health Canada.” [1]

  • Tirzepatide acts on two receptors (GIP and GLP-1). Retatrutide acts on three (GIP, GLP-1 and glucagon). [5][7]

  • Retatrutide is investigational. Its maker says it “cannot be legally sold or marketed for human use.” [7]

  • Health Canada says a “research use only” label doesn’t make a product legal. [14]

At a glance Summary
Central entity Glucagon-like peptide-1 (GLP-1) and the drugs built on it
What “GLP-1 peptide” usually means A peptide that activates the GLP-1 receptor, alone or with other receptors [3][5][7]
Authorized in Canada Semaglutide, tirzepatide, liraglutide and dulaglutide products, among others, all prescription [2]
Investigational, not authorized Retatrutide (in phase 3 trials) [7]
Research-grade versions Not authorized drugs in Canada; a research label doesn’t change that [1][14]
A sealed glass vial of white freeze-dried powder on a dark green surface
Illustrative image. Research-grade peptides aren’t the same products as authorized prescription drugs.

What are GLP-1 peptides?

GLP-1 peptides are peptides that act on the receptor for glucagon-like peptide-1, a hormone made in the gut. A peptide is a short chain of amino acids. The term covers the natural hormone and drugs built to switch on its receptor, and some act on two or three receptors. [3][5][7]

The body makes GLP-1 in L-cells, mostly in the lower gut. Its gene is also active in pancreatic alpha cells, and in some brainstem neurons. [3] It’s cut from a larger protein called proglucagon, which also yields glucagon and a second peptide, GLP-2. [3]

In people, about 80% of circulating GLP-1 is a form called GLP-1 (7-36) amide. The other 20% is GLP-1 (7-37). [3] Because it boosts insulin release when blood sugar is high, GLP-1 is an incretin. That’s a gut hormone that responds to food. [3]

What’s a receptor agonist? It’s a molecule that switches a receptor on. So a “GLP-1 receptor agonist” turns on the GLP-1 receptor. That’s the formal name for most of the drugs below.

Are GLP-1 drugs peptides?

Most of them are. Semaglutide and liraglutide are modified versions of human GLP-1. [4] Exenatide is a 39-amino-acid peptide first found in Gila monster saliva. [3] Tirzepatide and retatrutide are single peptides, yet each acts on more than one receptor. [5][6][7] Orforglipron is the exception: it’s a non-peptide small molecule. [9]

So “GLP-1 vs peptides” isn’t a true contrast, because GLP-1 drugs are mostly a group within peptides. What sets one apart from another? It’s the receptor it targets, how long it lasts, and whether a regulator has authorized it.

Why doesn’t natural GLP-1 last long in the body?

An enzyme called DPP-4 (dipeptidyl peptidase-4) cuts the natural hormone within minutes, and the kidneys clear it too. Native GLP-1 has a half-life of about 1 to 2 minutes, depending on the species. [3] Since that’s far too short for a drug, chemists changed the molecule.

Here are the main changes researchers made to keep GLP-1 working longer. [3][4]

Design change Example What it does Source
Swap the amino acid DPP-4 cuts Semaglutide (Aib at position 8) Protects the peptide from DPP-4 while keeping receptor binding [4]
Attach a fatty acid chain Liraglutide (16-carbon palmitate), semaglutide (18-carbon di-acid) Binds blood albumin, so the peptide is cleared slowly [4]
Start from a different animal peptide Exenatide (from exendin-4) Exendin-4’s first 30 amino acids match human GLP-1 at about 53%, and it resists DPP-4 [3][4]

Exendin-4 was first found in the saliva of the Gila monster, a venomous lizard. [3][4] One branch of this drug family started in reptile biology, not in a chemistry lab.

Close view of a Gila monster's head with orange and black scales
Exendin-4, the starting point for exenatide, was first found in Gila monster saliva. Photo: Jeff Servoss, public domain, via Wikimedia Commons (cropped and resized).

What is the difference between single, dual and triple agonists?

It’s the number of hormone receptors one molecule switches on. Semaglutide acts on the GLP-1 receptor alone, while tirzepatide acts on two: GIP and GLP-1. Retatrutide goes one step further, and it acts on GIP, GLP-1 and glucagon receptors together. [4][5][7] GIP (glucose-dependent insulinotropic polypeptide) is a second gut hormone linked to the incretin effect. [3]

The mix matters. When Lilly scientists studied tirzepatide in 2020, they used cell assays and receptor-occupancy estimates. They found it engages the GIP receptor more than the GLP-1 receptor, so they called it “imbalanced.” [5] For retatrutide, lab tests showed balanced glucagon and GLP-1 receptor activity, with more GIP receptor activity. [6]

This table sorts the main compounds you’ll see named online. Where it gives a Canadian status, that comes from Health Canada’s Drug Product Database, searched October 22, 2026. [2]

Compound Receptor targets Peptide? Research stage Canada status Source
Semaglutide GLP-1 Yes Authorized drug Prescription, several brands and 2026 generics [1][2][4]
Liraglutide GLP-1 Yes Authorized drug Prescription (Victoza, Saxenda) [2][4]
Dulaglutide GLP-1 Two GLP-1 peptides fused to an antibody fragment Authorized drug Prescription (Trulicity) [2][3]
Exenatide GLP-1 Yes (from exendin-4) Authorized in the past Canadian products cancelled after market in 2022 [2][3]
Tirzepatide GIP and GLP-1 Yes Authorized drug Prescription (Mounjaro, Zepbound) [1][2][5]
Survodutide Glucagon and GLP-1 Yes Phase 3 trials in people Not in the Drug Product Database [2][10]
Mazdutide GLP-1 and glucagon Yes Approved in China in June 2025 Not in the Drug Product Database [2][11][18]
Retatrutide GIP, GLP-1 and glucagon Yes Phase 3 trials in people Not in the Drug Product Database; investigational [2][6][7]
Orforglipron GLP-1 No (small molecule) Sold in the US as Foundayo Not in the Drug Product Database [2][7][9][16]
Cagrilintide Amylin and calcitonin, not GLP-1 Yes Mouse studies; drugs of its type are in phase 2 and 3 trials Not in the Drug Product Database [2][8]

Cagrilintide often sits next to GLP-1 compounds in shops, ours included, but it isn’t one. Researchers describe it as a dual amylin and calcitonin receptor agonist. [8] The 2025 mechanism study cited here was done in mice. [8]

Which GLP-1 drugs are authorized in Canada?

Semaglutide and tirzepatide products are. Health Canada names semaglutide (Ozempic, Rybelsus, Wegovy) and tirzepatide (Mounjaro, Zepbound). It says they “are prescription drugs authorized by Health Canada to treat type 2 diabetes and obesity.” [1] Liraglutide and dulaglutide products are authorized too. [2]

We searched every GLP-1 ingredient in the Drug Product Database on October 22, 2026. The status column uses the database’s own labels, and some strengths of a brand can carry a different status. [2]

Ingredient Brand or product (company) Database status, October 22, 2026
Semaglutide Ozempic, Rybelsus, Wegovy (Novo Nordisk) Marketed (first marketed 2018, 2020 and 2024)
Semaglutide Semaglutide Injection (Dr. Reddy’s), Apo-Semaglutide Injection (Apotex) Marketed since May 2026
Semaglutide Sandoz Semaglutide, Aspen-Semaglutide, Sevmia (Apotex), Plosbrio and Poviztra (Novo Nordisk) Approved, not yet marketed
Tirzepatide Mounjaro, Mounjaro KwikPen, Zepbound (Eli Lilly) Marketed
Liraglutide Victoza, Saxenda (Novo Nordisk) Marketed since 2010 and 2015; Xultophy (with insulin degludec) cancelled after market, 2025
Dulaglutide Trulicity (Eli Lilly) Marketed since 2015
Exenatide Byetta, Bydureon (AstraZeneca) Cancelled after market, 2022
Lixisenatide Adlyxine (Sanofi) Cancelled after market, 2023; Soliqua (with insulin glargine) still marketed
Retatrutide, cagrilintide, survodutide, mazdutide, orforglipron No product No entry

Each authorized product has an eight-digit Drug Identification Number (DIN), and every record we opened lists its schedule as “Prescription.” [2] Want to check one? Health Canada advises looking up the DIN in the database. It also says to buy only from licensed pharmacies. [1]

For the legal side of peptides in general, read our guide: Are peptides legal in Canada?

Plain prescription bag and medicine box on a pharmacy counter
Illustrative image. Authorized GLP-1 drugs in Canada are prescription products with a DIN.

What does the research on GLP-1 peptides actually cover?

It runs in three stages: cells, animals, then people. Each stage tells you more about people than the last. Still, a study in cells or rodents isn’t a statement about people. [6][17]

Retatrutide’s discovery paper shows all three in one place. [6]

Evidence level What it tests Example Source
Cells (in vitro) Which receptors a molecule switches on, and how strongly Retatrutide’s receptor activity measured in lab assays; tirzepatide’s receptor bias [5][6]
Animals What happens in a whole living system Retatrutide in mice; cagrilintide in mice lacking certain amylin receptors [6][8]
People, phase 1 Safety, tolerability and how long a drug lasts Retatrutide single-dose study [6]
People, phase 2 and 3 Whether a drug meets a trial’s pre-set goals, in larger groups Retatrutide, survodutide and mazdutide phase 3 trials [7][10][11]
Regulator review Safety, efficacy and quality of a finished product Health Canada authorization with a DIN [1][2]

Which conditions? Each trial sets its own. Lilly says retatrutide is in phase 3 trials in seven study areas, such as type 2 diabetes. [7] A trial area isn’t a result, though. In July 2026, Lilly said detailed results from two of those trials would appear in journals later. [7]

We don’t report trial outcomes, doses or effects here; those belong to prescribers and to the published papers.

Is “GLP-3” a real peptide?

No. There’s no hormone called GLP-3, since the proglucagon gene codes for two glucagon-like peptides: GLP-1 and GLP-2. [3] “GLP-3” is an informal nickname for retatrutide, which acts on three receptors. [16] It isn’t an official drug class, and the medical community doesn’t use it. [16]

The number in “GLP-1” is part of the hormone’s name, and it doesn’t count receptors. A dual agonist isn’t a “GLP-2,” and retatrutide isn’t a “GLP-3” either. [3][16] Lilly calls it a “triple hormone receptor agonist.” [7]

If you see “GLP-3” on a vial label, it’s an informal nickname, and it doesn’t prove what’s in the vial. Only a named compound, a batch and a certificate can do that.

Is research-grade semaglutide the same as Ozempic?

No. A shared molecule name doesn’t make a shared product. An authorized drug has passed Health Canada’s review for safety, effectiveness and quality, and it carries a DIN. [1][2] A research-grade vial hasn’t passed that review. It has no DIN. [14][17]

Regulators on both sides of the border say this directly, so we’ll quote them:

  • Health Canada says unauthorized GLP-1 products haven’t been assessed for safety, effectiveness or quality, and advises people not to buy or use them. [1]

  • Health Canada says a “For Research Use Only” label “does not make these products legal or exempt from regulatory requirements.” [14]

  • The US FDA has warned companies that sold semaglutide, tirzepatide, retatrutide, survodutide or mazdutide falsely labelled “for research purposes.” [12]

  • The FDA says retatrutide and cagrilintide “have not been found safe and effective for any condition.” [12]

In 2025, Health Canada named retatrutide and tirzepatide on a list of unauthorized injectable peptide drugs. They’d been seized from or sold by one Canadian seller. [13] Retatrutide is listed again in its April 2026 advisory. [14]

We sell research-grade retatrutide, tirzepatide, semaglutide and cagrilintide, so this applies to us. Our research use disclaimer says nothing on our site is authorized for sale as a drug in Canada, and no product carries a DIN. [17]

What do our own tests show for GLP-1 compounds?

One of our four GLP-1 and metabolic compounds has a third-party certificate, but three don’t. We’d rather say that than quote a supplier’s own purity claim. [15]

Published testing data: Boreal Peptides

  • Retatrutide: 99.562% purity, Janoshik, report #51431, batch GYC42DWH, issued February 21, 2026. It covers that batch only. [15]
  • Semaglutide, tirzepatide, cagrilintide: no third-party certificate. Each product page says “not tested”. [15]
  • Method: an HPLC assay of identity and purity in the tested sample. It doesn’t cover sterility, endotoxin, heavy metals, residual solvents or safety in anything living. None of our products is supplied sterile. [15]
  • What a purity result doesn’t mean: it’s a chemistry result, not a sign that a compound is safe or authorized. [15][17]

To get the report, name the compound. If you’ve already ordered, include your order number, and we’ll match it to the batch on your packing slip. [15]

See every lab result we hold | Read how to read a peptide COA

People also ask

Is GLP-1 a hormone or a peptide?

It’s both. GLP-1 is a peptide hormone that the gut releases after eating, and it boosts insulin release when blood sugar is high. [3]

Read more: What are GLP-1 peptides?

Where is GLP-1 made in the body?

Mostly in L-cells of the lower small intestine and colon. The gene behind it is also active in pancreatic alpha cells and some brainstem neurons. [3]

Is cagrilintide a GLP-1?

No. Researchers describe cagrilintide as a dual amylin and calcitonin receptor agonist. It isn’t a GLP-1 receptor agonist, though shops often list it with them. [8]

Read more: What is the difference between single, dual and triple agonists?

What is the difference between GLP-1 and GLP-2?

Both are cut from the same precursor protein, proglucagon. [3] They’re separate peptides. The drugs in this guide target the GLP-1 receptor, not GLP-2’s.

Are GLP-1 peptides approved?

Some are. Health Canada has authorized semaglutide and tirzepatide products as prescription drugs. Retatrutide is still investigational, and research-grade versions of any of them aren’t authorized drugs. [1][7][14]

Read more: Which GLP-1 drugs are authorized in Canada?

Sources and methodology

This guide draws on Health Canada advisories and its Drug Product Database, searched for every GLP-1 ingredient on October 22, 2026. It also uses the US FDA, peer-reviewed papers, the developer’s trial announcement and our own testing records. Claims are linked to numbered sources below. It contains no dosing information and makes no claim that any compound treats, prevents or improves any condition.

How this guide was made: we researched and drafted it with AI assistance. We then checked every claim against its cited source, and the owner of Boreal Peptides reviewed it before publication.

Last reviewed: October 22, 2026. Next review: January 2027, or sooner when Health Canada authorizes a new GLP-1 product or retatrutide is filed. Read our editorial policy.

Research use only

Boreal Peptides supplies compounds for laboratory research use only. Not for human or veterinary use. Nothing here is medical advice. Read our research use disclaimer.

Sources

  1. Health Canada. Thinking about buying GLP-1 drugs like Ozempic or Mounjaro? Beware of fake or unauthorized products (RA-81518). January 21, 2026. https://recalls-rappels.canada.ca/en/alert-recall/thinking-about-buying-glp-1-drugs-ozempic-or-mounjaro-beware-fake-or-unauthorized
  2. Health Canada. Drug Product Database, searched by active ingredient (semaglutide, tirzepatide, liraglutide, dulaglutide, exenatide, lixisenatide, retatrutide, cagrilintide, survodutide, mazdutide, orforglipron), October 22, 2026. https://health-products.canada.ca/dpd-bdpp/
  3. Müller TD, Finan B, Bloom SR, et al. Glucagon-like peptide 1 (GLP-1). Molecular Metabolism, 2019. doi:10.1016/j.molmet.2019.09.010. https://pubmed.ncbi.nlm.nih.gov/31767182/
  4. Knudsen LB, Lau J. The discovery and development of liraglutide and semaglutide. Frontiers in Endocrinology, 2019. doi:10.3389/fendo.2019.00155. https://pubmed.ncbi.nlm.nih.gov/31031702/
  5. Willard FS, Douros JD, Gabe MB, et al. Tirzepatide is an imbalanced and biased dual GIP and GLP-1 receptor agonist. JCI Insight, 2020. doi:10.1172/jci.insight.140532. https://pubmed.ncbi.nlm.nih.gov/32730231/
  6. Coskun T, Urva S, Roell WC, et al. LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss: from discovery to clinical proof of concept. Cell Metabolism, 2022. doi:10.1016/j.cmet.2022.07.013. https://pubmed.ncbi.nlm.nih.gov/35985340/
  7. Eli Lilly and Company. Lilly’s triple agonist retatrutide successful in two additional Phase 3 obesity trials (news release). July 23, 2026. https://www.prnewswire.com/news-releases/lillys-triple-agonist-retatrutide-successful-in-two-additional-phase-3-obesity-trials-delivering-significant-improvements-in-weight-and-a1c-302832674.html
  8. Carvas AO, Leuthardt A, Kulka P, et al. Cagrilintide lowers bodyweight through brain amylin receptors 1 and 3. EBioMedicine, 2025. doi:10.1016/j.ebiom.2025.105836. https://pubmed.ncbi.nlm.nih.gov/40609154/
  9. Ramadurgum P, Shah J, Shah E, Palmer BF. Potential nephroprotective mechanisms of orforglipron, an oral non-peptide GLP-1 receptor agonist. Frontiers in Pharmacology, 2026. doi:10.3389/fphar.2026.1917800. https://pubmed.ncbi.nlm.nih.gov/42582425/
  10. le Roux CW, Wharton S, Startseva E, et al. Survodutide once weekly for the treatment of adults with obesity. New England Journal of Medicine, 2026. doi:10.1056/NEJMoa2600751. https://pubmed.ncbi.nlm.nih.gov/42253238/
  11. Ji L, Jiang H, Bi Y, et al. Once-weekly mazdutide in Chinese adults with obesity or overweight. New England Journal of Medicine, 2025. doi:10.1056/NEJMoa2411528. https://pubmed.ncbi.nlm.nih.gov/40421736/
  12. US Food and Drug Administration. FDA’s concerns with unapproved GLP-1 drugs used for weight loss. Content current as of October 1, 2026. https://www.fda.gov/drugs/drug-alerts-and-statements/fdas-concerns-unapproved-glp-1-drugs-used-weight-loss
  13. Health Canada. Unauthorized injectable peptide drugs seized and sold by Canada Peptide may pose serious health risks (RA-77807). August 1, 2025. https://recalls-rappels.canada.ca/en/alert-recall/unauthorized-injectable-peptide-drugs-seized-and-sold-canada-peptide-may-pose-serious
  14. Health Canada. Think twice before injecting peptides bought online: unauthorized products can seriously harm you (RA-81874). April 9, 2026. https://recalls-rappels.canada.ca/en/alert-recall/think-twice-injecting-peptides-bought-online-unauthorized-products-can-seriously-harm
  15. Boreal Peptides. Lab results (checked October 22, 2026). https://borealpeptides.com/lab-results/
  16. Willson A, reviewed by Mansour M, MD. What is a GLP-3? GLP-3 drugs, explained. Ro, updated August 26, 2026. https://ro.co/weight-loss/what-is-a-glp-3/
  17. Boreal Peptides. Research use disclaimer (checked October 22, 2026). https://borealpeptides.com/research-use-disclaimer/
  18. Shanghai Municipal People’s Government (english.shanghai.gov.cn). Weight loss medicine Mazdutide approved for commercialization in China. July 2, 2025. https://english.shanghai.gov.cn/en-Latest-WhatsNew/20250702/110d07c0955546378d8ace318a418e6b.html
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About Boreal Peptides

The Boreal Peptides Research Team researches and writes our compound guides. Every guide is checked against the sources it cites and reviewed by the owner of Boreal Peptides before publication.

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