Buy GLP-3 Peptide in Canada — Retatrutide 5mg to 60mg Vials & Pen, Lab-Tested

Researched & reviewed by the SPO Quality Team · Last reviewed: 30 September 2026

What retatrutide is

Retatrutide (LY3437943) is a single synthetic peptide of 39 amino acids, designed by Eli Lilly to activate three receptors at once: the glucose-dependent insulinotropic polypeptide (GIP) receptor, the glucagon-like peptide-1 (GLP-1) receptor and the glucagon receptor^[1]. “GLP-3” is not a hormone and does not exist in the body; it is the catalogue name this site uses for the compound, and the batch report on the product page is titled “Retatrutide” for that reason. Retatrutide is an investigational drug: it has completed Phase 2 and has Phase 3 results published^{[4, 5, 9, 10]}, but as of this review it is not approved by Health Canada, the FDA or any other regulator. The vials on this page are research-grade material for in-vitro and preclinical laboratory work only. They are not the investigational drug used in those trials, and nothing reported below describes or supports them.

Key facts

• Class: triple GIP/GLP-1/glucagon receptor agonist; in vitro it shows balanced glucagon-receptor and GLP-1-receptor activity and stronger GIP-receptor activity^[1]
• Sequence: YAQGTFTSDYSILLDKKAQAAFIEYLLEGGPSSGAPPPS-NH₂ (39 residues), with 2-methylalanine (Aib) at positions 2 and 20, α-methyl-leucine at position 13, and a C20 fatty diacid attached to Lys17 through a γ-glutamyl–bis(2-aminoethoxy)acetyl linker — read from the USAN systematic name in the FDA GSRS record (UNII NOP2Y096GV)
• Molecular formula: C₂₂₁H₃₄₂N₄₆O₆₈ — PubChem CID 171390338
• Molecular weight: 4731 g/mol (PubChem); exact mass 4730.478. The FDA GSRS record carries an “estimated” 4091.5 Da / C₁₈₇H₂₈₁N₄₃O₆₀, which corresponds to the peptide chain without the lipid side-chain; both figures are shown because a mass-spectrometry identity check depends on which one is expected
• CAS number: 2381089-83-2 · UNII: NOP2Y096GV · ChEMBL: CHEMBL5095485 (protein class, max phase 3) · INN: list 12350
• Pharmacokinetics (human): a half-life of about six days^[2]
• Regulatory status: investigational, Phase 3; no approval anywhere as of 30 September 2026. Research-grade retatrutide has no approval for any use.
• Formats on this site: 5mg, 10mg, 20mg and 60mg vials and a pen — lyophilized powder, laboratory research only

Where does retatrutide come from?

The design follows the incretin-drug lineage: GLP-1 receptor agonists, then the dual GIP/GLP-1 agonist tirzepatide, then a molecule adding glucagon-receptor activity. The 2022 discovery paper describes the rationale: in obese mice, weight loss from reduced calorie intake (GIP and GLP-1 receptor signalling) was augmented by glucagon-receptor-mediated increases in energy expenditure, and a single ascending-dose Phase 1 study in humans showed a tolerability profile similar to other incretins with a pharmacokinetic profile suited to weekly dosing^[1]. Structural work published in 2024 used cryo-electron microscopy to show how one peptide engages all three receptors^[7]. Everything since has been clinical: Phase 1b in type 2 diabetes^[2], two Phase 2 programmes^{[4, 5]} with liver-fat and body-composition substudies^{[6, 8]}, and the first Phase 3 publications in 2026^{[9, 10]}.

Chemical identity

PubChem carries the compound under the title “Triple G” with retatrutide and its CAS number attached through deposited substance records; ChEMBL classes it as a protein and gives no weight. The weight discrepancy between PubChem and GSRS is explained above and matters for anyone reading a mass-spectrometry line on a certificate.

What has been studied

Animal and cell studies

The discovery paper reports lower body weight and improved glycaemic control in obese mice, with the glucagon-receptor component adding energy expenditure to the appetite effects of the other two receptors^[1]. A 2026 study in diet-induced obese MASH mice and hamsters recorded a 31% body-weight reduction in mice with reduced food and water intake and no significant change in energy expenditure, lower HOMA-IR, steatosis score and lipids; in hamsters, altered food preference, lower LDL and a 50% fall in hepatic triglyceride without a change in histopathological score^[11]. In mouse models of non-diabetic renal fibrosis (unilateral ureteral obstruction and ageing) and in HK-2 cells, retatrutide’s effects were associated with inhibition of PI3K-AKT and NF-κB pathways^[12]. Cryo-EM structures of the peptide bound to each of its three receptors were published in 2024^[7].

Human pharmacology (investigational drug)

In the 12-week Phase 1b trial (72 adults with type 2 diabetes), pharmacokinetics were dose-proportional with a half-life of about six days; gastrointestinal disorders were the most frequent adverse events, and 29 of 72 participants discontinued early^[2]. A separate pharmacology study measured delayed gastric emptying^[3].

Phase 2 randomised trials

The 48-week obesity trial (338 adults, NCT04881760) reported dose-dependent reductions in body weight versus placebo across its dose arms; adverse events were mostly gastrointestinal and rose with dose, and heart rate increased with dose, peaking at 24 weeks^[4]. The 36-week type 2 diabetes trial (281 adults, NCT04867785) reported dose-dependent HbA1c and body-weight reductions versus placebo and versus the comparator dulaglutide, with mild-to-moderate gastrointestinal adverse events in 35% of retatrutide participants^[5]. A liver-fat substudy (98 participants with MASLD) reported dose-dependent relative reductions in liver fat versus placebo at 24 weeks^[6]; a DXA substudy (189 participants) reported dose-dependent reductions in total fat mass versus placebo and dulaglutide^[8].

Phase 3 randomised trials (2026)

TRANSCEND-T2D-1 (537 adults with type 2 diabetes, 40 weeks) reported dose-dependent HbA1c and body-weight reductions versus placebo; discontinuations for adverse events were 2–5% versus 0%, and two deaths in one retatrutide group were judged unrelated^[9]. TRIUMPH-2 (1,152 adults with obesity and type 2 diabetes, 80 weeks) reported dose-dependent body-weight reductions versus placebo; diarrhoea (27–34% vs 13%), nausea (14–28% vs 8%), hypotension (1–6% vs under 1%) and dysesthesia (4–7% vs 1%) were more frequent on the drug, permanent discontinuation for adverse events reached 12% in one dose group, and seven deaths occurred across all groups, all judged unrelated by investigators^[10]. A 2026 meta-analysis pooled blood-pressure and lipid changes from the randomised trials^[14]; a 2025 systematic review covered three trials to March 2025^[13]; a 2026 overview summarises the programme^[15].

Products sold as “retatrutide” outside trials

Three 2026 papers concern the material now circulating outside the trial programme. An anti-doping group validated an LC-HRMS method after four self-administering users provided plasma and urine, noting “increasing off-label use among physically active populations” and finding the intact peptide undetectable in urine^[16]. An Australian letter analysed the composition and labelling accuracy of products sold as retatrutide^[17]. A case report describes a man with type 1 diabetes who developed severe vomiting, ketonaemia and acute kidney injury after self-administering an online-purchased product marketed as retatrutide, with the authors noting that such products’ “composition, purity and dosing accuracy may be uncertain”^[18]. These papers are the reason the batch report on each product page is shown in full.

Study summary

What the evidence does not show

• Nothing about research-grade vials. Every human number above was produced by Eli Lilly’s investigational product, manufactured to pharmaceutical standards and given under medical supervision inside registered trials. None of it describes, tests or supports the material sold here, and no weight, glucose, liver or any other effect is claimed for it.
• Not approved. Retatrutide has no marketing authorisation from Health Canada, the FDA or the EMA as of this review; Phase 3 publication is not approval^{[9, 10]}.
• Adverse events are real and dose-related. Gastrointestinal events in a third or more of participants, higher discontinuation at the higher doses, dose-dependent heart-rate increase, hypotension and dysesthesia were all recorded in the trials^{[4, 10]}; deaths occurred in both Phase 3 trials and were judged unrelated by investigators^{[9, 10]}.
• Online products are not the trial drug. A 2026 case report and a composition-accuracy study concern products marketed as retatrutide outside any trial^{[17, 18]}; a batch report addresses identity and purity of one lot, not safety or suitability for any use.
• Animal data are limited and mixed. The hamster study found no change in histopathological score despite lower liver triglyceride^[11]; the kidney-fibrosis work is described by its authors as hypothesis-generating^[12].
• Anti-doping. Detection methods for retatrutide in sport have been developed because of off-label use among active populations^[16].

Batch documentation

An independent Janoshik report titled “Retatrutide” is posted for the 10mg vial: report #232263, sample received 16 September 2026, analysed 21 September 2026, measured content 9.24 mg against a 10 mg label, purity 99.079%, verification key LBUI98X8TRUG. The same document is listed in the COA library for the 10mg pen. The 5mg, 20mg and 60mg vials have no posted report at the time of this review; their product pages say so. The report identifies the sample within Janoshik’s “common GLP-1 peptide blind test” panel (semaglutide, tirzepatide, retatrutide), which is the identity check that distinguishes retatrutide from the other two.

Retatrutide is one of the compounds listed on the page where you can buy peptides online in Canada; each listing there carries the same research-use-only terms and links to its own batch documentation.

Handling and storage in the laboratory

• Form: lyophilized powder in a sealed vial.
• Storage: the site’s guidance is −20 °C for long-term storage of the sealed vial (stated stability up to 24 months) and cool, dry, dark conditions for short periods; avoid repeated freeze–thaw.
• Solutions: reconstituted solutions are less stable than powder; prepare only what an experiment needs. Trial pharmacokinetics (a six-day half-life, depot-like absorption)^{[2, 16]} describe the drug in people, not the stability of a solution on a bench.
• Protocols: the researcher’s responsibility. Shop Peptides Online publishes no dosing, reconstitution or administration guidance.

References

All references were retrieved from PubMed (NCBI) on 30 September 2026 and cross-checked against Europe PMC; identity data from PubChem, the FDA Global Substance Registration System and ChEMBL (EMBL-EBI) on the same date.

1. Coskun T, Urva S, Roell WC et al. (2022). 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 34(9):1234-1247.e9. doi:10.1016/j.cmet.2022.07.013. PMID 35985340
2. Urva S, Coskun T, Loh MT et al. (2022). LY3437943, a novel triple GIP, GLP-1, and glucagon receptor agonist in people with type 2 diabetes: a phase 1b, multicentre, double-blind, placebo-controlled, randomised, multiple-ascending dose trial. Lancet (London, England) 400(10366):1869-1881. doi:10.1016/S0140-6736(22)02033-5. PMID 36354040
3. Urva S, O'Farrell L, Du Y et al. (2023). The novel GIP, GLP-1 and glucagon receptor agonist retatrutide delays gastric emptying. Diabetes, obesity & metabolism 25(9):2784-2788. doi:10.1111/dom.15167. PMID 37311727
4. Jastreboff AM, Kaplan LM, Frías JP et al. (2023). Triple-Hormone-Receptor Agonist Retatrutide for Obesity – A Phase 2 Trial. The New England journal of medicine 389(6):514-526. doi:10.1056/NEJMoa2301972. PMID 37366315
5. Rosenstock J, Frias J, Jastreboff AM et al. (2023). Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial conducted in the USA. Lancet (London, England) 402(10401):529-544. doi:10.1016/S0140-6736(23)01053-X. PMID 37385280
6. Sanyal AJ, Kaplan LM, Frias JP et al. (2024). Triple hormone receptor agonist retatrutide for metabolic dysfunction-associated steatotic liver disease: a randomized phase 2a trial. Nature medicine 30(7):2037-2048. doi:10.1038/s41591-024-03018-2. PMID 38858523
7. Li W, Zhou Q, Cong Z et al. (2024). Structural insights into the triple agonism at GLP-1R, GIPR and GCGR manifested by retatrutide. Cell discovery 10(1):77. doi:10.1038/s41421-024-00700-0. PMID 39019866
8. Coskun T, Wu Q, Schloot NC et al. (2025). Effects of retatrutide on body composition in people with type 2 diabetes: a substudy of a phase 2, double-blind, parallel-group, placebo-controlled, randomised trial. The lancet. Diabetes & endocrinology 13(8):674-684. doi:10.1016/S2213-8587(25)00092-0. PMID 40609566
9. Bajaj HS, Welch M, Shah P et al. (2026). Efficacy and safety of retatrutide, a GIP, GLP-1, and glucagon receptor agonist, in people with type 2 diabetes and inadequate glycaemic control with diet and exercise (TRANSCEND-T2D-1): a double-blind, randomised, phase 3 trial. Lancet (London, England) 407(10546):2402-2413. doi:10.1016/S0140-6736(26)00967-0. PMID 42250575
10. Bellido V, le Roux CW, Ekinci EI et al. (2026). Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, parallel-group, randomised, placebo-controlled, phase 3 trial. Lancet (London, England) . doi:10.1016/S0140-6736(26)01861-1. PMID 42810372
11. Briand F, Le Cudennec C, Grasset E et al. (2026). Retatrutide Shows Multiple Metabolic Benefits in Diet-Induced Obese MASH Mouse and Hamster Models. Obesity (Silver Spring, Md.) 34 Suppl 1(Suppl 1):43-53. doi:10.1002/oby.70155. PMID 41741376
12. Ding M, Li X, Wei Y et al. (2026). Comparative effects of semaglutide tirzepatide and retatrutide on renal fibrosis in UUO and aged mice. iScience 29(9):117174. doi:10.1016/j.isci.2026.117174. PMID 42630988
13. Misra S, Narayan RK, Kaur M (2025). Efficacy and safety of retatrutide for the treatment of obesity: a systematic review of clinical trials. Journal of basic and clinical physiology and pharmacology 36(4):263-274. doi:10.1515/jbcpp-2025-0113. PMID 40728138
14. Simental-Mendía LE, Barragán-Zúñiga LJ, Reyes-Avitia V (2026). Effect of Retatrutide, a Novel Triple Receptor Agonist, on Blood Pressure and Lipid Levels: A Systematic Review and Meta-analysis of Randomized Controlled Trials. High blood pressure & cardiovascular prevention : the official journal of the Italian Society of Hypertension 33(5):503-516. doi:10.1007/s40292-026-00812-6. PMID 42371360
15. Panou T, Gouveri E, Popovic DS et al. (2026). Retatrutide in type 2 diabetes mellitus and obesity: an overview. Expert review of clinical pharmacology 19(4):313-339. doi:10.1080/17512433.2026.2642415. PMID 41785010
16. Carneiro GRA, da Costa Nunes IK, Dos Santos Cardoso GR et al. (2026). Detection and Excretion Profile of Retatrutide in Human Plasma and Urine by LC-HRMS: Implications for Antidoping Analysis. Rapid communications in mass spectrometry : RCM 40(23):e70179. doi:10.1002/rcm.70179. PMID 42745421
17. Piatkowski T, Craven A, Cornell S et al. (2026). Composition and Labelling Accuracy of Products Sold as Retatrutide in Australia. Drug and alcohol review 45(6):e70231. doi:10.1111/dar.70231. PMID 42559975
18. Branine N (2026). Online-Sourced Retatrutide Complicating Impending Diabetic Ketoacidosis in a Patient With Type 1 Diabetes and Concurrent Shigella Gastroenteritis. Cureus 18(8):e115260. doi:10.7759/cureus.115260. PMID 42669023