Lilly's retatrutide shows double the weight loss of Ozempic in new trial: what it means for Canadian GLP-1 access

This article is for informational purposes only and is not medical advice. Consult your Canadian healthcare provider about your situation.

A clinical trial reported by Reuters on October 28, 2026 found that retatrutide, an investigational drug from Eli Lilly, produced substantially greater weight loss and blood sugar reduction than semaglutide (sold in Canada as Ozempic for type 2 diabetes and Wegovy for chronic weight management) in adults with obesity or type 2 diabetes. The trial has not yet been published in full peer-reviewed form, and the detailed dataset has not been independently verified by Health Canada or any Canadian clinical body as of this writing.

For a Canadian patient already on semaglutide or tirzepatide (sold in Canada as Mounjaro), the immediate practical answer is straightforward: retatrutide is not available here. Health Canada has not approved it, no Notice of Compliance has been issued, and Eli Lilly Canada has not announced a Canadian regulatory submission date. That means no provincial pharmacare plan, including Ontario's OHIP-adjacent Trillium Drug Program, Quebec's RAMQ, British Columbia's PharmaCare, or Alberta's AHCIP, covers it. The only path to access in Canada right now is enrollment in a registered clinical trial.

What this means in Canada

Retatrutide is a triple agonist, meaning it activates three hormone receptors simultaneously: GLP-1 (glucagon-like peptide-1), GIP (glucose-dependent insulinotropic polypeptide), and the glucagon receptor. That third target, the glucagon receptor, is what separates it from both semaglutide (a GLP-1 agonist only) and tirzepatide (a dual GLP-1/GIP agonist). The glucagon component is thought to increase energy expenditure, which may explain the larger weight-loss numbers seen in the trial.

In the United States, retatrutide remains under FDA review and has not received FDA approval as of October 2026. Health Canada operates its own independent review process and typically issues its own decision after reviewing a full submission package from the manufacturer. Eli Lilly has not publicly confirmed when or whether it will file with Health Canada. Until a Notice of Compliance is granted, Canadian physicians cannot prescribe it, and Canadian pharmacies cannot dispense it.

The Society of Obstetricians and Gynaecologists of Canada (SOGC) has not issued a position statement on retatrutide. The Obesity Canada clinical practice guidelines, last updated in 2020 and under revision, do not yet address triple agonists. No CMAJ (Canadian Medical Association Journal) editorial on retatrutide has been published as of this article's date.

For Canadians currently on semaglutide or tirzepatide, provincial coverage varies considerably. Ozempic (semaglutide 0.5 mg to 2 mg, indicated for type 2 diabetes) is listed on most provincial formularies when prescribed for diabetes. Wegovy (semaglutide 2.4 mg, indicated for chronic weight management) has Health Canada approval but remains off formulary in most provinces, meaning patients pay out of pocket, typically $300 to $500 CAD per month. Mounjaro (tirzepatide) received Health Canada approval for type 2 diabetes in 2023 and is listed on some provincial formularies for that indication. Coverage for obesity without diabetes is inconsistent across every province.

What changed

The Reuters report, citing trial data presented at a medical conference, described retatrutide participants losing approximately 24 percent of body weight over roughly 48 weeks, compared to roughly 12 to 15 percent seen in semaglutide trials of similar duration. Blood sugar reductions were also reported as superior. These are headline numbers from a single trial and have not yet been subjected to full peer review or meta-analysis.

The significance for the GLP-1 drug class is real: each generation of these drugs has produced meaningfully larger weight-loss results than the last, from liraglutide (sold in Canada as Saxenda) at roughly 5 to 8 percent, to semaglutide at 12 to 15 percent, to tirzepatide at 15 to 22 percent in the SURMOUNT trials. If retatrutide's numbers hold up across larger and longer studies, it would represent another step in that progression.

Eli Lilly's share price and pipeline positioning are relevant context: the company has a commercial interest in generating positive press around retatrutide ahead of any regulatory submission. That does not make the trial data false, but it is a reason to wait for peer-reviewed publication and independent replication before drawing firm conclusions.

What Canadian patients should know

If you are currently on semaglutide or tirzepatide and managing well, there is no clinical reason to seek a switch based on this trial alone. Retatrutide is not available to you through any legal Canadian channel.

If you are not yet on a GLP-1 medication and are interested in weight management or type 2 diabetes treatment, the drugs that do exist in Canada and have Health Canada approval are semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro). A family physician, endocrinologist, or a Canadian telehealth platform such as Felix, Maple, or Science & Humans (scienceandhumans.com) can assess whether you qualify and discuss coverage options.

Patients in provinces with limited formulary coverage for obesity indications may face significant out-of-pocket costs regardless of which drug is prescribed. Quebec's RAMQ covers Ozempic for type 2 diabetes but not for obesity alone. Ontario's Trillium Drug Program covers it for diabetes under specific criteria. British Columbia PharmaCare and Alberta AHCIP follow similar patterns. None of these plans currently cover Wegovy for obesity as a standard listed benefit, though special authority processes exist in some provinces.

Clinical trials for retatrutide may be recruiting in Canada. Clinicaltrials.gov lists active Eli Lilly retatrutide studies, and some Canadian sites have participated in earlier phases. Your physician can check current Canadian site availability through Health Canada's clinical trials database.

Limitations and open questions

The trial data reported by Reuters has not yet appeared in a peer-reviewed journal. The patient population, trial duration, dropout rates, and adverse event profile are not fully described in the available reporting. GLP-1-class drugs share a side-effect profile that includes nausea, vomiting, and gastrointestinal discomfort, and the glucagon receptor component in retatrutide may introduce additional effects not yet fully characterized.

Long-term cardiovascular outcome data for retatrutide do not yet exist. Semaglutide's cardiovascular benefit in people with established heart disease was demonstrated in the SUSTAIN-6 and SELECT trials. No equivalent data exist for retatrutide as of October 2026.

Health Canada has not issued any guidance on retatrutide, and the SOGC has not weighed in. Whether provincial pharmacare plans would cover a triple agonist for obesity, if and when it receives a Notice of Compliance, is entirely unknown. The coverage battles over Wegovy suggest the path will not be straightforward.

The 24 percent weight-loss figure, if it holds, is clinically meaningful. But a drug that works better in a trial is only useful to Canadian patients if it clears Health Canada review, gets listed on provincial formularies at an accessible price, and is prescribed by a physician who has the time and training to monitor its use. None of those conditions are currently met for retatrutide in Canada.

This article is for informational purposes only and is not medical advice. Consult your Canadian healthcare provider about your situation.

Editorial note

Hormone Journal articles are written by our editorial team and reviewed against published clinical guidelines, with a focus on Canadian patient access. We do not promote specific clinics or providers.