Retatrutide vs Ozempic: What Lilly's Head-to-Head Trial Showed (October 2026)

Last updated: October 28, 2026.

Short answer: In Eli Lilly's TRANSCEND-T2D-2 trial, announced on October 28, 2026, retatrutide lowered A1C by 2.2 points against 1.8 for the highest dose of Ozempic (semaglutide), and body weight fell 19.5% to 20.9% against 9.4%, more than double. Retatrutide is still investigational: it is not approved by Health Canada or the US FDA.

Key facts

• Retatrutide vs Ozempic: in adults with type 2 diabetes over 80 weeks, A1C fell 2.2 points on retatrutide and 1.8 points on semaglutide, and body weight fell 19.5% to 20.9% against 9.4% (Eli Lilly, October 28, 2026).
• Sleep apnea: in two phase 3 trials published in the New England Journal of Medicine on October 23, 2026, breathing interruptions during sleep fell by 34.3 and 31.7 events an hour on retatrutide against 9.9 on placebo in adults without diabetes.
• Kidneys: in a 24-week phase 2b trial, protein in the urine fell 53.7% on retatrutide against 8.8% on placebo.
• Approval: retatrutide is not approved by Health Canada or the US FDA, and Lilly has not filed for approval yet.
• Canada: Kits Peptides, a supplier in Vancouver, sells retatrutide as a laboratory research reagent and is keeping its prices where they are.

Retatrutide vs Ozempic at a glance

What Lilly announced on October 28

TRANSCEND-T2D-2 put two doses of retatrutide against the highest dose of semaglutide, the drug in Ozempic, for 80 weeks in adults with type 2 diabetes.

• Blood sugar: A1C fell 2.2 points on both retatrutide doses, against 1.8 on semaglutide. The higher dose was statistically better than semaglutide on the trial's main measure.
• Body weight: down 19.5% to 20.9% on retatrutide, against 9.4% on semaglutide.
• Heart markers: non-HDL cholesterol, triglycerides and systolic blood pressure also improved more on retatrutide. Lilly did not give the size of those gaps.
• Side effects: more people stopped retatrutide because of side effects, 4.8% and 7.9% on the two doses. Most were mild to moderate.

These are topline figures from Lilly. The full peer-reviewed paper is not out yet.

Retatrutide and sleep apnea

On October 23, 2026, the New England Journal of Medicine published two phase 3 trials, TRIUMPH-1-OSA and TRIUMPH-2-OSA, in adults with moderate to severe obstructive sleep apnea. Both tracked the apnea-hypopnea index (AHI), the number of times an hour breathing stops or becomes shallow during sleep, over 80 weeks.

• Without type 2 diabetes (243 adults): AHI fell 34.3 and 31.7 events an hour on the two higher doses, against 9.9 on placebo.
• With type 2 diabetes (448 adults): AHI fell 24.7 and 25.4 events an hour, against 10.3 on placebo.
• Gastrointestinal side effects were the most common.

Retatrutide and the kidneys

TRANSCEND-CKD, a 24-week phase 2b trial in adults with obesity or overweight and chronic kidney disease, ran at 42 sites, some of them in Canada. In participants who started with raised urine protein, the urine albumin-to-creatinine ratio fell 53.7% on retatrutide against 8.8% on placebo. Measured kidney filtration did not change.

Where it started: TRIUMPH-1

In May 2026 Lilly reported TRIUMPH-1, an 80-week phase 3 trial in 2,339 adults with obesity or overweight and no diabetes. Average body weight fell 28.3% on the highest dose against 2.2% on placebo, and 45.3% of that group lost 30% or more.

What the FDA compounding news means, and what it does not

Separately, the US FDA is preparing a policy that would let American compounding pharmacies make some peptides on prescription. The White House finished reviewing it on October 27, 2026, and the FDA has not published it yet. The FDA's advisers reviewed BPC-157, TB-500, KPV, MOTS-c, Epitalon and Semax; retatrutide was not on that list. More in what the FDA policy means for BPC-157 in Canada.

In the US, a compounded peptide comes with a prescription and a pharmacy's margin on top. Canada is not covered by the policy, and Health Canada's position has not changed.

Kits Peptides is keeping its prices where they are. Retatrutide 10mg is CA$64.99, BPC-157 10mg is CA$49.99 and TB-500 5mg is CA$47.99. Our current retatrutide 10mg lot, KP-RETA10-L1, was tested by SideChain Analytics, a Canadian lab, at 99.8% purity on a certificate issued to Kits Peptides.

Is retatrutide better than Ozempic?

In TRANSCEND-T2D-2 it lowered A1C and body weight more than the highest dose of Ozempic: 2.2 against 1.8 A1C points, and 19.5% to 20.9% against 9.4% of body weight. That is one trial in adults with type 2 diabetes, announced by Lilly before peer review.

Is retatrutide approved in Canada?

No. Retatrutide is not approved by Health Canada, has no DIN, and is not approved by the US FDA either.

When could retatrutide be approved?

Lilly has not filed for approval yet. Industry trackers expect its first filing in 2027.

What is retatrutide?

A synthetic peptide that acts on three receptors: GLP-1, GIP and glucagon. Semaglutide (Ozempic) acts on one, GLP-1, and tirzepatide (Mounjaro) on two. That third receptor is the main difference. More in our retatrutide research primer and retatrutide vs semaglutide.

Will retatrutide get more expensive?

Not at Kits Peptides. We are keeping our prices where they are: retatrutide 10mg is CA$64.99.

Where can I buy retatrutide in Canada?

Kits Peptides, in Kitsilano, Vancouver, supplies retatrutide as a laboratory reagent for research use only, not for human or veterinary use. Orders ship tracked across Canada and same day in Metro Vancouver. See buying retatrutide in Canada.

Sources

• Retatrutide tops semaglutide on A1C and weight in head-to-head trial (AJMC)
• TRANSCEND-T2D-2 (HCPLive)
• Retatrutide and obstructive sleep apnea (New England Journal of Medicine)
• Retatrutide lowers albuminuria in obesity and CKD (HCPLive)
• TRIUMPH-1 announcement (Eli Lilly)
• Retatrutide phase 3 tracker (Compound Review)
• FDA interim peptide compounding policy (Buchanan Ingersoll & Rooney)