Retatrutide produced more than twice the average weight loss of Ozempic in a Phase 3 clinical trial involving adults with type 2 diabetes. The results also showed greater improvements in blood sugar control. However, treatment discontinuations due to adverse events were higher with retatrutide.

On 28 October 2026, Eli Lilly announced results from TRANSCEND-T2D-2, a Phase 3 trial directly comparing retatrutide with Ozempic (semaglutide).

After 80 weeks, participants receiving retatrutide 12 mg lost an average of 20.9% of their body weight. Those receiving Ozempic 2 mg lost 9.4%.

These findings provide important evidence for the retatrutide vs Ozempic comparison. However, the results require context, particularly regarding treatment doses, trial design, side effects and the limitations of company-reported data.

This article is part of our ⁠R10 Research Notes collection. It examines the reported clinical findings, explains what the comparison establishes and identifies the questions that remain unanswered.

What Is the Difference Between Retatrutide and Ozempic?

Retatrutide and Ozempic both act on hormone receptors involved in blood sugar regulation and metabolism. However, they work through different receptor pathways.

Ozempic contains semaglutide, a glucagon-like peptide-1 (GLP-1) receptor agonist. It mimics GLP-1 activity, influencing insulin secretion, appetite regulation and gastric emptying.

Retatrutide is an investigational triple hormone receptor agonist. It activates three receptors:

• GLP-1, involved in glucose regulation, appetite and gastric emptying.
• GIP, involved in glucose-dependent insulin secretion and metabolic signalling.
• Glucagon, involved in energy metabolism and glucose regulation.

This triple-receptor activity distinguishes retatrutide from semaglutide.

However, activating more receptors does not automatically establish that one medication is more effective or safer than another. Researchers need controlled clinical trials to assess those differences.

Our separate article on ⁠what retatrutide does explains its mechanism and the scientific evidence behind its development.

What Did the Retatrutide vs Ozempic Clinical Trial Find?

On 28 October 2026, Eli Lilly reported results from TRANSCEND-T2D-2, a randomised, open-label Phase 3 clinical trial.

The study enrolled 1,298 adults with type 2 diabetes. Their blood sugar levels were inadequately controlled with metformin, with or without an SGLT2 inhibitor.

Researchers compared three once-weekly treatment groups:

• Retatrutide 9 mg
• Retatrutide 12 mg
• Ozempic (semaglutide) 2 mg

The primary endpoint assessed changes in HbA1c, a measure of average blood glucose over approximately two to three months. Body-weight change was a key secondary endpoint.

Researchers assessed outcomes after 80 weeks.

The ⁠TRANSCEND-T2D-2 trial registration documents the study design, eligibility criteria and planned outcomes.

Retatrutide vs Ozempic: Clinical Trial Results

The following table summarises the efficacy results Lilly reported on 28 October 2026.

Source: Eli Lilly, TRANSCEND-T2D-2 topline announcement, 28 October 2026. Weight-loss and HbA1c results use the efficacy estimand. The discontinuation row shows reported adverse-event discontinuation rates.

Lilly reported statistically significant improvements in body-weight reduction with both retatrutide doses compared with Ozempic 2 mg.

The trial also reported greater average HbA1c reductions with retatrutide.

Importantly, researchers compared the treatments within the same clinical trial. This provides more direct comparative evidence than examining results from separate studies with different populations and treatment conditions.

At the time of Lilly’s October 2026 announcement, the detailed findings had not been published in a peer-reviewed journal.

Therefore, these figures represent company-reported topline evidence rather than a complete independently reviewed publication.

Does Retatrutide Really Deliver Double the Weight Loss of Ozempic?

Yes. In TRANSCEND-T2D-2, both retatrutide doses produced more than twice the average percentage weight reduction reported with Ozempic 2 mg.

Participants receiving retatrutide 12 mg lost an average of 20.9% of their starting body weight. By comparison, the Ozempic group lost 9.4%.

That represents approximately 2.2 times the average percentage weight reduction.

The difference between the two results was 11.5 percentage points.

These figures describe the same comparison in different ways. The 2.2-times figure expresses the relative difference, while 11.5 percentage points expresses the difference between the reported percentages.

Lilly’s ⁠October 2026 trial announcement provides the original results and statistical comparisons.

However, the headline requires several qualifications.

The study involved adults with type 2 diabetes. It compared specific retatrutide doses with Ozempic 2 mg, not every semaglutide formulation or dose.

The reported weight-loss figures also used an efficacy estimand.

This estimates treatment effects under a hypothetical scenario in which all randomised participants remained on study treatment for 80 weeks. The analysis allowed possible dose interruptions and modifications but excluded starting additional glucose-lowering medication for more than 14 days.

Consequently, these figures should not be interpreted as the average outcome every person starting treatment can expect.

Our separate article on ⁠retatrutide weight loss examines the wider Phase 2 and Phase 3 evidence. It also explains why different studies report different weight-loss percentages.

How Did Retatrutide and Ozempic Compare for Blood Sugar Control?

TRANSCEND-T2D-2 primarily investigated blood sugar control in adults with type 2 diabetes.

Researchers measured changes in HbA1c after 80 weeks.

Lilly reported average HbA1c reductions of:

• 2.2 percentage points with retatrutide 9 mg.
• 2.2 percentage points with retatrutide 12 mg.
• 1.8 percentage points with Ozempic 2 mg.

The average starting HbA1c was 8.3%.

Both retatrutide groups achieved greater average reductions than the Ozempic group.

The trial’s primary endpoint tested whether retatrutide 12 mg was noninferior to Ozempic 2 mg for HbA1c reduction.

Lilly reported that the trial met this endpoint. The company also reported statistically significant superiority for retatrutide 12 mg, with adjustments for multiple comparisons.

Retatrutide 9 mg also showed a greater HbA1c reduction than Ozempic 2 mg. However, Lilly reported nominal statistical significance for this superiority comparison rather than multiplicity-controlled significance.

This distinction matters because the statistical evidence for the two comparisons was assessed differently.

Lilly additionally reported improvements in selected cardiovascular risk factors, including non-HDL cholesterol, triglycerides and systolic blood pressure.

However, improvements in these measurements do not establish a reduction in cardiovascular events such as heart attacks or strokes.

The trial establishes comparative outcomes under its study conditions. It does not isolate how much each receptor pathway contributed to those differences.

How Did Retatrutide and Ozempic Side Effects Compare?

Greater average weight reduction does not necessarily mean a treatment has a better overall safety profile.

TRANSCEND-T2D-2 reported gastrointestinal adverse events across all three treatment groups.

Reported Adverse Events

Source: Eli Lilly, TRANSCEND-T2D-2 topline announcement, 28 October 2026. Percentages represent the reported incidence of each adverse event.

Diarrhoea occurred more frequently in both retatrutide groups than in the Ozempic group.

Nausea rates were relatively similar, while vomiting was more frequent with retatrutide 12 mg.

Constipation was more frequently reported with Ozempic.

Dysesthesia, which refers to abnormal or unpleasant sensations, occurred more frequently in the retatrutide groups.

Treatment Discontinuations

Adverse-event discontinuation rates were 4.8% with retatrutide 9 mg, 7.9% with retatrutide 12 mg and 2.7% with Ozempic 2 mg.

These findings matter when interpreting the weight-loss results.

Although retatrutide produced greater average weight reduction, a higher proportion of participants stopped treatment because of adverse events.

Therefore, the reported findings do not establish that retatrutide has a better overall safety profile than Ozempic.

For further context, see our research on ⁠retatrutide side effects and ⁠whether retatrutide is safe.

Retatrutide vs Wegovy: What Is the Difference?

Retatrutide vs Wegovy is another important comparison, although the two medications were not directly compared in TRANSCEND-T2D-2.

Wegovy contains semaglutide, the same active ingredient found in Ozempic. However, the two products have different approved indications and dosing regimens.

Retatrutide is a separate investigational molecule that activates GLP-1, GIP and glucagon receptors.

The October 2026 trial compared retatrutide with Ozempic 2 mg, not Wegovy’s weight-management dosing regimen.

Consequently, the findings do not establish that retatrutide produces twice the weight loss of Wegovy.

What Are the Limitations of the Retatrutide vs Ozempic Evidence?

The October 2026 findings provide valuable comparative evidence. However, several limitations deserve attention.

Company-reported results. Lilly released topline findings in October 2026 rather than a complete peer-reviewed paper. Therefore, detailed methods and additional analyses were not fully available for independent assessment at that time.

Open-label trial design. Participants and investigators knew which treatment participants received. This can influence some aspects of trial conduct and reporting, particularly subjective outcomes.

Specific study population. Participants had type 2 diabetes and met the study’s eligibility criteria. The findings may not apply equally to people without diabetes or those with different medical circumstances.

Specific doses. The trial compared retatrutide 9 mg and 12 mg with Ozempic 2 mg. Researchers cannot automatically extend these findings to other doses without supporting evidence.

Limited long-term conclusions. The reported comparison covered 80 weeks. It does not establish outcomes over many years or what happens after treatment stops.

Incomplete long-term safety evidence. Larger datasets and longer follow-up are important for identifying uncommon adverse events and understanding long-term risks.

These limitations do not invalidate the reported results. Instead, they define what the evidence can reasonably support.

Is Retatrutide Approved in Australia?

As of November 2026, retatrutide had not received approval from Australia’s Therapeutic Goods Administration (TGA) for weight management or type 2 diabetes treatment.

The October 2026 TRANSCEND-T2D-2 announcement did not change its regulatory status.

Clinical trial results and regulatory approval are separate matters.

Even when a trial reports statistically significant outcomes, regulators must assess the broader evidence for quality, safety and efficacy before authorising a medicine for clinical use.

In a ⁠September 2026 safety alert, the TGA reported testing a counterfeit product sold as retatrutide. The tested product contained undeclared semaglutide rather than retatrutide.

That finding concerned a specific tested product and should not be generalised to every product marketed under the same name.

However, the TGA warned that products sold as retatrutide outside clinical trials may be counterfeit and could pose serious health risks.

Our article on ⁠whether retatrutide is available in Australia explains the distinction between clinical development, regulatory approval and research supply.

For broader research information and supporting documentation, visit ⁠Retatrutide Australia.

Key Takeaways

• Retatrutide 9 mg and 12 mg produced more than twice the average percentage weight reduction reported with Ozempic 2 mg after 80 weeks.
• Retatrutide also achieved greater average HbA1c reductions in adults with type 2 diabetes.
• Gastrointestinal adverse events occurred across all three treatment groups.
• Adverse-event discontinuations were more frequent with retatrutide, particularly at 12 mg.
• The findings apply to the studied population, treatment doses and trial conditions.
• At the time of Lilly’s October 2026 announcement, the detailed results had not been published in a peer-reviewed journal.

Frequently Asked Questions

Does Retatrutide Cause Twice as Much Weight Loss as Ozempic?

In TRANSCEND-T2D-2, retatrutide 12 mg produced an average body-weight reduction of 20.9%, compared with 9.4% for Ozempic 2 mg after 80 weeks.

That represents approximately 2.2 times the average percentage weight reduction under the study conditions.

Is Retatrutide Stronger Than Semaglutide?

Retatrutide activates three hormone receptors, while semaglutide activates the GLP-1 receptor.

The October 2026 trial reported greater average weight reduction and HbA1c improvements with retatrutide than with semaglutide 2 mg.

However, the term “stronger” does not adequately describe every aspect of efficacy, safety or tolerability.

Has Retatrutide Been Compared Directly With Ozempic?

Yes. TRANSCEND-T2D-2 was a randomised Phase 3 trial comparing retatrutide 9 mg and 12 mg directly with Ozempic 2 mg.

Eli Lilly announced the topline results on 28 October 2026.

Is Reta the Same as Retatrutide?

Yes. Reta is an informal abbreviation commonly used when discussing retatrutide.

It refers to the same investigational triple hormone receptor agonist.

Our article explaining ⁠what is reta peptide provides further background.

Research Sources

1. Eli Lilly and Company. Lilly’s retatrutide delivered ⁠greater A1C reduction and more than double the weight loss of Ozempic’s highest approved dose in head-to-head trial. Published 28 October 2026.
2. ClinicalTrials.gov. Effect of Retatrutide ⁠Compared With Semaglutide in Adult Participants With Type 2 Diabetes and Inadequate Glycemic Control With Metformin With or Without SGLT2 Inhibitor (TRANSCEND-T2D-2). Clinical trial registration NCT06260722.
3. Therapeutic Goods Administration. TGA Tests ⁠Counterfeit Retatrutide Product Following Serious Adverse Event Report. Published 14 September 2026.