TRANSCEND-T2D-2: the head-to-head trial
1,298 adults with type 2 diabetes were randomly assigned to retatrutide 9 mg, retatrutide 12 mg or semaglutide 2 mg (the highest Ozempic dose), open-label, for 80 weeks. Lilly reported these topline results in October 2026:[1]
| Retatrutide 9 mg | Retatrutide 12 mg | Semaglutide 2 mg | |
|---|---|---|---|
| Weight change | −19.5% | −20.9% | −9.4% |
| HbA1c change | −2.2% | −2.2% | −1.8% |
| Stopped due to side effects | 4.8% | 7.9% | 2.7% |
| Dysesthesia | 4.8% | 6.5% | 2.7% |
These are topline figures. The full journal paper had not been published as of November 2026.
Retatrutide vs Ozempic: blood sugar
For blood sugar, the gap was smaller than for weight. In TRANSCEND-T2D-2, HbA1c fell by 2.2 percentage points on both retatrutide doses and by 1.8 points on semaglutide 2 mg, the top Ozempic dose.[1] Weight loss, by contrast, was more than twice as large on retatrutide. Lilly reported these as efficacy-estimand figures, which count people who stayed on their assigned drug.[1]
Retatrutide vs Wegovy: weight loss in obesity
There is no head-to-head trial of retatrutide against semaglutide 2.4 mg (Wegovy) in obesity. The closest numbers come from two separate trials, both analyzed by the treatment-regimen method that counts everyone who was randomized:
| Retatrutide 12 mg (TRIUMPH-1) | Semaglutide 2.4 mg (STEP 1) | |
|---|---|---|
| Average weight change | −25.0% | −14.9% |
| Placebo in the same trial | −3.9% | −2.4% |
| Trial length | 80 weeks | 68 weeks |
| Participants | 2,339 | 1,961 |
Sources: TRIUMPH-1[3] and STEP 1.[2] The trials differ in length, populations and years, so the difference between them is only a rough guide.
Who was in the head-to-head trial
TRANSCEND-T2D-2 enrolled adults with type 2 diabetes, not people with obesity alone, and it was open-label, meaning participants knew which drug they were taking. Semaglutide was used at 2 mg, the highest dose approved for diabetes (Ozempic). The weight-loss dose of semaglutide (Wegovy) is 2.4 mg, so this trial does not compare the two drugs at their obesity doses.[1]
Side effects compared
More people stopped retatrutide than semaglutide because of side effects: 4.8% on 9 mg and 7.9% on 12 mg, against 2.7% on semaglutide. Dysesthesia, a skin burning or tingling sensation, was reported in 4.8% and 6.5% on retatrutide against 2.7% on semaglutide.[1] In STEP 1, 4.5% of people on semaglutide 2.4 mg stopped because of stomach side effects, against 0.8% on placebo.[2] The full retatrutide data are on the side effects page.
Doses compared
| Retatrutide | Semaglutide | |
|---|---|---|
| Starting dose in phase 3 | 2 mg | Not compared in these sources |
| Maintenance doses in these trials | 4, 9 and 12 mg (TRIUMPH-1) | 2 mg (TRANSCEND-T2D-2), 2.4 mg (STEP 1) |
| Frequency | Once weekly | Once weekly (injection) |
Sources: TRIUMPH-1,[3] TRANSCEND-T2D-2[1] and STEP 1.[2] The full retatrutide schedule is in the retatrutide dosage chart.
How they differ
| Retatrutide | Semaglutide | |
|---|---|---|
| Receptors | GIP, GLP-1, glucagon | GLP-1 |
| Status | Investigational | FDA-approved (Ozempic, Wegovy, Rybelsus) |
| Dosing | Once weekly injection | Weekly injection or daily tablet |
Related
Frequently asked questions
Is retatrutide stronger than Ozempic?
In TRANSCEND-T2D-2, weight loss on retatrutide 12 mg was −20.9% against −9.4% on semaglutide 2 mg at 80 weeks (Lilly topline figures).[1]
Is retatrutide better than Wegovy for weight loss?
Did more people stop retatrutide than semaglutide?
Yes. In TRANSCEND-T2D-2, 4.8% (9 mg) and 7.9% (12 mg) stopped retatrutide because of side effects, against 2.7% on semaglutide.[1]
Can I switch from semaglutide to retatrutide?
Not outside a clinical trial or an approved expanded-access request, because retatrutide is not approved. See how to get retatrutide.