Trial comparison table
Metabolic peptide trial comparison table
Side-by-side static table of pivotal metabolic peptide trials: phase, population, comparator, duration, primary endpoint, evidence grade, key safety summary and UK relevance. No statistics are invented — exact numerical results require the cited publication.
This table presents the 13 pivotal metabolic peptide trials side-by-side — phase, population, comparator, duration, primary endpoint and evidence grade. Semaglutide and tirzepatide have the most trials, including cardiovascular outcome trials (SELECT, SURPASS-CVOT, SUMMIT); retatrutide remains in phase 3 without a completed outcome trial. Numerical results are not duplicated here — exact figures require the cited publications. Cross-trial comparison has limits — see the linked research-methods primer.
| Trial | Molecule | Phase | Population | Comparator | Duration | Primary endpoint | Evidence grade |
|---|---|---|---|---|---|---|---|
| SURMOUNT-1 | Tirzepatide (Mounjaro / Zepbound) | Phase 3 | Adults with overweight or obesity (BMI ≥30, or ≥27 with weight-related comorbidities) without type 2 diabetes. ≈2,500 participants. | Placebo (matching saline subcutaneous injection) | 72 weeks | Percent change in body weight from baseline at week 72; proportion achieving ≥5% body-weight reduction. | Evidence: Phase 3 |
| SURMOUNT-2 | Tirzepatide (Mounjaro / Zepbound) | Phase 3 | Adults with type 2 diabetes and obesity (BMI ≥27). ≈900 participants. | Placebo | 72 weeks | Percent change in body weight from baseline at week 72. | Evidence: Phase 3 |
| SURMOUNT-3 | Tirzepatide | Phase 3 | Adults with obesity (BMI ≥30) or overweight (BMI ≥27) with a weight-related comorbidity, following an initial 12-week lifestyle lead-in. | Placebo | 72 weeks treatment after lead-in | Additional percent body-weight reduction from randomisation to week 72. | Evidence: Phase 3 |
| SURMOUNT-4 | Tirzepatide | Phase 3 | Adults with obesity or overweight with comorbidities, randomised after a 36-week open-label tirzepatide run-in. | Continuation of tirzepatide vs withdrawal to placebo (randomised withdrawal design). | 88 weeks total (36-week open-label lead-in + 52-week randomised withdrawal). | Percent change in body weight from week 36 (randomisation) to week 88. | Evidence: Phase 3 |
| SURMOUNT-5 | Tirzepatide | Phase 3 | Head-to-head trial in adults with obesity comparing tirzepatide versus semaglutide. | Semaglutide 2.4 mg weekly (Wegovy reference) | 72 weeks | Percent change in body weight from baseline at week 72. | Evidence: Phase 3 |
| SURPASS-2 | Tirzepatide (Mounjaro) | Phase 3 | Adults with type 2 diabetes inadequately controlled on metformin. ≈1,880 participants. | Semaglutide 1.0 mg subcutaneous weekly (active comparator; the licensed glycaemic-control dose for type 2 diabetes). | 40 weeks | Change in HbA1c from baseline at week 40; body-weight change assessed as a key secondary endpoint. | Evidence: Phase 3 |
| SURPASS-CVOT | Tirzepatide (Mounjaro) | Phase 3 CVOT | Adults with type 2 diabetes and established atherosclerotic cardiovascular disease (ASCVD). ≈13,000 participants. | Dulaglutide (active GLP-1 receptor agonist comparator) | Event-driven, multi-year follow-up. | Time to first occurrence of MACE-3 (cardiovascular death, non-fatal myocardial infarction, non-fatal stroke). | Evidence: Outcome trial evidence |
| SELECT | Semaglutide 2.4 mg (Wegovy) | Outcome trial | Adults aged ≥45 years with overweight or obesity (BMI ≥27) and established cardiovascular disease but without type 2 diabetes. ≈17,600 participants. | Placebo (matched subcutaneous injection) | Median follow-up of approximately 39.8 months. | Time to first major adverse cardiovascular event (MACE-3): cardiovascular death, non-fatal myocardial infarction, non-fatal stroke. | Evidence: Outcome trial evidence |
| STEP 1 | Semaglutide 2.4 mg (Wegovy) | Phase 3 | Adults with BMI ≥30, or ≥27 with weight-related comorbidities, without type 2 diabetes. ≈1,961 participants. | Placebo | 68 weeks | Percent change in body weight from baseline at week 68. | Evidence: Phase 3 |
| STEP 2 | Semaglutide 2.4 mg (Wegovy) | Phase 3 | Adults with type 2 diabetes and overweight (BMI ≥27) or obesity (BMI ≥30). ≈1,200 participants. | Placebo and semaglutide 1.0 mg (active, licensed T2D glycaemic-control dose, as a comparator arm). | 68 weeks | Percent change in body weight from baseline at week 68. | Evidence: Phase 3 |
| STEP 5 | Semaglutide 2.4 mg (Wegovy) | Phase 3 | Adults with obesity, randomised to continued semaglutide vs placebo for 104 weeks. | Placebo | 104 weeks (2 years) | Percent change in body weight from baseline at week 104. | Evidence: Phase 3 |
| LEADER | Liraglutide (Victoza) | Outcome trial | Adults with type 2 diabetes at high cardiovascular risk. ≈9,340 participants. | Placebo | Median follow-up 3.8 years. | MACE-3 (cardiovascular death, non-fatal MI, non-fatal stroke). | Evidence: Outcome trial evidence |
| SUSTAIN-6 | Semaglutide (Ozempic) | Outcome trial | Adults with type 2 diabetes at high cardiovascular risk (established cardiovascular disease, heart failure, chronic kidney disease, or age ≥60 with cardiovascular risk factors). ≈3,300 participants. | Placebo | 104 weeks (2 years) of randomised treatment, with a planned observation period thereafter. | Time to first MACE-3 (cardiovascular death, non-fatal myocardial infarction, non-fatal stroke), assessed for non-inferiority against a pre-specified margin. | Evidence: Outcome trial evidence |
| PIONEER 6 | Semaglutide (oral) (Rybelsus) | Outcome trial | Adults with type 2 diabetes at high cardiovascular risk (established cardiovascular disease, chronic kidney disease, or age ≥60 with cardiovascular risk factors). ≈3,180 participants. | Placebo | Median follow-up of approximately 15.9 months — a shorter observation period than most GLP-1 receptor agonist cardiovascular outcome trials. | Time to first MACE-3, assessed for non-inferiority against a pre-specified margin. | Evidence: Outcome trial evidence |
| REWIND | Dulaglutide (Trulicity) | Outcome trial | Adults with type 2 diabetes at high cardiovascular risk, including a substantial primary-prevention subset (approximately 69% without established atherosclerotic CV disease at baseline). ≈9,900 participants across 24 countries. | Placebo | Median follow-up 5.4 years. | MACE-3 (composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke). | Evidence: Outcome trial evidence |
| SCALE Obesity and Prediabetes | Liraglutide 3.0 mg (Saxenda) | Phase 3 | Adults with obesity (BMI ≥30) or overweight (BMI ≥27) with prediabetes or comorbidities. ≈3,731 participants. | Placebo | 56 weeks | Percent change in body weight; proportion achieving ≥5% body-weight reduction. | Evidence: Phase 3 |
| TRIUMPH programme | Retatrutide | Phase 3 | Adults across multiple TRIUMPH studies — obesity, T2D, and MASLD/MASH cohorts. Trials are ongoing or with topline-only data at the time of review. | Placebo (and active comparators in selected studies). | Programme spans multiple multi-year studies. | Varies by individual TRIUMPH study (weight, HbA1c, hepatic outcomes). | Evidence: Phase 3 |
| FLOW | Semaglutide 1.0 mg (Ozempic) | Outcome trial | Adults with type 2 diabetes and chronic kidney disease (CKD). ≈3,500 participants. | Placebo | Trial was stopped early at planned interim analysis for efficacy. | Composite kidney outcome (persistent ≥50% eGFR reduction, kidney failure, kidney or cardiovascular death). | Evidence: Outcome trial evidence |
| SUMMIT | Tirzepatide (Mounjaro / Zepbound) | Phase 3 | Adults with heart failure with preserved ejection fraction (HFpEF) and obesity (BMI ≥30). ≈730 participants. | Placebo | 52 weeks | Co-primary composite of cardiovascular death or worsening heart-failure events; change in Kansas City Cardiomyopathy Questionnaire (KCCQ-CSS) at 52 weeks. | Evidence: Outcome trial evidence |
| SYNERGY-NASH | Tirzepatide (Mounjaro / Zepbound) | Phase 3 | Adults with biopsy-confirmed metabolic dysfunction-associated steatohepatitis (MASH) and stage F2-F3 liver fibrosis. ≈190 participants. | Placebo | 52 weeks | MASH resolution without worsening of liver fibrosis, assessed on paired liver biopsy at 52 weeks. | Evidence: Phase 3 |
For exact numerical results (mean percent body-weight reductions, hazard ratios, MACE event counts, HbA1c deltas) refer to the linked primary publication on each trial page. Numerical claims are not duplicated on this comparison table to avoid version drift.
What this table cannot do
- It cannot establish that any one trial result generalises beyond its studied population.
- Side-by-side rows are not a head-to-head comparison; SURMOUNT-5 and SURPASS-2 are the head-to-head trials.
- Cross-trial inference requires explicit methodology — see how to compare trials without overclaiming.
Last reviewed 20 May 2026 · trial comparison table · Metabolic Peptides editorial team