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Retatrutide Research Study: A Denominator-First Trial Reading
A denominator-first reading of the retatrutide phase 2 trial, tying each percentage to its population, timepoint, arm, endpoint, comparator, and registration record.
Research or raw-material evaluation only. Not for human or veterinary use.
Retatrutide research study results are percentages only when their denominator, timepoint, dose arm, analysis set, and comparator remain attached. The phase 2 paper (PMID 37366315) enrolled 338 adults, while ClinicalTrials.gov registration NCT04881760 records the same trial’s planned endpoint framework. This page reads the results by those anchors rather than treating a percentage as a stand-alone product claim.
One trial, two result horizons
The primary horizon was baseline to week 24. The registered primary outcome is mean percentage change in body weight at week 24, and the paper reports least-squares mean percentage changes for each retatrutide arm and placebo. The secondary horizon was baseline to week 48, with additional registered threshold outcomes: the percentage of participants achieving at least 5%, 10%, or 15% weight reduction. Safety was assessed across the study period, with heart-rate observations reported by time.
Baseline → randomisation and first once-weekly subcutaneous dose
Week 24 → primary bodyweight percentage endpoint; heart-rate increase reached its reported peak
Week 48 → secondary bodyweight percentage endpoint and 5%/10%/15% threshold outcomes
Population and allocation anchors
Adults were eligible with a body-mass index (BMI) of at least 30 kg/m², or BMI 27 to less than 30 kg/m² with at least one weight-related condition. The double-blind, randomised, placebo-controlled phase 2 trial assigned participants in a 2:1:1:1:1:2:2 ratio to placebo or six retatrutide schedules: 1 mg; 4 mg with a 2 mg initial dose; 4 mg with a 4 mg initial dose; 8 mg with a 2 mg initial dose; 8 mg with a 4 mg initial dose; and 12 mg with a 2 mg initial dose. All were once-weekly subcutaneous injections for 48 weeks. These population and allocation details are reported in PMID 37366315 and can be cross-checked against NCT04881760.
Week-24 denominator and result ledger
| Arm grouping reported in the paper | Least-squares mean change from baseline at week 24 | Comparator and context |
|---|---|---|
| Retatrutide 1 mg | -7.2% | Placebo -1.6%; primary endpoint timepoint |
| Combined retatrutide 4 mg groups | -12.9% | Placebo -1.6%; combined starting-dose schedules |
| Combined retatrutide 8 mg groups | -17.3% | Placebo -1.6%; combined starting-dose schedules |
| Retatrutide 12 mg group | -17.5% | Placebo -1.6%; 2 mg initial dose schedule |
These are least-squares means reported for the phase 2 analysis at week 24. The combined 4 mg and 8 mg rows should not be read as if their distinct starting-dose schedules were a single intervention. The paper’s result is tied to its prespecified analysis and trial population.
Week-48 denominator and threshold ledger
| Arm grouping | Mean percentage change at week 48 | ≥5% / ≥10% / ≥15% reduction at week 48 |
|---|---|---|
| Retatrutide 1 mg | -8.7% | Not stated in the cited abstract for this row |
| Combined retatrutide 4 mg groups | -17.1% | 92% / 75% / 60% |
| Combined retatrutide 8 mg groups | -22.8% | 100% / 91% / 75% |
| Retatrutide 12 mg group | -24.2% | 100% / 93% / 83% |
| Placebo | -2.1% | 27% / 9% / 2% |
The threshold percentages use the participants in the corresponding trial arms as their denominators; the abstract does not provide arm counts for each threshold row. The 4 mg and 8 mg entries are combined groups as reported, while the placebo figures are the placebo group. No unreported denominator or missing 1 mg threshold value is inferred here.
Safety and heart-rate timepoints
The most common adverse events were gastrointestinal, dose-related, and mostly mild to moderate; the paper notes that a lower starting dose of 2 mg partly mitigated these events compared with a 4 mg starting dose. The abstract also reports dose-dependent increases in heart rate that peaked at week 24 and declined thereafter. These are observations from the registered trial and its safety analysis, not a general safety guarantee.
Registration cross-check: what can be matched
NCT04881760 identifies the study as a completed, randomised, parallel phase 2 intervention with 338 actual participants. Its primary outcome is mean percent change from baseline in body weight at week 24. Registered secondary outcomes include mean percent change at week 48 and the 5%, 10%, and 15% threshold outcomes at weeks 24 and 48. The registry helps verify the endpoint names and timeframes; it does not replace the paper’s reported estimates, adverse-event narrative, or statistical context. ClinicalTrials.gov: NCT04881760.
An estimand check also matters. The week 24 estimate is a least-squares mean comparison, while the threshold rows at week 48 are responder proportions. Those are different measures and cannot be combined into one percentage. The registry records planned outcome definitions, but a registry entry does not verify that every planned analysis was completed exactly as written. The publication is the source for the reported estimates and safety narrative; the registry is a cross-check for names, timepoints, and study design. The abstract does not expose every arm count, confidence interval, missing-data rule, or multiplicity adjustment in the compact table above. Those omissions limit any attempt to recalculate the findings from this page. Readers should treat the numbers as a bounded summary of one trial record, not as a forecast for another material, lot, population, or setting.
What this record does not establish
- It does not establish that a supplied research material is the material used in the trial.
- It does not turn study doses, injection routes, or percentages into human-use instructions or treatment guidance.
- It does not provide unreported arm denominators or imply that combined starting-dose groups are identical.
- It does not establish long-term outcomes beyond the 48-week report or the registry’s recorded follow-up.
Boundary to adjacent site pages
The public Retatrutide Research Context and Documentation Boundaries page provides general research-context and record-separation background. This article is narrower: it is a denominator-first reading of one registered phase 2 trial’s timepoints, endpoints, and reported results. It is not the triple-receptor mechanism record, a batch-documentation page, or a product-effect page.
References
- Jastreboff AM et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity – A Phase 2 Trial. N Engl J Med. 2023;389(6):514-526. PMID 37366315. DOI: 10.1056/NEJMoa2301972. Retrieved August 28, 2026.
- ClinicalTrials.gov registration NCT04881760, A Study of LY3437943 in Participants Who Have Obesity or Are Overweight. Retrieved August 28, 2026.
Research scope: This summary reports study details from the cited source and does not provide medical, veterinary, dosing, administration, safety, or treatment guidance. It does not represent a product-use recommendation.
References
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