Disclosed LabsRetatrutide Before & After
Published weight loss data from the Phase 2 TRIUMPH trial of retatrutide (LY3437943). Week-by-week timeline, dose-response curve, body composition changes, and how the results compare to tirzepatide and semaglutide.
Trial data, not personal results
The data on this page comes from published clinical trial results, not individual user reports. Retatrutide is in Phase 3 trials in 2026 and is not FDA-approved. This page is research-context only — Disclosed Labs publishes vendor and lab transparency data and does not provide medical advice or dosing recommendations.
Phase 2 TRIUMPH trial: mean weight loss by dose
Source: Jastreboff AM, Kaplan LM, Frias JP, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity — A Phase 2 Trial. N Engl J Med 2023 (PubMed 37366315). 338 adults enrolled, 48-week follow-up. Numbers below are the published mean percent change in body weight at 48 weeks.
| Dose arm | Mean body weight change | Participants ≥ 15% loss |
|---|---|---|
| Placebo | −2.1% | 2% |
| 1 mg | −8.7% | not reported |
| 4 mg (combined arms) | −17.1% | 60% |
| 8 mg (combined arms) | −22.8% | 75% |
| 12 mg | −24.2% | 83% |
Note: the published trial design included multiple titration arms (e.g. 4 mg starting / 4 mg maintenance, 4 mg starting / 8 mg maintenance, 2 mg starting / 12 mg maintenance). Numbers above collapse the arms by max maintenance dose. For the exact arm structure and full statistics, see the source publication.
Timeline notes
The TRIUMPH trial used a titration schedule starting at 2 mg weekly and stepping up at 4-week intervals to manage gastrointestinal tolerability. Per the published curve, weight loss continued descending through the 48-week endpoint at the higher dose arms — meaning a terminal plateau had not yet been characterized.
Specific week-by-week milestone percentages are not extracted here because the published paper reports interim measurements at specific timepoints rather than a continuous curve we can transcribe accurately. Refer to the source publication for the full longitudinal plot.
Compared to other GLP-1 agonists
Cross-trial comparisons are imperfect — different study designs, durations, populations, and analysis methods. The figures below are widely-cited published anchor points, but no direct head-to-head trial has been completed. Read these as ballpark references, not equivalence.
| Drug | Trial | Mean change | Duration |
|---|---|---|---|
| Retatrutide 12 mg | TRIUMPH Ph2 | −24.2% | 48 wk |
| Tirzepatide 15 mg | SURMOUNT-1 | ≈ −20.9% | 72 wk |
| Semaglutide 2.4 mg | STEP-1 | ≈ −14.9% | 68 wk |
Confirm any specific number against the source paper before citing it. The values above are pulled from commonly-referenced primary-study results but trial endpoints sometimes vary slightly between primary publication and follow-up extension reports.
Related retatrutide guides
TRIUMPH titration schedule (2mg → 12mg over 16 weeks) and reconstitution math.
Where research-grade retatrutide comes from while Phase 3 runs. Vendor quality framework + COA red flags.
Mechanism, references, dosing context.
Side-by-side comparison of mechanism, dosing, and trial results.
Frequently asked questions
How much weight do people lose on retatrutide?
In the Phase 2 TRIUMPH trial (Jastreboff et al., NEJM 2023), 338 adults were randomized across dose arms. Mean percent change in body weight at 48 weeks: 1 mg arm −8.7%, combined 4 mg arms −17.1%, combined 8 mg arms −22.8%, 12 mg arm −24.2%. Placebo arm −2.1%. The 12 mg arm produced the largest mean weight reduction reported in any published Phase 2 obesity trial to date.
What percentage of participants reached ≥15% weight loss?
Per the published TRIUMPH results: 60% of participants on the combined 4 mg arms, 75% on the combined 8 mg arms, and 83% on the 12 mg arm achieved at least 15% weight loss at 48 weeks. Placebo was 2%. Individual variation within each arm was substantial.
How long was the trial?
48 weeks. The published weight-loss curve was still descending at the trial endpoint, meaning peak loss had not yet been observed. Phase 3 trials (TRIUMPH-1, TRIUMPH-2, TRIUMPH-4) use longer follow-up windows to characterize the terminal plateau and durability of effect.
How does retatrutide compare to other GLP-1 agonists?
Cross-trial comparisons are imperfect (different study designs, durations, and populations). The published anchor data points: retatrutide 12 mg produced −24.2% mean loss at 48 weeks (TRIUMPH Phase 2). Tirzepatide 15 mg produced approximately −20.9% to −22.5% at 72 weeks across SURMOUNT-1 analyses. Semaglutide 2.4 mg produced approximately −14.9% at 68 weeks in STEP-1. Direct head-to-head comparison data is not yet published.
What body composition changes happen?
The TRIUMPH publication documented reductions in fat mass with relative preservation of lean mass across the active dose arms. Specific fat-to-lean loss ratios were reported in the published supplement. Reductions in hepatic steatosis (fatty liver) and abdominal visceral adipose tissue were also observed. Body-composition outcomes appear comparable to other incretin therapies and depend in practice on dietary protein intake and resistance training.
When do side effects show up?
Gastrointestinal side effects — nausea, vomiting, diarrhea, constipation — were most common during dose escalation, similar to the pattern with tirzepatide and semaglutide. The TRIUMPH trial reported that gastrointestinal events were mostly mild to moderate. Specific discontinuation rates per arm are reported in the published paper; refer to the source for exact numbers.
Are the published before-and-after images representative?
Published before-and-after photographs from clinical trials are typically illustrative rather than representative of the mean response. The trial mean at the 12 mg dose was −24.2% at 48 weeks; individual outcomes varied substantially around that mean. Any single set of images should be read as one data point, not the expected outcome for any individual.