# Retatrutide Results in the Clinical Trials — Phase 2 Outcomes Data

> Retatrutide results from Phase 2: −24.2% body weight, −82.4% liver fat, −2.02% HbA1c. Endpoint-by-endpoint readout of the published trial record.

Phase 1b through Phase 2a — body weight, HbA1c, liver fat, lipids, and cardiovascular markers. Figures cited to their source.

## Before the numbers: what this page covers

Retatrutide results in the clinical trials are the main data record this site exists to index. The figures below are trial-measured outcomes — what the studies actually reported, in the populations they actually enrolled, at the doses they actually administered. These are not estimates, projections, or extrapolations. The -24.2% body weight at 12 mg/48 wk was measured in 338 adults in a randomized controlled trial published in the *New England Journal of Medicine* [1]. The -82.4% liver fat at 24 weeks was measured via MRI-PDFF in 98 participants in a *Nature Medicine* substudy [5]. Every figure on this page cites its source. What these numbers mean for any individual is a clinical question this site does not answer — but the numbers themselves are real, they are large, and the cardiometabolic signal in them is the reason the TRIUMPH Phase 3 program exists.

## Body weight: the primary efficacy endpoint

**Phase 2 obesity trial (Jastreboff et al., *N Engl J Med*, 2023) — 338 adults, 48 weeks [1]:**

| Dose (once weekly) | Mean body-weight change at 48 wk |
|--------------------|-----------------------------------|
| Placebo | −2.1% |
| 1 mg | −8.7% |
| 4 mg | −17.3% |
| 8 mg | −22.8% |
| 12 mg | −24.2% |

The dose-response is clear and progressive: each step up in dose produced a meaningfully larger weight-loss effect. The 12 mg result — a mean of nearly a quarter of body weight lost over 48 weeks — represents the largest mean weight reduction reported in a Phase 2 anti-obesity pharmacotherapy trial as of the time of publication.

**Phase 2 type 2 diabetes trial (Rosenstock et al., *Lancet*, 2023) — 281 adults, 36 weeks [2]:**

- 12 mg: −16.94% body weight vs −3.00% placebo at 36 weeks [2].

**Phase 1b (Urva et al., *Lancet*, 2022) — 72 adults with T2D, 12 weeks [4]:**

- Highest-dose group: −8.96 kg placebo-adjusted weight loss [4].

A 2024 analysis of once-weekly subcutaneous retatrutide across Phase 2 confirms dose-dependent weight loss with concomitant improvements in glycemia, lipids, and blood pressure [7].

## HbA1c and glucose: cardiometabolic endpoints

**Phase 2 diabetes trial HbA1c results (Rosenstock et al., 2023) [2]:**

| Dose | HbA1c change at 24 wk |
|------|----------------------|
| Placebo | −0.01% |
| 12 mg | −2.02% |

An HbA1c (glycated hemoglobin — a three-month blood-glucose average) reduction of −2.02% is clinically substantial; most approved GLP-1 mono-agonists in T2D produce −1.0 to −1.7% in comparable trials.

**Phase 1b glucose results [4]:**
- Daily mean glucose reduced by −2.8 mmol/L at 3 mg [4].

At the ACC 2024 annual meeting, a post-hoc analysis of the Phase 2 obesity trial reported improvements in lipids and cardiovascular risk factors alongside weight loss, though full peer-reviewed numeric detail remains pending publication [8].

## Liver fat: MASLD substudy results

The Phase 2a MASLD substudy (Sanyal et al., *Nature Medicine*, 2024) enrolled 98 participants with obesity and ≥10% liver fat by MRI-PDFF (a non-invasive measurement of liver fat using magnetic resonance imaging) [5].

**Relative liver-fat change at 24 weeks:**

| Dose | Relative liver-fat change |
|------|---------------------------|
| Placebo | +0.3% |
| 1 mg | −42.9% |
| 4 mg | −57.0% |
| 8 mg | −81.4% |
| 12 mg | −82.4% |

86% of participants in the 12 mg group reached normal liver fat (below 5%) at 24 weeks [5]. Reductions were sustained through 48 weeks at −86.0% for the 12 mg group [5]. The MASLD signal is part of what drove the TRIUMPH Phase 3 program's scope to include liver-disease outcomes.

## Safety data from Phase 2

The retatrutide results record includes both efficacy and the adverse-event profile:

- **GI adverse events:** dose-related; nausea affected up to 45% of participants at 12 mg; the principal driver of the 18% discontinuation rate at that dose [1].
- **Heart-rate increase:** dose-dependent mean increase of approximately 5–7 bpm, peaking around week 24 [1].
- **Injection-site reactions:** ~8% of Phase 2 obesity participants [1].
- **Severe hypoglycemia:** none recorded in either Phase 2 trial [1][2].
- **Deaths:** none in either Phase 2 trial [1][2].
- **Body-composition:** absolute lean mass reduced alongside fat mass (fat-to-lean ratio more favorable than historical bariatric benchmarks) [4].

Long-term cardiovascular, renal, and weight-durability outcomes are still being measured in TRIUMPH-3 and NCT06383390 [9][10].

## What the TRIUMPH Phase 3 program is designed to measure

The Phase 2 retatrutide results — particularly the cardiometabolic endpoints — were the evidence base for the TRIUMPH Phase 3 program. TRIUMPH-3 (NCT05882045) targets a population with obesity and established cardiovascular disease, directly testing whether the Phase 2 cardiometabolic signal translates to hard outcomes (MACE, hospitalization, mortality) [9]. The cardiovascular/kidney outcomes trial (NCT06383390) adds a dedicated renal endpoint to the evidence base [10].

The Phase 3 program is ongoing; no interim or final results have been published as of mid-2026. For a direct comparison of the Phase 2 figures against tirzepatide's published Phase 3 data, see [retatrutide vs tirzepatide](/vs-tirzepatide).

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A spec-sheet digest of the published retatrutide trial record — figures logged to their studies, gaps left visible, no clinic and no prescription.