# Retatrutide Results in the Clinical Trials: Weight Loss, Kidney, Liver-Fat, and Diabetes Data

> Retatrutide results from Phase 1b and Phase 2 trials — 24.2% weight loss, 82.4% liver fat reduction, 37% UACR decrease, and 2.02% HbA1c reduction. All figures cited to source.

Weight loss, HbA1c reduction, liver fat, kidney markers — every figure from the published Phase 1 and Phase 2 record, cited to its source.

## What the results show — the plain version

Retatrutide is an investigational compound in Phase 3 trials. The results on this page come from Phase 1 and Phase 2 clinical trials — the human studies that tested whether it works and how well it is tolerated. These are real measured findings from controlled trials, not estimates or projections.

The headline finding: in a 48-week trial in people with obesity, the highest dose studied produced a mean -24.2% reduction in body weight versus -2.1% with placebo [1]. That is the single largest mean weight reduction ever reported in a Phase 2 obesity trial for a pharmaceutical agent. In separate trials: blood sugar markers improved substantially in type 2 diabetes participants [2]; liver fat fell by more than 80% in people with fatty liver disease [5]; and kidney markers showed favorable changes in both obesity and diabetes populations [11]. These retatrutide results are why the compound has generated so much attention.

## Weight loss: Phase 2 obesity trial (48 weeks)

The pivotal Phase 2 obesity trial enrolled 338 adults (BMI 30 or above, or 27–30 with a weight-related health condition) and randomized them to weekly subcutaneous doses of 1, 4, 8, or 12 mg, or placebo, for 48 weeks [1].

Mean body-weight change at 48 weeks by dose:
- **1 mg:** -8.7% (placebo: -2.1%)
- **4 mg:** -17.3% (placebo: -2.1%)
- **8 mg:** -22.8% (placebo: -2.1%)
- **12 mg:** -24.2% (placebo: -2.1%)

At 12 mg, 63% of participants achieved at least 20% total body weight loss by week 48 [13]. The weight-loss curve had not plateaued by the trial end, suggesting additional efficacy at longer durations [1, 6].

The 2025 review in *Biomolecules* characterizes the ~24% weight loss figure as a step-change in obesity pharmacology relative to prior incretin agents [6]. The 2025 systematic review across 53 phase 2/3 obesity trials confirms retatrutide's Phase 2 results as the highest published mean percentage weight loss in the field [9].

## Type 2 diabetes: glycemic and weight outcomes

The Phase 2 diabetes trial enrolled 281 adults with type 2 diabetes and studied doses up to 12 mg over 36 weeks [2].

- **HbA1c at 24 weeks:** -2.02% at 12 mg vs -0.01% placebo [2]
- **Body weight at 36 weeks:** -16.94% at 12 mg vs -3.00% placebo [2]
- **GI adverse events:** 35% of participants; no severe hypoglycemia; no deaths [2]

The 2025 *Cardiology in Review* analysis of cardiovascular-kidney-metabolic syndrome data reports HbA1c reduction of 2.02% in T2D and significant attenuation of UACR across the combined Phase 2 dataset [13].

## Liver fat: MASLD substudy results

The Phase 2a MASLD substudy enrolled 98 participants with confirmed liver fat of at least 10% (by MRI-PDFF) and no diabetes [5].

Relative liver-fat change at week 24:
- **1 mg:** -42.9% vs +0.3% placebo
- **4 mg:** -57.0%
- **8 mg:** -81.4%
- **12 mg:** -82.4%

At 12 mg, 86% of participants reached normal liver fat (below 5%) by week 24. At week 48, liver-fat reduction deepened to -86.0% at 12 mg [5]. This is the first Phase 2 liver-fat dataset for retatrutide; Phase 3 MASLD data are pending.

## Kidney outcomes: Phase 2 substudy and meta-analysis

The kidney-renal angle is the lens of this site, and the data are the most recently published in the retatrutide record.

The 2025 *Kidney International Reports* substudy measured kidney markers in Phase 2 participants [11]:
- **UACR reduction in T2D group (12 mg):** approximately -37% vs placebo
- **UACR reduction in obesity group (8–12 mg):** approximately -28–31% vs placebo
- **eGFR change in obesity group:** +5.3–8.5 mL/min/1.73m²

The 2025 *Maedica* systematic review and meta-analysis specifically in CKD-comorbid patients found significant glycemic and weight reduction, with lower doses (8 mg or below) showing greater HbA1c benefit and a renoprotective signal via albuminuria reduction [14]. The 2026 *Cardiology in Review* CKM syndrome review confirmed significant attenuation of UACR alongside the 24.2% weight loss and HbA1c figures from the combined Phase 2 record [13].

The TRANSCEND-CKD Phase 3 trial — the dedicated renal outcomes study — will provide the definitive kidney evidence; its design and baseline characteristics were published in 2025 [12].

## Phase 1b: first human efficacy signal

The Phase 1b trial in 72 adults with type 2 diabetes over 12 weeks was the first-in-human study [4]. Placebo-adjusted weight loss at the highest dose group was -8.96 kg (90% CI -11.16 to -6.75) over 12 weeks. Daily blood glucose fell 2.8 mmol/L at 3 mg [4]. The half-life of approximately 6 days was confirmed, establishing the pharmacokinetic rationale for once-weekly dosing [4]. Treatment-emergent adverse events occurred in 63% of participants, mostly GI.

For the full Retatrutide research record, see the [research page](/research). For information on how the compound produces these results, see [how does retatrutide work](/how-it-works).

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A blueprint-level reading of the published retatrutide trial record — Phase 2 figures logged to source, the kidney and cardiac questions marked open, and no clinic, prescription, or product behind the drafting sheet.