What did retatrutide trials report for HbA1c, liver, lipids?
The laboratory results the published retatrutide trials reported: HbA1c by dose arm, ALT, AST, ELF, Pro-C3 and lipids. Research context only.
Research use only. This page provides scientific background and community-report context. Every compound sold here is supplied strictly for in-vitro research, not for human or veterinary use. Nothing on this page is a protocol, a recommendation or medical advice. Laboratory decisions belong to a physician.
TL;DR: laboratory findings depend on the trial and endpoint
The question people actually type: what did the retatrutide trials report for hba1c, liver enzymes and lipids?
What the published data say: trials reported HbA1c reductions and lipid changes, while the liver substudy found no consistent ALT, AST, FIB-4 or ELF change versus placebo. [PMID 37385280; PMID 42250575; PMID 38858523]
What the documented search did not identify: the gap is in published results: the PubMed search on 12 September 2026 found no TRIUMPH outcome publication. This does not mean its laboratory endpoints were never studied. [PubMed: retatrutide AND TRIUMPH; PMID 41090431]
What research communities report: in the Reddit corpus we track, 136 question posts in 12 months, 10 in the 4 to 12 Sept 2026 window matched this pattern. These are reports, not evidence of frequency or an effect.
What HbA1c change did the trials report by dose arm?
The phase 2 trial in participants with type 2 diabetes reported dose-dependent HbA1c changes at 24 weeks; the registry describes the study intervention as subcutaneous injection [NCT04867785, interventions module]. The table gives least-squares mean changes from baseline in HbA1c, in percentage points, with the comparators alongside each arm. “Escalation,” “slow” and “fast” identify published study groups. PeptidesDirect does not sell dulaglutide. [PMID 37385280; NCT04867785]
These are the study arms of the cited trials, not an application protocol for research vials.
- HbA1c change at 24 weeks
- -0.43
- Comparator changes at 24 weeks
- Placebo -0.01; dulaglutide 1.5 mg -1.41
- HbA1c change at 24 weeks
- -1.39
- Comparator changes at 24 weeks
- Placebo -0.01; dulaglutide 1.5 mg -1.41
- HbA1c change at 24 weeks
- -1.30
- Comparator changes at 24 weeks
- Placebo -0.01; dulaglutide 1.5 mg -1.41
- HbA1c change at 24 weeks
- -1.99
- Comparator changes at 24 weeks
- Placebo -0.01; dulaglutide 1.5 mg -1.41
- HbA1c change at 24 weeks
- -1.88
- Comparator changes at 24 weeks
- Placebo -0.01; dulaglutide 1.5 mg -1.41
- HbA1c change at 24 weeks
- -2.02
- Comparator changes at 24 weeks
- Placebo -0.01; dulaglutide 1.5 mg -1.41
The phase 3 TRANSCEND-T2D-1 monotherapy trial included 537 participants with type 2 diabetes, assigned to retatrutide or placebo by once-weekly subcutaneous injection. At 40 weeks, mean HbA1c changes were -1.69% in the 4 mg arm, -1.86% in the 9 mg arm and -1.94% in the 12 mg arm, versus -0.81% with placebo. Reported differences versus placebo were -0.88, -1.04 and -1.12 percentage points, respectively, all p<0.0001. These are a separate trial's results at a different follow-up window. [PMID 42250575; NCT06354660]
What did the liver substudy report for ALT, AST, ELF and Pro-C3?
The liver substudy reported no consistent change in mean ALT, AST, FIB-4 or ELF versus placebo. It followed 98 participants with at least 10% liver fat within the phase 2 obesity trial over 48 weeks of once-weekly subcutaneous retatrutide or placebo. Mean baseline ALT ranged from 29.1 to 35.5 IU/l and AST from 23.1 to 25.0 IU/l across arms; the authors described these baseline enzyme levels as normal. [PMID 38858523; NCT04881760]
These are the study arms of the cited trials, not an application protocol for research vials.
At week 24, the 4 mg arm reported ALT change of -30.3% versus -13.5% with placebo, and AST change of -19.9% versus -7.2%. Only this arm differed significantly from placebo for these enzymes, with P values of 0.044 and 0.042, respectively. That isolated comparison does not replace the authors' overall finding. [PMID 38858523, Table 2]
ELF rose slightly in most arms at week 24: the 4 mg arm reported -0.6% versus +9.2% with placebo, the only significant between-group difference for ELF. Pro-C3, a fibrogenesis marker, changed at week 24 by -11.9%, -23.3%, -22.7% and -26.4% in the 1, 4, 8 and 12 mg study arms, respectively, versus -5.7% with placebo. The Pro-C3 differences were significant at 4 mg and above. These endpoints had different reported patterns. [PMID 38858523, Table 2]
What did the trials report for lipids and lipoproteins?
The liver substudy within the obesity trial, 48 weeks of once-weekly subcutaneous retatrutide or placebo, reported dose-dependent triglyceride reductions from baseline. At week 48, triglyceride changes were -21.8%, -37.0%, -41.1% and -49.4% in the 1, 4, 8 and 12 mg study arms, respectively, versus -4.1% with placebo. [PMID 38858523, Table 2]
These are the study arms of the cited trials, not an application protocol for research vials.
Ruotolo's post hoc analysis reported placebo-adjusted apoB changes of -21.4% in the type 2 diabetes trial at 36 weeks and -24.2% in the obesity trial at 48 weeks. Total LDL particle changes were -19.7% and -23.5%, respectively; small LDL particle changes were -32.6% and -32.3%. The population and follow-up window belong with each number. [PMID 42608321]
A meta-analysis reported pooled differences of -21.88 mg/dL for total cholesterol, -13.10 mg/dL for LDL-C and -40.90 mg/dL for triglycerides, with no significant HDL-C effect. These pooled estimates are distinct from individual-arm percentage changes and from particle measurements. [PMID 42371360]
Which laboratory endpoints were pre-specified in the registry?
The registry entries pre-specified different endpoints across the trial programs. The registry entry for the phase 2 trial in participants with obesity listed no laboratory endpoint among its primary and secondary outcomes; its listed outcomes concerned body weight, BMI or waist circumference. The phase 2 trial entry for participants with type 2 diabetes specified HbA1c and fasting glucose, but no lipid or enzyme endpoint. Published substudy findings therefore need to be distinguished from the registry's listed outcomes. [NCT04881760; NCT04867785]
TRIUMPH-1 listed triglycerides, non-HDL-C, fasting insulin, hsCRP, HbA1c and eGFR as secondary outcomes through week 80, but no ALT or AST endpoint. Its registry status was completed with no results posted when retrieved on 12 September 2026. A listed endpoint establishes what the registry specified, not what result was observed. [NCT05929066]
What is still missing from the phase 3 record?
Registry results and journal publications were at different stages: no phase 3 retatrutide trial had posted registry results in the ClinicalTrials.gov search on 12 September 2026, although TRANSCEND-T2D-1 had published HbA1c results. The registry search for retatrutide returned 34 studies; only the phase 2 entries carried posted results. [NCT04881760; NCT04867785; PMID 42250575]
The PubMed search “retatrutide AND TRIUMPH” returned 6 hits on that date and no outcome publication; the TRIUMPH-specific paper was a design and rationale article. [PMID 41090431]
Retatrutide has no approved medicine label and remains under clinical development. For regulatory contrast, Mounjaro's approved product information reports pooled tirzepatide arms from SURMOUNT-1, including triglyceride changes of -27.6% versus -6.3% with placebo. Those figures belong to tirzepatide. PeptidesDirect does not sell tirzepatide. [PMID 42250575; EMA, Mounjaro EPAR product information, SmPC 5.1]
Products mentioned
Retatrutide (LY3437943) is a synthetic 39-amino-acid peptide that acts on three receptors at once: GLP-1, GIP and glucagon. Supplied as a lyophilized powder for in-vitro research, with a batch-specific third-party certificate of analysis.
Sources
- Rosenstock, 2023. Phase 2 type 2 diabetes trial. Lancet 402:529-544. PMID 37385280; NCT04867785.
- Bajaj, 2026. Phase 3 monotherapy trial. Lancet 407:2402-2413. PMID 42250575; NCT06354660 (TRANSCEND-T2D-1).
- Sanyal, 2024. Liver substudy. Nat Med 30:2037-2048. PMID 38858523; PMC11271400, Table 2; NCT04881760.
- Ruotolo, 2026. Post hoc analysis of both phase 2 trials. Diabetes Obes Metab. PMID 42608321; NCT04881760; NCT04867785.
- Simental-Mendia, 2026. Meta-analysis of retatrutide RCTs. High Blood Press Cardiovasc Prev 33:503-516. PMID 42371360.
- ClinicalTrials.gov, retrieved 12.09.2026. Phase 2 obesity registry entry. NCT04881760.
- ClinicalTrials.gov, retrieved 12.09.2026. Phase 2 T2D registry entry. NCT04867785.
- ClinicalTrials.gov, retrieved 12.09.2026. TRIUMPH-1. NCT05929066.
- ClinicalTrials.gov API v2, retrieved 12.09.2026. Query retatrutide: TRIUMPH-2, NCT05929079; TRIUMPH-3, NCT05882045; TRANSCEND-T2D-1, NCT06354660.
- PubMed, searched 12.09.2026. Query retatrutide AND TRIUMPH; design and rationale article, PMID 41090431.
- EMA, authorised 15 September 2022, PDF retrieved 12.09.2026. Mounjaro EPAR product information (SmPC 5.1).
Research use only. Retatrutide is supplied here as a research chemical strictly for in-vitro research, not for human or veterinary use. Nothing on this page is an application protocol or medical advice.
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