- Single-molecule triple receptor agonist
- Targets GIP, GLP-1 and glucagon receptors
- Published randomised Phase 2 human data are available
- Multiple Phase 3 TRIUMPH studies reported positive topline results in 2026
- Remains investigational and unapproved
Retatrutide
Retatrutide Research Overview
GIP + GLP-1 + glucagon triple receptor agonist
Research Information & Evidence Summary
RResearch use onlyNot for human or veterinary use
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Research reminder
For laboratory and research use only. This material is provided for research information and is not medical advice, a dosing recommendation, or guidance for human or veterinary use.
Last reviewed: 7 September 2026
Overview
Retatrutide (LY3437943) is an investigational single-molecule agonist of the glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1) and glucagon receptors. Its research programme is focused on cardiometabolic disease, including obesity and related conditions.
Published Phase 2 data established proof-of-concept in adults with obesity. During 2026, Lilly also reported positive topline results from multiple Phase 3 TRIUMPH studies. Retatrutide remains investigational and has not been approved by a regulatory agency.
Mechanisms
How the research fits together
GIP receptor: incretin signalling relevant to post-prandial insulin response and energy balance.
GLP-1 receptor: incretin signalling associated with glucose-dependent insulin secretion, appetite regulation and slowed gastric emptying.
Glucagon receptor: adds a distinct energy-expenditure and hepatic-metabolism pathway to the incretin components. Retatrutide is designed to combine all three activities in one molecule.
Evidence
Research evidence
| Study / source | Finding | Evidence level |
|---|---|---|
| Jastreboff et al., NEJM 2023 | Randomised Phase 2 obesity trial demonstrated substantial mean weight reduction over 48 weeks, with gastrointestinal adverse events most common | Human Phase 2 |
| Lilly TRIUMPH-1, 2026 | Positive Phase 3 topline obesity results reported; detailed peer-reviewed publication should be consulted as it becomes available | Phase 3 topline |
| Lilly TRIUMPH-2 / TRIUMPH-3, 2026 | Positive Phase 3 topline results in obesity with type 2 diabetes and severe obesity with cardiovascular disease | Phase 3 topline |
Comparison
Research comparison
| Feature | This research | Alternative |
|---|---|---|
| Feature | Retatrutide | Research context |
| Receptor profile | GIP + GLP-1 + glucagon | Triple agonist |
| Clinical evidence | Phase 2 published; Phase 3 topline reported | Investigational programme |
| Regulatory status | Not approved | Research/clinical-trial context only |
Safety & limitations
Research considerations
- Investigational molecule; safety and efficacy remain under regulatory evaluation
- Published Phase 2 data reported gastrointestinal adverse events as the most common treatment-emergent events
- Dose-dependent heart-rate increases were observed in Phase 2
- Commercial research material is not equivalent to an approved medicinal product
- NRVE information is for laboratory and research reference only