Retatrutide
Also known as LY3437943
Retatrutide is an investigational single peptide that activates the GIP, GLP-1, and glucagon receptors. Researchers study it to test whether adding glucagon receptor activity to incretin agonism increases weight reduction and metabolic effects.
Clinical-stage research
Size
8 options- Catalog no.
- RT5
- Specification
- 5mg *10vials
- Per kit
- 10 vials
For laboratory research use only. Not for human or animal consumption. Buyers must be 21 or older.
Overview
Retatrutide was developed by Eli Lilly under the code LY3437943. It is a single peptide engineered to act at three receptors: GIP, GLP-1, and glucagon. A fatty-acid side chain binds albumin and extends its half-life. In cell assays it is more potent at the GIP receptor than at the GLP-1 and glucagon receptors. After phase 2 trials in obesity and type 2 diabetes, the phase 3 TRIUMPH program has reported results in obesity, type 2 diabetes, knee osteoarthritis, and obstructive sleep apnea. It is not an approved drug.
Class: Triple GIP, GLP-1, and glucagon receptor agonist
Mechanism of action
How the compound acts, as described in the literature.
Activates GIP, GLP-1, and glucagon receptors. Discovery work reported roughly balanced glucagon and GLP-1 receptor activity, with greater activity at the GIP receptor.
GIP and GLP-1 receptor activity increases glucose-dependent insulin secretion and reduces food intake through central appetite pathways.
Glucagon receptor activity is proposed to raise energy expenditure. In obese mice, the added weight loss was attributed to glucagon-driven energy expenditure on top of incretin-driven reductions in calorie intake.
In the liver, glucagon receptor signaling promotes fatty acid oxidation and amino acid turnover, which is why liver fat is a common endpoint for glucagon-containing agonists.
Published research
Selected studies, each linked to its PubMed record. Summaries describe what the studies reported.
2026
Phase 3 RCT
PMID 42814954Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity.
Jastreboff AM, et al. · N Engl J Med
TRIUMPH-1 randomized 2,339 adults with obesity without diabetes for 80 weeks. Mean body-weight reductions were 17.6%, 23.7%, and 25.0% across three dose levels versus 3.9% with placebo; knee pain and sleep apnea endpoints also improved.
2026
Phase 3 RCT
PMID 42810372Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, parallel-group, randomised, placebo-controlled, phase 3 trial.
Bellido V, et al. · Lancet
TRIUMPH-2 randomized 1,152 adults with obesity and type 2 diabetes. At 80 weeks, mean body-weight reductions were 11.9% to 18.8% across three dose levels versus 5.1% with placebo, with improved glycemic control.
2022
Discovery and phase 1 study
PMID 35985340LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss: From discovery to clinical proof of concept.
Coskun T, et al. · Cell Metab
Reported the in vitro receptor profile of LY3437943, weight loss and improved glycemia in obese mice, and a phase 1 single-dose study in which weight reduction persisted up to day 43.
Evidence & safety
What the research does not show, and the adverse events and regulatory status it reports.
Retatrutide is investigational and not approved; Lilly has said it plans a US submission. In TRIUMPH-2, diarrhea, nausea, hypotension, and dysesthesia were more frequent than with placebo, and discontinuation for adverse events or death reached 12% at the middle dose level versus 5% with placebo. The phase 2 obesity trial reported dose-dependent heart-rate increases that peaked at 24 weeks.
Specifications
All sizes, exactly as catalogued.
| Catalog no. | Product | Specification | Vials per kit |
|---|---|---|---|
| RT5 | Retatrutide | 5mg *10vials | 10 |
| RT10 | Retatrutide | 10mg *10vials | 10 |
| RT15 | Retatrutide | 15mg *10vials | 10 |
| RT20 | Retatrutide | 20mg *10vials | 10 |
| RT30 | Retatrutide | 30mg *10vials | 10 |
| RT40 | Retatrutide | 40mg *10vials | 10 |
| RT50 | Retatrutide | 50mg *10vials | 10 |
| R60 | Retatrutide | 60mg *10vials | 10 |
For laboratory research use only. Not for human or animal consumption. Not intended to diagnose, treat, cure or prevent any disease. Research summaries are provided for educational purposes and do not describe this product’s use.