Retatrutide
Also called LY3437943
Educational only, not medical advice. Dosaly reports what has been studied; it isn't a recommendation to use Retatrutide or any amount of it. Talk to a clinician.
Investigational; not approved as a medicine by the FDA or EMA (as of October 2026).
Research applications
- Obesity (phase 2 and phase 3 TRIUMPH trials)
- Type 2 diabetes (phase 2 trial)
- Fatty liver disease (phase 2a study)
- Energy use and liver fat (glucagon receptor)
What studies have looked at, not proven uses.
What it is
Retatrutide is an experimental peptide from Eli Lilly that acts on three hormone receptors. It's being studied in large trials for obesity and diabetes and isn't approved yet.
More detail
Retatrutide is an investigational synthetic peptide from Eli Lilly that activates three hormone receptors at once: GIP, GLP-1 and glucagon. The glucagon part is studied for its possible effects on energy use and liver fat. Phase 2 trials in obesity and in type 2 diabetes were published in 2023, a phase 2a study looked at fatty liver disease, and the first phase 3 results from the TRIUMPH program, in adults with obesity with and without type 2 diabetes, were published in 2026. Gastrointestinal effects were the most commonly reported side effects. It remains under study.
Evidence listed here
- 4 human studies
Results from cells and animals often don't carry over to people. How to read peptide research
Molecular info
- Class
- Lipidated peptide (GIP, GLP-1 and glucagon receptor agonist)
- Length
- 39 amino acids
- Sequence
- Not shown here
- Research areas
- Weight, Metabolic
Includes non-standard amino acids and a fatty-acid chain that extends its action to about a week.
Research
- Human studyN Engl J Med · 2026Retatrutide, a Triple Hormone Receptor Agonist, for Treatment of Obesity.
Phase 3 randomized trial in adults with obesity without diabetes.
- Human studyLancet · 2026Retatrutide in adults with obesity and type 2 diabetes (TRIUMPH-2): a double-blind, parallel-group, randomised, placebo-controlled, phase 3 trial.
Phase 3 randomized trial (TRIUMPH-2) in obesity with type 2 diabetes.
- Human studyN Engl J Med · 2023Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial.
Phase 2 randomized trial in adults with obesity.
- Human studyLancet · 2023Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, for people with type 2 diabetes: a randomised, double-blind, placebo and active-controlled, parallel-group, phase 2 trial conducted in the USA.
Phase 2 randomized trial in type 2 diabetes.