Retatrutide
What is Retatrutide?
GLP-3 R (LY3437943) is an investigational peptide developed by Eli Lilly that acts as a triple hormone receptor agonist, targeting GLP-1, GIP, and glucagon receptors. This next-generation compound is being studied for its powerful effects on weight loss, insulin sensitivity, and metabolic health. The unique triple-receptor mechanism may allow Retatrutide to outperform single or dual agonists like GLP-1 or GLP-2.
Potential Benefits Shown in Studies
- Rapid and sustained weight loss
- Reducing body fat and preserving muscle mass
- Controlling blood sugar and insulin resistance
- Decreasing appetite and food cravings
- Boosting metabolism and energy use
- Supporting liver health and fat reduction
- Improving markers of heart and metabolic function
Mechanisms of Action
GLP-3 R combines three synergistic metabolic pathways:
- GLP-3 receptor activation: Lowers blood sugar, suppresses appetite, slows gastric emptying
- GLP-3 receptor activation: Enhances insulin secretion and may protect beta cells
- GLP-3 receptor activation: Increases energy expenditure and fat oxidation
This triple-agonist profile helps drive both caloric reduction and metabolic acceleration — leading to substantial fat loss and improved insulin control.
Research Highlights
Unprecedented Weight Loss
In a 2023 Phase 2 trial published in The New England Journal of Medicine, participants receiving 12 mg of Retatrutide weekly lost an average of 24.2% of their body weight after 48 weeks — exceeding the average seen with Semaglutide or Tirzepatide.
Glucose Control in Type 2 Diabetes
In patients with type 2 diabetes, Retatrutide led to HbA1c reductions of up to 2.2% and improved fasting glucose. The effects were observed across all dosage levels.
Ongoing Phase 3 Trials
Retatrutide is now in the TRIUMPH program, a set of global Phase 3 trials assessing its long-term safety and efficacy in obesity, cardiovascular disease, and prediabetes.
Phase 3 Trial Results
Results for Phase 3 Trials showed massive loss in weight and much more.
Molecular Structure

GLP-3 R is a synthetic peptide with a modified sequence combining features of GLP-1, GIP, and glucagon analogues. (Exact amino acid sequence is proprietary and not publicly disclosed as of current publications.)
C₂₉₀H₄₄₅N₇₉O₈₇
~6058.78 g/mol
