Retatrutide overview

Retatrutide (also known as LY3437943) is an investigational synthetic peptide being studied for chronic weight management and metabolic disease. What makes it different from earlier incretin medicines is that it’s designed to activate three hormone receptors at once: GLP-1, GIP, and glucagon—a “triple-agonist” approach intended to reduce appetite, improve glucose control, and increase energy expenditure. 

Metabolic and weight-loss effects seen in studies

Substantial weight reduction in adults with obesity

In a randomized, placebo-controlled Phase 2 trial in adults with obesity, retatrutide produced large reductions in body weight over 48 weeks, with higher doses associated with greater weight loss. 

Improvements in type 2 diabetes outcomes

In a separate Phase 2 trial in people with type 2 diabetes, retatrutide led to clinically meaningful HbA1c reductionsand robust body-weight loss compared with placebo (and compared with an active comparator in the trial design). 

Body composition findings

Additional published analyses report that retatrutide reduces fat mass substantially, with lean-mass changes proportionate to overall weight loss in studied populations (consistent with patterns seen across obesity pharmacotherapy). 

Tolerability and safety profile in clinical trials

Across published Phase 2 studies, the most common side effects were gastrointestinal (typical of incretin-based therapies), and discontinuations occurred in some participants. Overall safety findings in these trials were described as consistent with the broader GLP-1/GIP therapeutic class, though longer and larger Phase 3 datasets are intended to further define safety. 

Development status

Retatrutide remains in clinical development within Lilly’s TRIUMPH Phase 3 program (with multiple studies registered on ClinicalTrials.gov), including studies in obesity/overweight and obesity-related complications. 

Retatrutide specifications

From PubChem, retatrutide is listed with:

• CAS: 2381089-83-2

• Molecular formula: C221H342N46O68

• Molecular weight: ~4731 g/mol 

(Note: suppliers may list salt forms that can differ in reported mass.)

Important notice

This information is provided for scientific and educational purposes. Retatrutide is an investigational drug studied in clinical trials and is not established for routine clinical use outside approved indications/authorizations. Any research material should be handled and described as for in vitro research by qualified professionals and not marketed as a drug, supplement, food, or cosmetic.

References

1. Jastreboff AM, et al. Triple–Hormone-Receptor Agonist Retatrutide for Obesity. New England Journal of Medicine (2023). 

2. Rosenstock J, et al. Retatrutide, a GIP, GLP-1 and glucagon receptor agonist, in type 2 diabetes. The Lancet(2023). 

3. PubMed record for Rosenstock J, et al. (2023). 

4. Coskun T, et al. Effects of retatrutide on body composition… (PubMed-indexed publication). 

5. ClinicalTrials.gov: Retatrutide (LY3437943) studies (example master protocol entry). 

6. Lilly Medical: Overview of the TRIUMPH Phase 3 program. 

7. PubChem compound record: Retatrutide (formula, CAS, molecular weight). 

Complete Disclaimer

This product is sold exclusively for laboratory research purposes under Section 351 of the Public Health Service Act. It is not intended for human or veterinary use, nor for diagnostic, therapeutic, or cosmetic applications. Purchaser certifies they are properly licensed and equipped to handle research compounds in compliance with all local, state, and federal regulations. EaglePeptideUSA assumes no liability for misuse or unauthorized handling. By purchasing, you affirm this material will not be introduced into interstate commerce or used in food/drug products.