Retatrutide

Retatrutide (LY3437943) Triple Receptor Agonist of GLP 1, GIP, and Glucagon | Research Use Only

What it is

Retatrutide, also known as LY3437943, is an investigational peptide engineered as a triple receptor agonist designed to activate the GLP 1 receptor, the GIP receptor, and the glucagon receptor, also called GCGR. This multi pathway design is being evaluated in clinical research as a next generation incretin based approach for obesity and metabolic endpoints. (nejm.org)

Origins and development

Retatrutide was developed by Eli Lilly and Company as part of its metabolic research pipeline and has been evaluated in controlled clinical studies, including a Phase 2 randomized trial published in peer reviewed literature. (nejm.org)

Molecular profile

PubChem lists retatrutide with the molecular formula C221H342N46O68 and a molecular weight of about 4731 g per mol. Some technical supplier listings describe it as a peptide around 39 amino acids, which can be useful for cross checking identity descriptions in research settings, but chemical registry sources should be treated as the anchor for formula and mass. (pubchem.ncbi.nlm.nih.gov) (novoprolabs.com)

Scientific overview

Retatrutide fits within the broader research category of poly agonist incretin therapeutics. In simplified terms, researchers are interested in the combined signaling profile because GLP 1 receptor activity is associated with satiety pathways and glucose dependent insulin secretion, GIP receptor activity is studied for complementary incretin biology alongside GLP 1, and GCGR activation is investigated for potential effects on energy expenditure and lipid metabolism when balanced with incretin pathways. The scientific goal is to understand whether coordinated activation across these receptors can produce broader metabolic effects than single or dual agonist designs while maintaining tolerability appropriate for continued study. (nejm.org)

Clinical research 

Retatrutide is not FDA approved and remains investigational, with efficacy and safety being evaluated in ongoing trials. In a widely cited Phase 2 trial in adults with obesity, treatment over 48 weeks was associated with substantial reductions in body weight compared with placebo, reinforcing interest in triple agonist incretin research. (nejm.org)

What researchers study with retatrutide

Key research focus areas often include
• Appetite and satiety signaling across central and peripheral pathways
• Gastrointestinal motility and gastric emptying dynamics
• Glucose homeostasis mechanisms including glucose dependent insulin secretion and glucagon modulation
• Energy balance models including interest in GCGR linked pathways

Regulatory and compliance notice

Research Use Only. Not for human or veterinary use. The FDA has warned about unapproved GLP 1 related products, including products that are falsely labeled for research purposes, being sold with unknown quality and potential risk. (fda.gov)

Origins and development at Eli Lilly

Retatrutide, code named LY3437943, is an investigational triple receptor agonist created and advanced by Eli Lilly and Company as part of its metabolic disease research program. In published clinical research, it is described as a single peptide engineered to activate the GIP, GLP 1, and glucagon receptors, and it is conjugated to a fatty diacid moiety, a design approach commonly used to extend time in circulation and support less frequent administration in clinical development settings.

• Sponsor and trial oversight: In the pivotal Phase 2 obesity study published in The New England Journal of Medicine, the sponsor, Eli Lilly, designed and oversaw the trial, with site investigators collecting data and the sponsor handling monitoring and analysis.

• Early phase clinical proof of concept: An early phase study of LY3437943 published in 2022 reports supportive pharmacokinetic and pharmacodynamic findings and lists Eli Lilly and Company as the funder, supporting the transition into Phase 2 development.

• Ongoing clinical program: Lilly continues to run multiple retatrutide studies across obesity and related cardiometabolic areas, documented in registries and Lilly Trials listings, reflecting an active and expanding clinical development program.

Citations and references

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

2. Coskun T, et al. Early phase study of LY3437943 (retatrutide) reporting pharmacokinetic and pharmacodynamic findings, funded by Eli Lilly. Clinical research publication indexed in PubMed (2022). (pubmed.ncbi.nlm.nih.gov)

3. Eli Lilly and Company Trials Listing Retatrutide clinical trial program entry. (trials.lilly.com)

4. PubChem Retatrutide compound record including molecular formula and molecular weight. (pubchem.ncbi.nlm.nih.gov)

5. U.S. Food and Drug Administration FDA concerns with unapproved GLP 1 drugs used for weight loss, including products falsely labeled for research purposes. (fda.gov)

6. NovoProLab technical listing Used only as a cross check reference for reported peptide length and identity descriptors.
   (novoprolabs.com)