Le Retatrutide (LY3437943) represents a major advance in metabolic modulation research. This synthetic peptide, developed by Eli Lilly, is the first triple agonist of GLP-1, GIP and Glucagon receptors to have reached phase 3 of clinical trials. Unlike existing therapies such as semaglutide (GLP-1 monoagonist) or tirzepatide (dual GLP-1/GIP agonist), Retatrutide simultaneously mobilizes three distinct hormonal pathways regulating appetite, energy expenditure, and lipid metabolism. The results published in the New England Journal of Medicine in 2023 showed a reduction in body weight of -24,2% over 48 weeks at a dose of 12 mg, surpassing all treatments previously evaluated in comparable studies. This guide explores the molecular mechanisms, available clinical data, and research protocols associated with Retatrutide.
⚠️ Research use only. Not intended for human consumption. All information presented here is derived from scientific literature and is provided for informational purposes only for the research community.
What is Retatrutide?
Retatrutide is a synthetic peptide designed to act simultaneously on three key hormone receptors involved in metabolism:
- GLP-1 (Glucagon-Like Peptide-1) — Stimulates glucose-dependent insulin secretion, slows gastric emptying, reduces appetite via hypothalamic signals.
- GIP (Glucose-dependent Insulinotropic Polypeptide) — Potentiates the insulin response, promotes energy storage in brown adipose tissue, modulates thermogenesis.
- Glucagon — Increases resting energy expenditure, stimulates hepatic lipolysis, accelerates fatty acid oxidation.
Differences with Semaglutide and Tirzepatide
Le Semaglutide (Ozempic®, Wegovy®) is a GLP-1 monoagonist: it acts only on the GLP-1 receptor. Tirzepatide (Mounjaro®, Zepbound®) is a dual GLP-1/GIP agonist, introducing synergy between two axes. Retatrutide goes further by also activating the Glucagon receptor, adding a third mechanism of action that amplifies resting calorie expenditure. This triple activation explains the significantly greater weight loss results observed in phase 2.
Clinical Results — Phase 2 (Jastreboff et al., 2023)
The phase 2 study of Retatrutide (NCT04881760) was published in the New England Journal of Medicine by Jastreboff AM et al. in July 2023. This is a randomized, double-blind, placebo-controlled trial conducted on 338 participants with a BMI ≥ 27 kg/m².
Main results at 48 weeks
Dose 12 mg
Dose 8 mg
Dose 4 mg
(48 weeks)
Participants receiving 12 mg of Retatrutide weekly lost an average of 24.2% of their initial body weight, or approximately 24.2 kg for an individual weighing 100 kg. No previous study of comparable duration had produced such results.
Effects on metabolic biomarkers
Beyond weight loss, the study documented significant improvements in several biomarkers: a reduction in serum triglycerides (-44%), improved insulin sensitivity (HOMA-IR -62%), a decrease in HbA1c in prediabetic subjects, and a reduction in waist circumference (-22 cm on average). These effects suggest an overall metabolic impact extending beyond just fat mass reduction.
Reference: Jastreboff AM, Kaplan LM, Frías JP, et al. “Triple–Hormone-Receptor Agonist Retatrutide for Obesity—A Phase 2 Trial. » N Engl J Med. 2023;389(6):514-526. doi:10.1056/NEJMoa2301972
Research Guides — Scientific Articles
To learn more about Retatrutide and GLP-1 peptides, consult our detailed scientific guides:
Retatrutide R3 — Available for Research
MyPeptide offers lyophilized Retatrutide (R3) for exclusive use in scientific research, with a purity ≥ 98% verified by HPLC. Each batch is accompanied by a Certificate of Analysis (CoA).
Discreet delivery · Secure payment · Intended exclusively for laboratories and scientific researchers. Not for human consumption.
Frequently Asked Questions about Retatrutide
What is Retatrutide?
Retatrutide (LY3437943) is a triple agonist peptide that simultaneously targets GLP-1, GIP, and glucagon receptors. Developed by Eli Lilly, it demonstrated a 24.2% weight reduction in a 48-week Phase 2 clinical trial. It is currently in Phase 3 clinical trials.
What is the difference between Retatrutide and Semaglutide?
Semaglutide (Ozempic, Wegovy) is a monoagonist of GLP-1. Retatrutide is a triple agonist of GLP-1, GIP, and glucagon, which explains its superior efficacy in weight loss observed in clinical studies. The synergy between the three receptors generates increased energy expenditure and enhanced satiety.
Is Retatrutide approved for human consumption?
No. Retatrutide is currently in phase 3 clinical trials and has not yet received regulatory approval (FDA, EMA). MyPeptide offers it exclusively for scientific research purposes, not for human consumption.
What are the clinical outcomes of Retatrutide?
The phase 2 study published in the NEJM (Jastreboff AM et al., 2023) showed an average reduction in body weight of 24.2% over 48 weeks with the 12 mg dose, compared to 15.9% for tirzepatide over a similar period. Significant improvements in triglycerides (-44%), HOMA-IR (-62%), and waist circumference (-22 cm) were also documented.
How is lyophilized Retatrutide stored?
Lyophilized Retatrutide should be stored at -20°C, protected from light and moisture. After reconstitution with sterile bacteriostatic water, the product must be stored at +4°C and used within 4 weeks. Avoid repeated freeze-thaw cycles, which can degrade the peptide structure.
Legal notice: The Retatrutide R3 offered on MyPeptide is intended exclusively for scientific research use in laboratories. It is not approved by health authorities (FDA, ANSM, EMA) for human or animal consumption, medical diagnosis, or any therapeutic use. Any use outside the context of research is strictly prohibited and is the sole responsibility of the purchaser.