Retatrutide

Description

Overview

Retatrutide (research designation LY3437943) is a synthetic 39-amino-acid peptide conjugate supplied by G Peptide Labs strictly as a reference material for in-vitro and preclinical laboratory research. It is classified as a unimolecular triple agonist, engineered to interact with three incretin and metabolic receptor families of interest: the glucagon-like peptide-1 receptor (GLP-1R), the glucose-dependent insulinotropic polypeptide receptor (GIPR), and the glucagon receptor (GCGR). The molecule is built on a GIP-based backbone with non-coded residues (2-aminoisobutyric acid at positions 2 and 20, and alpha-methyl-leucine at position 13) and a C20 fatty-diacid side chain that supports albumin binding in experimental systems.

This listing is intended for qualified researchers, institutions, and laboratory professionals in Canada. It is not a drug, dietary supplement, or medical product, and it is not intended for human or veterinary use, diagnostic procedures, or any form of consumption.

Research Context

Retatrutide has become a widely referenced tool compound in the study of multi-receptor incretin signalling. Researchers investigate it as a model molecule for examining how simultaneous engagement of GLP-1R, GIPR, and GCGR is thought to differ from single- or dual-receptor agonism in cellular and preclinical model systems.

• Used in receptor-binding and signalling assays to characterize relative potency and functional selectivity across the three target receptors in vitro.
• Studied in preclinical animal models to explore energy-balance, glucose-handling, and lipid-metabolism pathways at the tissue and whole-organism level.
• Applied in structural biology efforts, including cryo-EM work aimed at resolving how a single peptide accommodates three distinct class B G-protein-coupled receptors.

All described activities reflect laboratory and preclinical literature only. No statement here should be interpreted as evidence of safety, efficacy, or benefit in humans.

Mechanism of Interest

The scientific interest in Retatrutide centres on its balanced, engineered agonism. In published cell-culture characterization, the peptide showed higher relative potency at the GIP receptor and comparatively lower relative potency at the glucagon and GLP-1 receptors versus each native ligand. This engineered profile makes it a useful probe for researchers investigating how the ratio of receptor activation influences downstream cyclic-AMP signalling, beta-arrestin recruitment, and receptor internalization in model systems.

• GLP-1R engagement is examined in the context of incretin-pathway signalling studies.
• GIPR engagement is studied for its contribution to combined incretin responses in vitro.
• GCGR engagement is investigated in relation to hepatic and energy-expenditure pathways in preclinical models.

Specifications

• Compound: Retatrutide (LY3437943)
• CAS Number: 2381089-83-2
• Molecular Formula: C221H342N46O68
• Molecular Weight: approximately 4731.3 g/mol (average mass)
• Sequence class: 39-residue synthetic peptide, GIP-based backbone with Aib (positions 2, 20), alpha-methyl-leucine (position 13), C-terminal amide, and a C20 fatty-diacid side chain
• Purity: 99%+ by HPLC (batch-specific value stated on the certificate of analysis)
• Physical form: lyophilized white to off-white powder
• Intended use: laboratory research use only (RUO); not for human or animal use

Handling, Reconstitution & Storage

Retatrutide should be handled only by trained personnel using appropriate laboratory practice and protective equipment. The following are general handling notes for the reference material and are not directions for any in-life application.

• Storage of lyophilized powder: store sealed at -20 degrees C, protected from light and moisture; the powder is generally stable for extended periods under these conditions.
• Reconstitution: peptides of this class are typically reconstituted with sterile bacteriostatic or research-grade water; introduce the solvent slowly against the vial wall and allow it to dissolve without vigorous agitation.
• Reconstituted solution: keep refrigerated at 2-8 degrees C for short-term laboratory work and aliquot to minimize freeze-thaw cycles; store aliquots frozen for longer intervals.
• Avoid: repeated freeze-thaw cycles and prolonged exposure to room temperature, which can degrade peptide integrity.

Quality & Verification

Every batch of Retatrutide from G Peptide Labs is supplied with third-party analytical documentation so that researchers can verify identity and purity before use.

• Certificate of Analysis (COA): includes HPLC purity, mass-spectrometry confirmation of molecular weight, and batch identification.
• Third-party testing: independent laboratory verification supports the reported purity and identity.
• Traceability: each vial is lot-numbered so documentation can be matched to the specific batch received.

G Peptide Labs is a Canadian research-peptide supplier. Products are sold for laboratory and research purposes only and must be used in compliance with all applicable institutional, provincial, and federal regulations.

Selected Research

Peer-reviewed references provided for scientific context; they describe laboratory and preclinical findings only.

1. LY3437943, a novel triple glucagon, GIP, and GLP-1 receptor agonist for glycemic control and weight loss: From discovery to clinical proof of concept. Cell Metabolism Coskun T, et al., 2022. PMID: 35985340
2. LY3437943, a novel triple GIP, GLP-1, and glucagon receptor agonist in people with type 2 diabetes: a phase 1b, multicentre, double-blind, placebo-controlled, randomised, multiple-ascending dose trial. The Lancet Urva S, et al., 2022. PMID: 36354040
3. Structural insights into the triple agonism at GLP-1R, GIPR and GCGR manifested by retatrutide. Cell Discovery Li W, et al., 2024. PMID: 39019866