Retatrutide (LY3437943) is a synthetic, lipid-conjugated 39-amino-acid peptide that acts as a unimolecular triple agonist of the glucose-dependent insulinotropic polypeptide receptor (GIPR), the glucagon-like peptide-1 receptor (GLP-1R), and the glucagon receptor (GCGR). It is supplied as a research-use-only reference material for in-vitro and structural studies of these class B GPCRs. Reported chemistry: molecular formula C₂₂₁H₃₄₂N₄₆O₆₈, molecular weight ≈ 4731.3 g/mol, CAS 2381089-83-2.
Analytical identity
Retatrutide is cataloged under CAS 2381089-83-2 with the molecular formula C₂₂₁H₃₄₂N₄₆O₆₈ and a molecular weight of approximately 4731.3 g/mol. It is a 39-residue peptide built on a GIP-derived backbone, supplied as a lyophilized powder at ≥98% (HPLC) for use as an analytical and experimental reference standard. Chemistry values are drawn from public PubChem/literature records and should be independently confirmed against a certificate of analysis.
Structure and modifications
The sequence incorporates three non-coded residues — 2-aminoisobutyric acid at positions 2 and 20 (Aib2, Aib20) and α-methyl-L-leucine at position 13 (αMeLeu13) — together with a C20 fatty-diacid moiety attached via a γGlu/AEEA linker to a lysine side chain, and a C-terminal amide. These features are described in the literature as influencing backbone conformation, proteolytic resistance, and albumin association in in-vitro and pharmacokinetic study contexts.
Receptor targets and mechanism themes
In the research literature Retatrutide is characterized as a single molecule that engages three class B G-protein-coupled receptors — GIPR, GLP-1R, and GCGR. Structural studies (e.g., cryo-EM of peptide-receptor complexes) examine how the engineered GIP backbone is recognized at each receptor, making the compound a tool for comparative receptor-activation, binding, and signaling-bias investigations in cell-based and biochemical assays.
Research handling context
This listing describes Retatrutide solely as a characterized reference material for laboratory research. It is not intended for human or veterinary use, diagnostic application, or any in-vivo administration. Investigators are responsible for confirming identity, purity, and suitability for their specific experimental protocols.
Every Retatrutide order includes a sealed, lot-controlled vial, the completed lot documentation, and a handling & storage card. Product-specific handling follows the supplied documentation and institutional SOPs.
Evidence limits and research safety
Research findings can differ by model, assay, purity, formulation, and study design. Published cell, biochemical, and pre-clinical observations do not establish human or veterinary safety, efficacy, dosing, or suitability. Researchers should review the applicable SDS, institutional safety procedures, waste requirements, and lot-specific documentation before handling any reference material.
Related research
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Credible sources
- PubChem — Retatrutide (search)
- PubMed — Retatrutide (search)
- Structural insights into the triple agonism at GLP-1R, GIPR and GCGR (PMC11255275)