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.
Credible sources
- PubChem — Retatrutide (search)
- PubMed — Retatrutide (search)
- Structural insights into the triple agonism at GLP-1R, GIPR and GCGR (PMC11255275)