Retatrutide 20mg

Retatrutide (LY3437943) is a 39-amino-acid synthetic peptide characterized by simultaneous agonist activity at three G protein-coupled receptors: GLP-1R, GIPR, and GCGR. It is the first published compound to exhibit balanced tri-agonism across all three receptor subtypes.

Molecular Profile

The peptide backbone incorporates a C20 fatty diacid moiety conjugated via a linker to Lys20, conferring extended plasma half-life through albumin binding. Receptor activation follows the canonical Gαs-coupled cAMP signaling cascade at each target. The GLP-1R and GIPR components drive incretin-axis signaling, while GCGR activation engages hepatic cAMP/PKA-mediated glycogenolysis and gluconeogenic gene transcription pathways. Binding affinity ratios across the three receptors have been characterized by Coskun et al. (2022) using cell-based cAMP accumulation assays.

Published Data

Phase 2 clinical trial results (Jastreboff et al., NEJM 2023, n=338) reported dose-dependent pharmacodynamic effects across multiple metabolic biomarkers over a 48-week dosing period. Preclinical rodent data published in Nature (2022) characterized the tri-agonist receptor pharmacology and downstream signaling specificity relative to mono- and dual-agonist comparators. The compound remains under active investigation by Eli Lilly (Phase 3).

Research Relevance

Retatrutide provides a pharmacological tool for studying coordinated multi-receptor signaling across the incretin-glucagon axis — a pathway configuration not accessible with existing single- or dual-agonist reference compounds.