Retatrutide / GLP-3: Emerging Research Overview

Research literature characterizes the GLP-family compounds along a receptor-engagement axis. Semaglutide is a single-receptor (GLP-1) agonist. Tirzepatide adds activity at GIP (the second incretin receptor) — making it a dual agonist. Retatrutide adds a third receptor: glucagon. It is the first GLP-family research analog targeting all three incretin/counterregulatory receptors simultaneously.

We cover the receptor differences in detail in our Semaglutide vs Tirzepatide comparison guide, which serves as useful background for understanding where Retatrutide sits in the broader literature.

Retatrutide for Obesity — A Phase 2 Trial (NEJM 2023, PMID 37314979) is the foundational publication. The trial administered weekly subcutaneous Retatrutide at doses of 1–12 mg in research cohorts over 48 weeks; the publication reports body-weight endpoints as its primary outcome.

Follow-up literature, including Diabetes Obes Metab 2024 (PMID 38866447), examines pharmacology and the broader Phase 2 program. Researchers replicating or extending these findings should refer directly to the published methodology.

Researchers selecting between GLP-1-S (Semaglutide), GLP-2-T (Tirzepatide), and GLP-3-R (Retatrutide) for new studies should reference the cited literature to match their compound choice to the receptor-engagement profile being investigated. Single GLP-1 pathway research → GLP-1-S. Dual GLP-1 + GIP pathway research → GLP-2-T. Triple-receptor research extending the 2023 NEJM publication → GLP-3-R.

BioInfinity Lab's research analogs of all three compounds ship ≥99% HPLC-verified material with a Janoshik Analytical COA, same-day from New York.

BioInfinity Lab supplies GLP-3-R as a lyophilized research analog in 5 mg and 10 mg vials. Storage is at −20 °C lyophilized; reconstituted at 2–8 °C with bacteriostatic water; typically used within 28 days post-reconstitution per laboratory SOP.