Tirzepatide vs Retatrutide Research Comparison | QSC
QSC · RESEARCH CATALOG
Tirzepatide vs Retatrutide: Research Comparison Dual GLP-1R/GIPR vs Triple GLP-1R/GIPR/GCGR · Mechanism Comparison · Clinical Trial Data · QSC ≥99% HPLC
Tirzepatide (Mounjaro/Zepbound, Eli Lilly) and Retatrutide (LY3437943, Phase 3) represent the dual and triple agonist generations of the incretin mimetic class. Tirzepatide adds GIP receptor (GIPR) activation to GLP-1R; Retatrutide further adds glucagon receptor (GCGR) activation. The GCGR component increases hepatic glucose production suppression and — critically — energy expenditure through brown adipose tissue activation, driving higher weight loss than dual agonism alone. QSC stocks both at ≥99% HPLC with Janoshik independent COA.
All Tirzepatide effects + GCGR energy expenditure ↑, hepatic fat mobilization ↑, BAT activation
−24.2% (Phase 2 12mg, 36wk)
Phase 3 (expected ~2026-2027)
Glucagon Receptor (GCGR) — What Retatrutide Adds
The GCGR is the key mechanistic difference. Glucagon receptor activation at physiological levels (in the context of GLP-1R co-activation suppressing hyperglycemia risk) provides:
Brown adipose tissue (BAT) thermogenesis activation — energy expenditure increase beyond diet restriction
Lipolysis enhancement — direct adipose tissue fat mobilization
This energy expenditure mechanism is absent from Tirzepatide (dual only) — explains the additional ~3-5% weight loss delta
Clinical Trial Data Summary
Trial
Arms
N
Duration
Weight Reduction
Publication
SURMOUNT-1
Tirzepatide 5/10/15mg
n=2,539
72 weeks
−15.0%, −19.5%, −20.9% (vs −3.1% placebo)
Lancet 2022
Phase 2 Retatrutide
Retatrutide 1/4/8/12mg
n=338
48 weeks
−7.9%, −17.3%, −22.8%, −24.2% (vs −2.1% placebo)
NEJM 2023
Frequently Asked Questions
What is the difference between Tirzepatide and Retatrutide?
Tirzepatide: dual GLP-1R/GIPR agonist (−22.5% peak). Retatrutide: triple GLP-1R/GIPR/GCGR agonist (−24.2% peak at 36wk). GCGR addition increases energy expenditure via BAT and hepatic fat mobilization — explains higher weight loss. Direct head-to-head RCT not yet published.
Which produces more weight loss?
Phase data favors Retatrutide (−24.2% at 36wk Phase 2) vs Tirzepatide (−22.5% at 72wk Phase 3). Note: different trial durations and populations — direct comparison requires caution. Retatrutide Phase 3 data pending.
Does QSC stock both?
Yes — both at ≥99% HPLC with Janoshik COA. Research use only.
Shop GLP-1 Research Compounds at QSC
Tirzepatide · Retatrutide · Semaglutide · Cagrilintide · All ≥99% HPLC · Janoshik COA
