The Definitive Peptide Research Reference Guide — Compound Review

Home Compounds BPC-157 TB-500 CJC-1295 Ipamorelin GLP-1 GHK-Cu Epithalon NAD+ Comparisons BPC-157 vs TB-500 Sermorelin vs Ipamorelin Semaglutide vs Tirzepatide Guides GHK-Cu Guide GHRH Analogues Ipamorelin Guide Semaglutide Dosage BPC-157 Dosage Research Guides Joint Pain Weight Loss Longevity Shop Purgo Labs

Semaglutide vs Tirzepatide vs Retatrutide

Three-way GLP-1 class comparison: Semaglutide, Tirzepatide, and Retatrutide — from pure GLP-1 agonism to dual GLP-1/GIP to triple GLP-1/GIP/glucagon agonism. Each step adds a receptor mechanism and increases weight loss.

Weight Loss Comparison

Semaglutide (STEP-1): 14.9% at 68 weeks. Tirzepatide (SURMOUNT-1): 20.9% at 72 weeks. Retatrutide (TRIUMPH-1): 24.2% at 48 weeks. Each additional receptor mechanism adds approximately 5–6 percentage points of weight loss.

Mechanism Progression

Semaglutide: GLP-1 only — appetite suppression, insulin secretion, gastric emptying. Tirzepatide: + GIP — enhanced insulin sensitivity in adipose tissue. Retatrutide: + glucagon — increased energy expenditure and hepatic fat reduction.

Regulatory Status

Semaglutide: FDA-approved (Ozempic, Wegovy). Tirzepatide: FDA-approved (Mounjaro, Zepbound). Retatrutide: Phase 3, not yet approved. For approved compounds only, tirzepatide is the most effective option currently available.