# Retatrutide vs Tirzepatide vs Semaglutide: Head-to-Head Trial Numbers

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Retatrutide Statistics 2026 · 2026-03-23


    TL;DR: Retatrutide vs Tirzepatide vs Semaglutide: Head-to-Head Trial Numbers. Headline figure: Retatrutide 12 mg, 48 wk: ~24% body weight reduction (Phase 2).



Key Statistics



  Retatrutide 12 mg, 48 wk: ~24% body weight reduction (Phase 2).


  Tirzepatide 15 mg, 72 wk (SURMOUNT-1): ~22.5% body weight reduction.


  Semaglutide 2.4 mg, 68 wk (STEP 1): ~14.9% body weight reduction.


  Cross-trial comparisons are indirect and not formally controlled.




Background


Retatrutide is Eli Lilly's investigational triple agonist of the GLP-1, GIP, and glucagon receptors. Phase 2 data published in the New England Journal of Medicine in 2023 reported some of the largest weight-loss effects ever recorded for an injectable obesity therapeutic. The figures above summarize what is publicly available as of Q1 2026 from the Phase 2 program, secondary analyses, and the TRIUMPH Phase 3 program in progress.



What the Numbers Mean


Efficacy ceiling


The 12 mg arm has not produced a clear plateau on the dose-response curve through 48 weeks, suggesting either higher doses or longer durations could push mean weight loss further.


Tolerability profile


Discontinuation rates in the 6–16% range are broadly consistent with other incretin-class drugs, although nausea and GI events appear at higher absolute rates than with semaglutide.


Comparator context


Until TRIUMPH head-to-head data lands, all comparisons against tirzepatide and semaglutide remain indirect and should be interpreted cautiously.



Implications for Researchers


For laboratories tracking GLP-class development, the combination of high efficacy, an unclear dose ceiling, and rapidly expanding press coverage make retatrutide one of the most-watched compounds of 2026. Demand on the research-chemical side has tracked the clinical signal closely, with vendor SKU counts and consumer search interest rising in parallel with each major data readout.



Sources & Methodology


Figures cited above are drawn from a mix of publicly reported data through Q1 2026, including FDA enforcement records, Eli Lilly investor disclosures, telehealth company filings, and aggregated peptide-supplier price tracking by this site. Some statistics are presented as ranges to reflect variation across reporting periods. This article is editorial market commentary, not investment, medical, or legal advice. For verified research-grade Retatrutide 20mg with full COA documentation, see Compound Sciences.

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