Retatrutide vs tirzepatide vs semaglutide
Every row cites its source. Where a cell reflects our own reading of the evidence rather than an external source, the row says so.
| Dimension | Retatrutide | Retatrutide Stage | Tirzepatide | Tirzepatide Stage | Semaglutide | Semaglutide Stage | Source |
|---|---|---|---|---|---|---|---|
| Mechanism | Triple agonist: GIP + GLP-1 + glucagon receptors | Published pharmacology | Dual agonist: GIP + GLP-1 receptors | FDA-labeled | Selective GLP-1 receptor agonist | FDA-labeled | source |
| Regulatory status | Investigational; zero Drugs@FDA records; cannot be used in compounding under federal law | Phase 3 ongoing | FDA-approved: Mounjaro (2022), Zepbound (2023) | Approved | FDA-approved: Ozempic, Wegovy (incl. cardiovascular risk-reduction indication) | Approved | source |
| Best published mean weight loss | -24.2% at 48 weeks, 12 mg, n=338 | Phase 2 | -20.9% at 72 weeks, 15 mg, n=2,539 (SURMOUNT-1) | Phase 3 | -14.9% at 68 weeks, 2.4 mg, n=1,961 (STEP 1) | Phase 3 | source |
| Type 2 diabetes glycemic data | HbA1c -1.94 points at 40 weeks (12 mg) vs placebo, monotherapy | Phase 3 (published June 2026) | HbA1c reductions superior to semaglutide 1 mg in SURPASS-2 (per our sister site's cited table) | Phase 3 | Established glycemic efficacy across the SUSTAIN program (see label) | Approved label | source |
| Cardiovascular outcomes evidence | None yet: TRIUMPH-Outcomes (about 10,000 adults) runs to about 2029 | Phase 3 ongoing | Noninferior to dulaglutide in T2D (SURPASS-CVOT, per our sister site's cited table) | Phase 3 (completed) | SELECT: MACE hazard ratio 0.80 vs placebo in 17,604 patients; approved CV indication | Phase 3 (completed) | source |
| Most common adverse events | GI events, dose-related, mostly mild to moderate; dose-dependent heart-rate increases peaking at week 24 | Phase 2 safety only (plus one phase 3 T2D trial) | GI-led; label lists rates from pooled phase 3 trials | FDA-labeled | GI-led; label lists rates from pooled phase 3 trials | FDA-labeled | source |
| Long-term and stopping data | Longest published randomized exposure 48 weeks; no published stopping data (maintenance trial reads out ~2028) | Phase 2 / registry | Multi-year randomized data and a completed CV outcomes trial (see sister site) | Phase 3 / label | Multi-year randomized data incl. SELECT (mean 39.8 months exposure) | Phase 3 / label | source |
| How you can lawfully get it | Clinical trials or sponsor expanded access only; FDA has warned telehealth sellers and distributors | Investigational | Prescription products at licensed pharmacies | Approved | Prescription products at licensed pharmacies | Approved | source |
| Head-to-head evidence | vs tirzepatide: TRIUMPH-5 underway, estimated primary completion Nov 2026; vs semaglutide (T2D): trial estimated Aug 2026; no results from either | Phase 3 ongoing | Beat semaglutide 2.4 mg head-to-head in obesity (SURMOUNT-5, per our sister site's cited table) | Phase 3 (completed) | Holds the only completed placebo-controlled CV outcomes win in obesity (SELECT) | Phase 3 (completed) | source |
Researching Retatrutide vs tirzepatide vs semaglutide itself? Its dedicated guide site is at tirzrx.com.