Tirzepatide vs retatrutide
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 | Tirzepatide | Retatrutide (investigational) | Source |
|---|---|---|---|
| Regulatory status | FDA-approved: Mounjaro (2022) and Zepbound (2023) | Investigational; not a component of any FDA-approved drug; cannot be used in compounding under federal law | source |
| Mechanism | Dual agonist: GIP + GLP-1 receptors | Triple agonist: GIP + GLP-1 + glucagon receptors | source |
| Best published weight result | -20.9% at 72 weeks, 15 mg, phase 3, n=2,539 (SURMOUNT-1) | -24.2% at 48 weeks, 12 mg, phase 2, n=338 | source |
| Safety evidence | FDA label from 13,000+ trial patients plus postmarketing data; completed 13,299-patient CV outcomes trial | Phase 2 safety only: GI events dose-related; dose-dependent heart-rate increases peaking at week 24 | source |
| Cardiovascular outcomes data | SURPASS-CVOT complete and published (noninferior to dulaglutide) | TRIUMPH-Outcomes (about 10,000 adults) running to about 2029 | source |
| How you can get it | Prescription products at licensed pharmacies | Only inside clinical trials; FDA has warned telehealth sellers and distributors marketing it | source |
This is an approved drug versus an experiment in progress. Tirzepatide has two FDA-approved products and a completed cardiovascular outcomes trial. Retatrutide, a triple agonist (GIP, GLP-1, glucagon), posted a striking 24.2% mean weight reduction at 48 weeks in phase 2, but it has no approved product, phase 3 results are pending, and FDA states it cannot legally be compounded.
The 24.2% phase 2 figure for retatrutide comes from 338 participants over 48 weeks and cannot be compared directly to tirzepatide's 72-week phase 3 data. Phase 3 programs exist because phase 2 effect sizes often shrink. Anything sold online as 'retatrutide' is an unapproved research chemical: FDA states it is not a component of any approved drug and cannot legally be compounded.