Retatrutide is Eli Lilly's investigational once-weekly shot that targets three receptors — GLP-1, GIP and glucagon. Here's how it stacks up against every major weight-loss drug, approved or in the pipeline. Each section has a short video, the headline numbers, and a link to the full comparison with sources.
None of these are head-to-head results. Each drug was tested in its own trial with different people, doses and durations. The numbers below are the "everyone who started" average (treatment-regimen or treatment-policy estimand) at each drug's top studied dose, so they're as comparable as cross-trial numbers get — but treat the gaps as indicative only.
At a glance
| Drug | Maker | Receptors | Form | Avg. weight loss (trial) | FDA status |
|---|---|---|---|---|---|
| Retatrutide | Eli Lilly | GLP-1, GIP, glucagon | Weekly shot | ~25.0% at 80 wks (TRIUMPH-1) [2] | Investigational |
| Semaglutide (Ozempic/Wegovy) | Novo Nordisk | GLP-1 | Weekly shot | ~14.9% at 68 wks (STEP-1) [3] | Approved |
| Tirzepatide (Zepbound/Mounjaro) | Eli Lilly | GIP, GLP-1 | Weekly shot | 20.9% at 72 wks (SURMOUNT-1) [4] | Approved |
| Wegovy pill | Novo Nordisk | GLP-1 | Daily pill | 13.6% at 64 wks (OASIS 4) [5] | Approved |
| Foundayo (orforglipron) | Eli Lilly | GLP-1 | Daily pill | 11.2% at 72 wks (ATTAIN-1) [6] | Approved |
| CagriSema | Novo Nordisk | GLP-1 + amylin | Weekly shot | 20.4% at 68 wks (REDEFINE 1) [7] | Investigational |
| Survodutide | Boehringer Ingelheim | GLP-1, glucagon | Weekly shot | 13.0% at 76 wks (SYNCHRONIZE-1) [8] | Investigational |
Retatrutide vs semaglutide (Ozempic, Wegovy)
The most-asked comparison: one receptor vs three. Semaglutide 2.4 mg (the Wegovy dose) averaged about 14.9% weight loss over 68 weeks in STEP-1; retatrutide 12 mg averaged about 25% at 80 weeks in TRIUMPH-1. Semaglutide is approved, widely used and has a newer 7.2 mg dose; retatrutide is not available outside trials.
Full comparison: Retatrutide vs semaglutide →
Retatrutide vs tirzepatide (Zepbound, Mounjaro)
Both are Lilly drugs. Tirzepatide hits two receptors (GIP and GLP-1); retatrutide keeps both and adds glucagon. Tirzepatide 15 mg averaged 20.9% at 72 weeks in SURMOUNT-1. This is the only matchup with a real head-to-head coming: ProjectedTRIUMPH-5 is expected to read out around late 2026.
Full comparison: Retatrutide vs tirzepatide →
Retatrutide vs weight-loss pills (Wegovy pill, Foundayo)
Two GLP-1 pills are now approved: the Wegovy pill (13.6% at 64 weeks) and Foundayo (11.2% at 72 weeks). They skip the needle but target one receptor, and the Wegovy pill has to be taken on an empty stomach. Retatrutide has only been studied as a weekly injection.
Full comparison: Retatrutide vs weight-loss pills →
Retatrutide vs CagriSema
Novo Nordisk's next shot combines semaglutide with cagrilintide (an amylin analogue). It averaged 20.4% at 68 weeks in REDEFINE 1, but missed its goal of matching tirzepatide head-to-head in REDEFINE 4. Neither drug is approved; Novo expects an FDA decision on CagriSema in Q4 2026.
Full comparison: Retatrutide vs CagriSema →
Retatrutide vs survodutide
Boehringer Ingelheim's survodutide also uses glucagon, paired with GLP-1. It averaged 13.0% at 76 weeks (16.6% in people who stayed on treatment), about 1 in 5 people on the top dose stopped because of side effects, and it cut liver fat by about 63% in an MRI substudy. It hasn't been filed with the FDA.
Full comparison: Retatrutide vs survodutide →
The bottom line
Retatrutide's trial numbers are the largest reported so far, but they come from a drug you can't be prescribed yet. ProjectedLilly plans to submit it to the FDA in Q1 2027. If you're weighing an approved option now against waiting, read Should I wait for retatrutide? and talk to a clinician — the RetaMaps directory lists practices that prescribe approved GLP-1 medications today. For retatrutide's own data, see the TRIUMPH-1 results and side effects, or follow every milestone on the FDA approval tracker and get an email when it changes.