Survodutide and retatrutide are the two most advanced obesity drugs built around glucagon. Survodutide (Boehringer Ingelheim, licensed from Zealand Pharma) is a dual agonist: GLP-1 for appetite, plus glucagon, which is thought to act directly on the liver. [1] Retatrutide (Eli Lilly) hits GLP-1 and glucagon too — plus a third target, GIP. Both are once-weekly injections, and neither is approved.
The numbers, side by side
Different trials, populations, durations and methods — not a head-to-head. Compare like with like: "everyone who started" (treatment-regimen estimand) against the same, and "if everyone stayed on treatment" (efficacy estimand) against the same.
| Survodutide 6.0 mg — SYNCHRONIZE-1 [2] | Retatrutide 12 mg — TRIUMPH-1 | |
|---|---|---|
| Status | Investigational — no FDA filing announced | Investigational — submission planned Q1 2027 |
| Receptors | GLP-1, glucagon | GLP-1, GIP, glucagon |
| Duration | 76 weeks | 80 weeks |
| Mean weight loss (everyone who started) | 13.0% (vs 5.4% placebo) | ~25.0% [8] |
| If everyone stayed on treatment | 16.6% (vs 3.2% placebo) [3] | 28.3% [7] |
In people with type 2 diabetes (SYNCHRONIZE-2), survodutide produced up to 13.1% weight loss vs 3.1% on placebo (efficacy estimand). [5]
Tolerability is the big question
Stomach side effects are common with both drugs. Survodutide's trial stood out for how many people stopped: about 1 in 5 on the 6.0 mg dose (20.2% vs 2.9% on placebo), and 89.7% reported any GI side effect, mostly mild to moderate. [2] Separate rates for nausea, vomiting and diarrhea weren't available in the sources we could verify.
For retatrutide 12 mg in TRIUMPH-1, 11.3% stopped because of side effects (vs 4.9% on placebo), with nausea at 42.4% — plus a dysesthesia (skin sensation) signal. [8] Details: retatrutide side effects.
Survodutide's other angle: the liver
In a SYNCHRONIZE-1 MRI substudy, liver fat fell 63.1% on survodutide 6.0 mg vs 24.5% on placebo, and visceral fat fell 34.0% vs 11.8%. [4] That's why it's also in Phase 3 for MASH, a serious form of fatty liver disease (the LIVERAGE program), with FDA Breakthrough Therapy designation for MASH with fibrosis. [6]
Where each stands with the FDA
Survodutide has not been submitted to the FDA as of early October 2026. ProjectedLilly plans to submit retatrutide in Q1 2027 — company guidance, not a commitment. Follow every confirmed retatrutide milestone on the FDA approval tracker, or get an email when it changes.
More matchups: retatrutide vs CagriSema, retatrutide vs tirzepatide, retatrutide vs semaglutide, retatrutide vs weight-loss pills — or all of them on one page: retatrutide vs other weight-loss drugs.