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Survodutide vs Retatrutide: Dual Against Triple, Both Unapproved

Survodutide (survodutide (BI 456906), Boehringer Ingelheim / Zealand Pharma) vs Retatrutide (retatrutide (LY3437943), Eli Lilly)

Last verified July 2026

By Ruth Calder · Enforcement Editor
Editorially reviewed & fact-checked against primary sources · How we verify contentLast reviewed

The verdict

⚠ Both figures are cross-trial and neither is comparable to the other: −14.9% at 46 weeks for survodutide at 4.8 mg (PMID 38330987) and −24.2% at 48 weeks for retatrutide at 12 mg (PMID 37366315). Different trials, populations and doses. The mechanistic difference is real — survodutide hits GLP-1 and glucagon, retatrutide adds GIP — and whether the third receptor is worth what it costs in tolerability is exactly what phase 3 exists to answer. Neither is approved.

Side-by-side comparison

FieldSurvodutideRetatrutide
MechanismGLP-1 / glucagon dual receptor agonist (GLP-1R + GcgR)GLP-1 / GIP / glucagon triple receptor agonist (GLP-1R + GIPR + GcgR)
Peak weight loss — phase 2−14.9% at 46 wk (4.8 mg; PMID 38330987) — cross-trial only, not comparable to retatrutide figure−24.2% at 48 wk (12 mg; PMID 37366315) — cross-trial only, not comparable to survodutide figure
Phase 3 weight-loss dataSYNCHRONIZE-1: −13.0% at 76 wk (6 mg; PMID 42253238, NEJM 2026) — publishedSURMOUNT-PLUS phase 3 ongoing; no primary results published as of mid-2026
Trial stage / statusPhase 3 complete; SYNCHRONIZE program results published 2026 (obesity + MASLD)Phase 2 complete; phase 3 (SURMOUNT-PLUS) ongoing; no phase-3 results published
MASH / liver-disease evidencePhase 2 MASH (PMID 38847460, NEJM 2024): 62% MASH resolution, 34–36% fibrosis improvement at 4.8 mg vs 14% placebo; Phase 3 MASLD (PMID 42252333, Nature Medicine 2026): 84.2% achieved ≥30% liver fat reduction vs 24.3% placeboNo dedicated MASH or liver-fat clinical trial published; liver-related secondary outcomes not reported in phase-2 obesity paper
AdministrationOnce-weekly subcutaneous injectionOnce-weekly subcutaneous injection
FDA approval statusNot FDA-approved; investigational (US)Not FDA-approved; investigational (US)
Key differentiatorMost robust MASH / liver-disease evidence of any investigational obesity drug to date; phase 3 publishedHighest published phase-2 obesity weight-loss magnitude; triple agonism adds GIP component absent in survodutide

Frequently asked questions

Which works better for weight loss, Survodutide or Retatrutide?

Survodutide recorded −14.9% at 46 wk (4.8 mg; PMID 38330987) — cross-trial only, not comparable to retatrutide figure; Retatrutide recorded −24.2% at 48 wk (12 mg; PMID 37366315) — cross-trial only, not comparable to survodutide figure. ⚠ These come from separate trials with different protocols and populations, so the gap between two numbers from two studies is weaker evidence than it looks. No head-to-head trial of this pair is on record here.

Are Survodutide and Retatrutide the same drug?

No. Survodutide is survodutide (BI 456906) and Retatrutide is retatrutide (LY3437943) — different molecules, and they work differently: GLP-1 / glucagon dual receptor agonist (GLP-1R + GcgR) against GLP-1 / GIP / glucagon triple receptor agonist (GLP-1R + GIPR + GcgR). Results with one do not predict results with the other.

How is each one taken?

Survodutide: Once-weekly subcutaneous injection. Retatrutide: Once-weekly subcutaneous injection. Worth weighing honestly against your own habits — the best drug for you is partly the one you will still be taking in eight months, and a dosing routine that does not fit a life gets abandoned.

Can I switch from Survodutide to Retatrutide?

Yes, with a prescriber. Expect to re-titrate from the bottom of the new drug's ladder rather than starting where you left off: these are different molecules and tolerance to one does not transfer to the other. Both the old drug's washout and the new drug's schedule apply.

Which one should I ask for?

That is a prescriber's call, and anyone answering it from a table is guessing. What a page like this can do is tell you what the trials measured, what the manufacturers charge, and where the evidence is still missing, so the conversation starts from the record rather than from an advertisement.

References

  1. 1.Jastreboff AM, Karol A, Stefanski A, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity - A Phase 2 Trial New England Journal of Medicine. 2023. PMID: 37366315.
  2. 2.le Roux CW, Steen O, Lucas KJ, et al. Glucagon and GLP-1 receptor dual agonist survodutide for obesity: a randomised, double-blind, placebo-controlled, dose-finding phase 2 trial Lancet Diabetes & Endocrinology. 2024. PMID: 38330987.
  3. 3.Sanyal AJ, Bedossa P, Fraessdorf M, et al. A Phase 2 Randomized Trial of Survodutide in MASH and Fibrosis New England Journal of Medicine. 2024. PMID: 38847460.
  4. 4.le Roux CW, Wharton S, Startseva E, et al. Survodutide Once Weekly for the Treatment of Adults with Obesity New England Journal of Medicine. 2026. PMID: 42253238.
  5. 5.Kaplan LM, Startseva E, le Roux CW, et al. Survodutide in adults with obesity and metabolic dysfunction-associated steatotic liver disease: SYNCHRONIZE-MASLD, a randomized, double-blind, placebo-controlled phase 3 trial Nature Medicine. 2026. PMID: 42252333.
  6. 6.Lawitz EJ, Fraessdorf M, Neff GW, et al. Efficacy, tolerability and pharmacokinetics of survodutide, a glucagon/glucagon-like peptide-1 receptor dual agonist, in cirrhosis Journal of Hepatology. 2024. PMID: 38857788.

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