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Survodutide vs Retatrutide (2026): A Head-to-Head Look at Two Pipeline Obesity Drugs

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

Last verified 2026-07-06

By Eli Marsden · Founding Editor
Editorially reviewed (not clinically reviewed) · How we verify contentLast reviewed

The verdict

Survodutide and retatrutide are both investigational drugs that have not been approved by the FDA; all data comes from separate phase-2 and phase-3 trials with different designs, populations, and durations, and no head-to-head comparison exists. In their respective phase-2 trials, retatrutide achieved −24.2% body weight loss at 48 weeks (12 mg dose, NEJM 2023), while survodutide reached −14.9% at 46 weeks (4.8 mg dose, Lancet Diabetes Endocrinol 2024) — but these figures are not directly comparable across trials. Survodutide is the only one of the two with published phase-3 results (SYNCHRONIZE-1, NEJM 2026: −13.0% at 76 weeks) and a dedicated MASH liver-disease program (SYNCHRONIZE-MASLD, Nature Medicine 2026), giving it a meaningful edge for patients with metabolic-associated fatty liver disease. Retatrutide's triple mechanism (GLP-1/GIP/glucagon) is mechanistically broader than survodutide's dual (GLP-1/glucagon), and its phase-3 SURMOUNT-PLUS program is ongoing but no primary results have been published as of mid-2026. Neither drug should be directly ranked from cross-trial data, and availability for either will depend on regulatory approval that has not yet occurred in the United States.

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

Is retatrutide stronger than survodutide for weight loss?

Retatrutide showed −24.2% body weight loss in its phase-2 trial (NEJM 2023, 48 weeks, 12 mg), while survodutide showed −14.9% in its phase-2 trial (Lancet Diabetes Endocrinol 2024, 46 weeks, 4.8 mg). However, these trials had different designs, populations, doses, and endpoints, so the numbers are not directly comparable — no head-to-head trial exists. Retatrutide's phase-3 results are not yet published.

What is survodutide's main advantage over retatrutide?

Survodutide has the most extensive published liver-disease (MASH/MASLD) data of any investigational obesity drug. Its phase-2 MASH trial (NEJM 2024) showed 62% of patients achieved MASH resolution, and its phase-3 SYNCHRONIZE-MASLD trial (Nature Medicine 2026) showed 84.2% of survodutide patients achieved ≥30% liver fat reduction versus 24.3% on placebo. Retatrutide has no dedicated published liver/MASH trial.

How do survodutide and retatrutide differ mechanistically?

Survodutide is a GLP-1/glucagon dual receptor agonist, activating two receptors: GLP-1R (appetite/satiety) and GcgR (energy expenditure, liver fat reduction). Retatrutide is a triple agonist that additionally targets the GIP receptor (GIPR), which may contribute to its higher weight-loss magnitude in phase-2 data, though the clinical significance of the added GIPR agonism over a dual agent is not established from head-to-head data.

When might survodutide or retatrutide receive FDA approval?

Neither has been approved by the FDA as of mid-2026. Survodutide's phase-3 SYNCHRONIZE-1 obesity trial published primary results in NEJM 2026, which could support an NDA filing; the SYNCHRONIZE-MASLD trial for liver disease also published in 2026. Retatrutide's SURMOUNT-PLUS phase-3 program is ongoing with no results published yet. Both face regulatory review timelines that are not publicly confirmed.

Can you directly compare survodutide vs retatrutide weight-loss data?

No. All available comparisons are cross-trial only. The phase-2 trials differed in dose ranges, patient selection, trial duration, and endpoints. Cross-trial weight-loss numbers should not be used to conclude that one drug is definitively more effective than the other. Only a randomized head-to-head trial could establish comparative efficacy.

Is survodutide or retatrutide available to patients now?

Neither survodutide nor retatrutide is available outside of clinical trials as of mid-2026. Both are investigational in the United States and have not received FDA approval. Patients interested in access would need to enroll in an ongoing clinical trial through ClinicalTrials.gov.

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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