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Mazdutide vs Retatrutide (2026): Pipeline GLP-1 Drugs Compared

Mazdutide (mazdutide (IBI362 / LY3305677), Innovent Biologics / Eli Lilly) 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

Mazdutide and retatrutide are both investigational obesity drugs that have not received FDA approval in the United States; all comparisons are cross-trial only, as no head-to-head study between them exists. Mazdutide (co-developed by Innovent Biologics and Eli Lilly) is a GLP-1/glucagon dual agonist that has completed phase-3 trials primarily in Chinese populations — GLORY-1 (NEJM 2025) showed −12.55% body weight at 32 weeks with 6 mg, and GLORY-2 (JAMA 2026) evaluated a 9 mg dose — with potential regulatory consideration in China; however, it remains investigational for the US market. Retatrutide (Eli Lilly) adds GIP receptor agonism to form a triple agonist and achieved −24.2% weight loss in its phase-2 trial (NEJM 2023, 12 mg, 48 weeks), though its phase-3 SURMOUNT-PLUS program results have not been published as of mid-2026. The larger phase-2 weight-loss figure for retatrutide versus mazdutide cannot be used to declare a clinical winner because the trials used different populations (global vs. predominantly Chinese), dose escalation schedules, durations, and endpoints. Neither drug has liver-disease-specific published phase-3 data comparable to survodutide's MASH program. Patients should not expect access to either drug outside of clinical trials in the US.

Side-by-side comparison

FieldMazdutideRetatrutide
MechanismGLP-1 / glucagon dual receptor agonist (GLP-1R + GcgR)GLP-1 / GIP / glucagon triple receptor agonist (GLP-1R + GIPR + GcgR)
Phase 2 peak weight loss−11.3% at 24 wk (6 mg; PMID 38092790, Nature Communications 2023) — cross-trial, 24-wk endpoint vs retatrutide's 48-wk endpoint; not directly comparable−24.2% at 48 wk (12 mg; PMID 37366315, NEJM 2023) — cross-trial, not directly comparable to mazdutide figure
Phase 3 weight-loss dataGLORY-1 (PMID 40421736, NEJM 2025): −12.55% at 32 wk (6 mg) in Chinese adults; GLORY-2 (PMID 42251595, JAMA 2026): 9 mg dose evaluated in Chinese adultsSURMOUNT-PLUS phase 3 ongoing; no primary results published as of mid-2026
Trial stage / statusPhase 3 complete (GLORY-1 2025, GLORY-2 2026); conducted primarily in China; US regulatory status: investigationalPhase 2 complete; phase 3 (SURMOUNT-PLUS) ongoing globally; no phase-3 results published
Geographic scope / regulatory statusPhase 3 trials conducted in China; regulatory filing in China (NMPA) in progress; not FDA-approved for US marketGlobal phase-3 program; not FDA-approved
MASH / liver-disease evidenceNo dedicated MASH or liver-disease clinical trial publishedNo dedicated MASH or liver-disease clinical trial published
AdministrationOnce-weekly subcutaneous injectionOnce-weekly subcutaneous injection
FDA approval statusNot FDA-approved; investigational (US)Not FDA-approved; investigational (US)

Frequently asked questions

Is retatrutide or mazdutide more effective for weight loss?

No direct comparison exists. Retatrutide's phase-2 trial (NEJM 2023) reported −24.2% body weight loss at 48 weeks (12 mg), while mazdutide's GLORY-1 phase-3 trial (NEJM 2025) in Chinese adults showed −12.55% at 32 weeks (6 mg). These numbers come from trials with different designs, populations, durations, and dose levels — they cannot be used to rank one drug over the other without a head-to-head study.

How does mazdutide's dual mechanism compare to retatrutide's triple mechanism?

Mazdutide activates two receptors: GLP-1R (appetite suppression, insulin secretion) and GcgR (energy expenditure, liver fat). Retatrutide adds a third: GIPR (glucose-dependent insulin potentiation, adipose tissue signaling). Whether the added GIP agonism translates into meaningfully greater weight loss or metabolic benefit in practice is not established from cross-trial data, and no head-to-head study between these two drugs has been published.

Why are mazdutide's trials conducted mainly in China?

Mazdutide was developed primarily by Innovent Biologics, a Chinese biopharmaceutical company, in partnership with Eli Lilly. The GLORY-1 and GLORY-2 phase-3 trials enrolled Chinese adults with obesity. This means the evidence base reflects a Chinese population and body-composition context, and the results may not generalize directly to Western populations. The drug has been submitted for regulatory review in China but is not FDA-approved.

Is mazdutide approved anywhere in the world?

As of mid-2026, mazdutide has completed phase-3 trials in China (GLORY-1, NEJM 2025; GLORY-2, JAMA 2026) and a regulatory filing with China's NMPA has been reported. It is not FDA-approved in the United States and is not commercially available in Western markets.

When could retatrutide or mazdutide be available in the US?

Neither is available outside clinical trials in the US as of mid-2026. Retatrutide's phase-3 SURMOUNT-PLUS trial is ongoing with no primary results published. Mazdutide's phase-3 evidence is from China-based trials; a US/global development program would require additional regulatory engagement. Timelines for FDA review for either drug have not been publicly confirmed.

Do mazdutide and retatrutide share any connection to Eli Lilly?

Yes — both drugs have an Eli Lilly connection. Mazdutide (IBI362 / LY3305677) was co-developed with Innovent Biologics under a license from Lilly. Retatrutide (LY3437943) is a wholly Lilly-developed asset. They are distinct molecular entities in separate development programs and are not interchangeable.

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.Ji L, Jiang H, Cheng Z, et al. A phase 2 randomised controlled trial of mazdutide in Chinese overweight adults or adults with obesity Nature Communications. 2023. PMID: 38092790.
  3. 3.Ji L, Jiang H, Bi Y, et al. Once-Weekly Mazdutide in Chinese Adults with Obesity or Overweight New England Journal of Medicine. 2025. PMID: 40421736.
  4. 4.Gao L, Jiang H, Cai H, et al. Treatment With 9-mg Mazdutide for Weight Reduction in Chinese Adults With Obesity: The GLORY-2 Randomized Clinical Trial JAMA. 2026. PMID: 42251595.
  5. 5.Gadde KM, Talebloo J, Heymsfield SB, et al. Mazdutide and Orforglipron — New Evidence in Obesity and Diabetes JAMA. 2026. PMID: 42251768.
  6. 6.Ji L, et al. Mazdutide 9 mg in Chinese adults with a body mass index ≥30 kg/m² but without diabetes Med (New York). 2026. PMID: 41875890.

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