Mazdutide
Aliases: IBI362 · LY3305677 · Xinermei
Last verified: 2026-09-24
The short version
Mazdutide is historically the first approved GLP-1/glucagon dual agonist in the world (China, June 2025) — and the best example of the new dynamic: a drug that exists in only one country while the gray market sells it globally as a 'research chemical' beyond the Lilly/Innovent patent. Scientifically it is a legitimate story: GLORY-1 is a solid NEJM paper, and the liver component (up to 80% liver-fat reduction) is a genuine differentiator. But 'mazdutide' from a vial is — as with eloralintide — a GMP-regulated product inside trials, not a free-market chemical; and the FDA already sent warning letters to sellers in 2026. This is a drug, not a peptide for experimenting.
Identity & type
- Molecular type
- analog
- Origin
- An oxyntomodulin analog: human oxyntomodulin with amino-acid substitutions for GCGR strengthening and lipid conjugation for a ~1-week half-life.
Mechanism of action
A once-weekly peptide dual agonist of the GLP-1 and glucagon receptors (based on the oxyntomodulin scaffold); the GLP-1 component reduces appetite and glucose, the glucagon component increases energy expenditure and — per phase 3 data — strongly reduces liver fat; balanced activation is designed to avoid glucagon-mediated hyperglycemia.
Dosing & routes
Official / clinical context
NMPA approval (Jun 2025, Sep 2025); Chinese Xinermei prescribing information; NEJM GLORY-1 publication (PMID 40421736).
Regulator-approved labeling and published study designs — never a recommendation.
Community-reported practice
The community doses from press releases: 1–10 mg SC weekly with escalation, with mixed stories of 'competing with retatrutide'. A gray product cannot be the approved drug — the identity question here is regulatory, not just safety.
Unverified self-reports. Not medical advice. Not endorsement.
Protocol — official vs community
Official / label
Investigational GLP-1/glucagon dual agonist (Lilly, licensed in China). Phase 3: SC weekly to 4 or 6 mg.
- 01Titration steps of 2 mg every ≥4 weeks
- 02Maintenance: 4 or 6 mg weekly
Duration: Trial-defined.
Phase 3 results (~18–19% mean loss) place it below retatrutide and around tirzepatide territory.
Community (anecdotal)
Appears in gray-market channels from Chinese supply; unvalidated.
- Cycle:
- Unknown.
- Break:
- Unknown.
Same investigational-drug caveats as retatrutide apply.
Human evidence
Strong for approved indications in the Chinese population: phase 3 GLORY-1 (n=610) published in NEJM; GLORY-2 and DREAMS-3 follow. Caveat: nearly all key data come from Chinese cohorts — generalizability to European/American populations is an open (but reasonable) question.
Preclinical evidence
Standard package for the incretin class; mice show increased energy expenditure and weight loss in both receptor knock-out contexts.
Known risks
- GI intolerance (class)characterized
- Class signals: gallstones, pancreatitis, retinopathy with rapid glucose correctioncharacterized
- Counterfeiting/unapproved status of gray vialscharacterized
Teal: characterized in clinical/labeling contexts. Amber: theoretical or reported outside controlled settings.
Unknowns & evidence gaps
- Generalizability of Chinese phase 3 to other populations
- Cardiovascular outcome trials (the class requires them)
- Long-term safety of 9+ mg doses
Frequently asked questions
References
- Ji L et al. Once-Weekly Mazdutide in Chinese Adults with Obesity or Overweight (GLORY-1). NEJM, 2025 (PMID 40421736)
- Mazdutide: First Approval. Drugs, 2025
- Innovent Biologics — NMPA approval press releases (Jun/Sep 2025)
- FDA warning letter re: mazdutide sales (2026)