Overview
Mazdutide (IBI362, LY3305677) is a once-weekly dual GLP-1 receptor and glucagon receptor agonist developed by Innovent Biologics in partnership with Eli Lilly, modeled on mammalian oxyntomodulin. It became the world's first GLP-1/glucagon dual receptor agonist approved for weight management when China approved it in June 2025 (marketed as Xinermei). Phase 2 trials in Chinese adults showed up to 14.8% weight loss at 48 weeks and up to 80% reduction in liver fat in some cohorts.
Mechanism of action
Mazdutide is a long-acting analogue of oxyntomodulin (OXM), the gut-derived peptide that naturally activates both GLP-1 and glucagon receptors. GLP-1 receptor agonism drives glucose-dependent insulin secretion, suppresses glucagon, slows gastric emptying, and reduces appetite through central hypothalamic signaling — producing the caloric restriction typical of GLP-1 agents. The added glucagon receptor (GCGR) activation increases hepatic fatty acid oxidation and stimulates energy expenditure, directly clearing hepatic lipid accumulation and improving metabolic dysfunction-associated steatotic liver disease (MASLD). GCGR agonism also increases FGF21 secretion, which enhances thermogenesis and peripheral insulin sensitivity. The combination results in weight loss driven by both reduced caloric intake and increased energy expenditure, with pronounced hepatic fat reduction that distinguishes dual agonists from GLP-1-only agents.
Dosing protocols
| Purpose | Route | Dosage | Frequency | Notes |
|---|---|---|---|---|
| Obesity / weight management (clinical trials) | subcutaneous | 3–6 mg | Once weekly | Phase 2 most effective dose: 6 mg weekly. Titrated upward from lower doses. Once-weekly administration. |
Dosing information is for educational purposes only. Consult a qualified healthcare professional before using any peptide.
Research summary
Phase 1b trials in Chinese adults with obesity confirmed tolerability up to 9-10 mg. Phase 2 trials in overweight/obese Chinese adults showed 12% weight loss at 4 mg and 14.8% at 6 mg at 48 weeks vs 0.5% placebo. Liver fat was reduced by up to 80% in some cohorts. Phase 2 T2D data showed significant HbA1c reductions published in Diabetes Care. Phase 3 in China showed clinically meaningful weight loss in Chinese adults with obesity (data May 2025). Approved in China June 2025 for weight management and September 2025 for T2D. US Phase 2 trials ongoing (~179 participants).
Side effects
Side effects vary by individual. This is not an exhaustive list. Report unusual symptoms to a healthcare professional.
Common stacks
Peptides commonly paired with Mazdutide for synergistic effects.
Legal status
Approved in China as Xinermei for obesity (June 2025) and type 2 diabetes (September 2025). Not approved by the FDA. In Phase 2 development in the United States. Not available outside China or authorized clinical trials. No research chemical or compounding pathway.
Where to get it
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