Mazdutide (also identified as IBI362 and LY3305677) was approved by China's NMPA in June 2025 for chronic weight management and in September 2025 for glycemic control in type 2 diabetes. It holds no FDA or EMA authorisation. This page describes what its trials measured; it is educational, not a recommendation.
Overview
The benefit mazdutide has actually demonstrated, in randomised phase 3 trials, is substantial body-weight reduction — between 11% and 16.7% depending on dose and trial duration — alongside improvements in glycemic control in adults with type 2 diabetes. Those are the two indications it holds approval for in China, and both rest on published, placebo-controlled data rather than on inference from the drug class.
Mazdutide is an oxyntomodulin analogue that activates two receptors: GLP-1 and glucagon. The GLP-1 arm suppresses appetite and lowers glucose in the familiar incretin way. The glucagon arm is the differentiator, and the reason the compound is discussed separately from semaglutide-class drugs at all.
Weight reduction, with the numbers
Two placebo-controlled phase 3 trials define the weight endpoint, and they used different doses.
In GLORY-1 (NEJM 2025; PMID 40421736), 610 Chinese adults with a BMI of at least 28 — or 24 to under 28 with a weight-related condition — received 4 mg or 6 mg weekly or placebo for 48 weeks. Mean weight change at week 48 was −11.00% (4 mg) and −14.01% (6 mg), against +0.30% on placebo. Notably, 35.7% and 49.5% of participants respectively lost at least 15% of body weight, versus 2.0% on placebo.
GLORY-2 (JAMA 2026; PMID 42251595) pushed the dose to 9 mg weekly in 461 adults with a BMI of at least 30 over 60 weeks, reporting −16.65% versus −1.50% on placebo, with 84.3% versus 33.1% reaching at least 5% reduction.
Both trials used a treatment-policy estimand, which counts participants regardless of whether they stopped the drug early — a conservative choice that makes the effect sizes harder to inflate.
Glucose and cardiometabolic endpoints
Mazdutide's second approved indication rests on separate phase 3 work in Chinese adults with type 2 diabetes, published in Nature in 2026 against placebo (PMID 41407859) and against the established GLP-1 agonist dulaglutide (PMID 41407860). The active-comparator trial is the more demanding test, since beating placebo and beating a marketed drug are different bars.
GLORY-1 also reported favourable movement across its prespecified cardiometabolic measures — blood pressure, lipids, and waist circumference among them. Those are secondary endpoints, not outcome data: no completed trial has yet shown that mazdutide reduces heart attacks or strokes, as has been demonstrated for some single GLP-1 agonists.
What the glucagon arm is meant to add
Glucagon receptor agonism is hypothesised to raise energy expenditure and mobilise fat stored in the liver — an output-side effect layered onto GLP-1's intake-side effect. In principle that could produce more weight loss per unit of appetite suppression, and could matter for fatty liver disease.
The tension is that glucagon on its own raises blood glucose, which is exactly what a diabetes drug must not do. Getting the receptor balance right is the central pharmacological problem of this whole drug subclass, and it is why the glycemic trials above matter more than they would for a pure GLP-1 agent.
How mazdutide compares
- Survodutide — the other prominent GLP-1/glucagon dual agonist, developed by Boehringer Ingelheim and studied heavily in metabolic liver disease. Investigational everywhere.
- Tirzepatide — dual agonist too, but the second receptor is GIP, not glucagon. Different biology, different approval footprint.
- Semaglutide — a single GLP-1 receptor agonist, and the reference point most cross-trial comparisons implicitly use.
No published head-to-head trial pits mazdutide against semaglutide or tirzepatide. Comparing percentage figures across trials that differ in population, baseline BMI, duration, and estimand is unreliable, and the mazdutide trials enrolled Chinese adults exclusively.
Evidence and caveats
- Approval in China is not approval elsewhere; there is no FDA or EMA authorisation.
- Every pivotal trial enrolled Chinese adults at Chinese sites, so effect estimates may not transfer directly to other populations.
- The longest published trial ran 60 weeks — short relative to how obesity pharmacotherapy is actually used.
- Gastrointestinal adverse events were common and dose-related; benefit and tolerability are read together, not separately.
- Material sold as "mazdutide" outside a pharmacy supply chain is not the manufactured product these trials evaluated.