Weekly GLP-1 and glucagon dual agonist, approved in China in 2025 for weight management and type 2 diabetes; not approved in the US.
Also called IBI362, LY3305677, Xinermei (China brand name)
Mazdutide is a once-weekly injectable peptide modeled on oxyntomodulin, a gut hormone that naturally switches on both the GLP-1 receptor and the glucagon receptor. Eli Lilly discovered it and licensed China rights to Innovent Biologics. In June 2025 China's regulator approved it for long-term weight management, and in September 2025 for blood sugar control in type 2 diabetes. It is the first approved drug of the GLP-1 plus glucagon type. It is not approved by the FDA or EMA.
The approval rests on GLORY-1, a phase 3 trial of 610 Chinese adults. At 48 weeks, weight fell 11.0% on 4 mg and 14.0% on 6 mg, while placebo stayed flat (+0.3%). Half of people on 6 mg lost at least 15% of their body weight. A higher 9 mg dose in GLORY-2 produced 16.7% loss at 60 weeks versus 1.5% on placebo, with more vomiting and nausea.
Outside China the evidence is thinner. A US phase 2 trial run by Lilly in 179 adults found 15.6% (10 mg) and 18.1% (16 mg) weight loss at 32 weeks among people who stayed on treatment (efficacy estimand), but 20% of people on 16 mg quit because of side effects. No Lilly phase 3 trial was registered on ClinicalTrials.gov when we checked in October 2026, so US availability is years away if it comes at all.
What it binds to, and what happens inside the body after that, step by step.
Mazdutide activates the GLP-1 receptor and the glucagon receptor. The GLP-1 side reduces appetite, slows the stomach and improves insulin release after meals. The glucagon side acts mostly on the liver and raises energy expenditure and fat burning, which is the proposed reason for its larger effect on liver fat and waist size than GLP-1 drugs alone.
Human results and animal results are kept apart below. A result in rats tells you a mechanism is plausible. It does not tell you what happens in a person.
Mazdutide has several phase 3 randomized trials, almost all in Chinese adults, showing 11% to 17% weight loss and strong blood sugar control, plus a US phase 2 trial with similar or larger losses at higher doses. The gaps are non-Chinese phase 3 data, cardiovascular outcome data, safety beyond about 60 weeks, and a head-to-head obesity trial against semaglutide 2.4 mg or tirzepatide.
610 Chinese adults with BMI 28 or higher, or 24 or higher with a comorbidity, 48 weeks
Weight fell 11.0% (4 mg) and 14.0% (6 mg) versus +0.3% on placebo at 48 weeks; 49.5% on 6 mg lost at least 15%.
Read the study461 Chinese adults with BMI 30 or higher, 60 weeks
Weight fell 16.7% versus 1.5% on placebo; vomiting 53% versus 1%, nausea 47% versus 3%.
Read the study179 US adults with obesity or overweight, no diabetes, 48 weeks
At 32 weeks weight fell 7.3% (3 mg phase), 15.6% (10 mg) and 18.1% (16 mg) versus 0.9% on placebo (efficacy estimand); 20% stopped 16 mg for side effects.
Read the study320 Chinese adults with type 2 diabetes on diet and exercise alone, 24 weeks
HbA1c fell 1.57 (4 mg) and 2.15 points (6 mg) versus 0.14 on placebo; weight fell 5.6% and 7.8%.
Read the study731 Chinese adults with type 2 diabetes on oral drugs, 28 weeks
Beat dulaglutide 1.5 mg on HbA1c by 0.24 to 0.30 points and on weight by 3.8 to 5.8 percentage points.
Read the study248 Chinese adults, 24 weeks
Weight fell 6.7% to 11.3% across 3 to 6 mg versus +1.0% on placebo.
Read the study32 US adults with overweight or obesity, 20 weeks
Weight fell 20% to 21% at 20 weeks versus 0.1% on placebo, in a very small sample.
Read the studyNo preclinical studies are listed as key studies here. The human data above carries the evidence.
These are questions the published research has not answered.
China NMPA approved the 4 mg and 6 mg program for weight management in June 2025 and for type 2 diabetes in September 2025. A supplementary application for the 9 mg dose was accepted for review in November 2025; we could not confirm an approval decision. Lilly holds rights outside China; its US phase 2 is complete and no phase 3 was registered as of October 2026. WADA: not named on the 2026 Prohibited List, and because it holds a government approval (China) it does not fall under S0.
No human half-life has been published for Mazdutide, so we do not draw a clearance curve. Half-lives quoted online for it are usually estimates from animal data.
This table records the doses that trials and approved labels used, with the source for each row. It is a record of research, not a recommendation, and it is open to free members.
Which symptoms are expected and which mean stop and get help: side effects and red flags.
Tap a claim to see what the studies found.
DREAMS-3 found 10.3% weight loss on mazdutide 6 mg versus 6.0% on semaglutide 1 mg in Chinese adults with diabetes and obesity, per a company announcement. That semaglutide dose is the diabetes dose, not the 2.4 mg obesity dose, and the full paper was not available to us.
It is approved only in China. In the US it is an unapproved drug, cannot be compounded, and online vials are unregulated research chemicals.
Weight loss climbed with dose up to 16 mg, but so did dropouts: 20% quit 16 mg for side effects in the US phase 2.
The glucagon mechanism makes this plausible and imaging studies show liver-fat drops, but no published head-to-head liver trial against a GLP-1-only drug has reported.
Not applicable to the approved product, which is supplied as a ready-made injection in China; storage follows the Chinese prescribing information.
No public data for research-market vials.
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