What is mazdutide?

A second drug built on the glucagon bet

Semaglutide and tirzepatide both lean on GLP-1. Tirzepatide adds GIP on top of it. Mazdutide takes a different second receptor entirely: glucagon. That puts it in the same family as survodutide, Boehringer Ingelheim and Zealand's dual agonist, and it shares the same basic logic as retatrutide, which adds glucagon on top of GLP-1 and GIP together. Glucagon receptors sit mostly in the liver, and activating them pushes the liver to burn fat directly, raising how much fuel the body burns at rest.

Mazdutide, internally coded IBI362, comes from Innovent Biologics, a Chinese biotech. Eli Lilly licensed the rights to develop and sell it everywhere outside Greater China, which is why an American reader is likely seeing this drug for the first time even though it has been on pharmacy shelves in China since 2025.

Already approved, just not here

China's National Medical Products Administration cleared mazdutide, sold there as Xinermei, for chronic weight management in June 2025. It picked up a second approval for type 2 diabetes in September 2025. That makes mazdutide the first dual GLP-1/glucagon agonist to reach approval anywhere in the world, ahead of survodutide and ahead of Lilly's own retatrutide.

None of that gets it into a US clinic. Eli Lilly is running its own global trial program, starting from Phase 2 in non-Chinese populations, to build the case for an FDA filing. No submission date has been announced. Industry estimates put a realistic FDA decision in the 2028 to 2029 range if the global trials go well, which puts mazdutide roughly where retatrutide and survodutide sit on the US timeline: real drugs with real data, years from a US prescription.

What the China trials found

The Phase 3 program run in Chinese adults is built around two names: GLORY, tested against placebo, and DREAMS, tested head-to-head against drugs already on the market.

GLORY-2, published in JAMA in June 2026, tested the 9mg dose against placebo in Chinese adults with obesity over 60 weeks. It found 16.65% mean weight loss against 1.50% on placebo, and 84.3% of the mazdutide group lost at least 5% of their body weight, compared with 33.1% on placebo.

GLORY-1, published earlier in the New England Journal of Medicine, tested the lower 6mg dose and found 12.55% weight loss at 32 weeks. Read together, the two trials show the expected dose-response curve: more drug, more weight loss, with the ceiling not yet obviously reached at 9mg.

Mazdutide vs semaglutide: the head-to-head trial

DREAMS-3 is the trial that matters most for how mazdutide gets judged against what American patients already use. It enrolled Chinese adults with both type 2 diabetes and obesity and ran mazdutide directly against semaglutide rather than placebo.

At 32 weeks, mazdutide produced 10.29% weight loss against 6% for semaglutide. On the combined measure the trial tracked, HbA1c under 7% plus at least 10% weight loss, 48% of mazdutide patients hit that bar against 21% on semaglutide. Two other DREAMS trials add more context: DREAMS-1 tested mazdutide against placebo and found 5.5% to 7.34% weight loss depending on dose at 24 weeks, and DREAMS-2 beat dulaglutide, an older GLP-1 drug, by a similar margin.

Beating semaglutide in its own trial is a real result. It is not the same as beating tirzepatide or retatrutide, and no trial has run that comparison yet.

Mazdutide vs tirzepatide and retatrutide

No head-to-head data exists between mazdutide and either of Eli Lilly's other two obesity drugs, so any comparison has to lean on separate trials rather than a shared study. On that basis, mazdutide is not the strongest option in the pipeline.

Trial duration and patient population differ enough across these three that the numbers should not be read as a precise ranking. What they do show is that mazdutide's published results so far land below tirzepatide, which is already FDA-approved and available today, and well below retatrutide's Phase 3 numbers. Mazdutide's real selling point is not raw efficacy. It is being first: the first dual GLP-1/glucagon drug anywhere to clear a national regulator.

Side effects and the glucagon question

The published trials report the same gastrointestinal side effects seen across the whole GLP-1 class: nausea, diarrhea, and related complaints, generally dose-dependent and strongest during dose escalation. The theoretical worry specific to this mechanism is that glucagon's core job in the body is to raise blood sugar, which sounds like a strange thing to add to a diabetes and obesity drug.

In practice, the trials have not shown a blood-sugar safety problem. Retatrutide and survodutide use the same glucagon-plus-GLP-1 pairing and report similar findings: the insulin release triggered by GLP-1 activation offsets glucagon's glucose-raising effect. That is the pharmacological bet behind all three drugs, and so far the human data backs it up. Longer-term safety data outside the trial window does not yet exist for any of them.

What to actually do with this if you are in the US

There is no legal path to mazdutide in the United States right now, and no compounded version should exist given it is not on any FDA bulk substances list. If you need treatment today, tirzepatide and semaglutide are the FDA-approved options with real-world track records; see semaglutide vs tirzepatide for how those two compare directly, or our comparison of GLP-1 programs for how to actually get access.

Worth tracking going forward: whether Lilly's global Phase 2/3 program in non-Chinese populations reproduces the China numbers, and how mazdutide eventually stacks up against survodutide, the other glucagon-pairing drug racing toward US approval on a similar timeline.