Biohacking Kompakt

Peptide & Experimental

Mazdutide

GLP-1 / glucagon dual agonist · IBI362, LY3305677

Mazdutide is a weight-loss drug that mimics two hormone signals at once: GLP-1, the principle behind semaglutide, and glucagon. Unlike many candidates in this class, it is no longer purely an investigational drug. It has been approved in China since June 2025, but not in Europe.

In brief

Mazdutide activates the GLP-1 and glucagon receptors and is injected once a week. In the large phase 3 trial GLORY-1 with 610 participants, people lost an average of 11.00 to 14.01 percent of their weight after 48 weeks, while on placebo they gained slightly. In GLORY-2, it was 16.65 percent after 60 weeks with the higher dose. The evidence is strong but comes almost entirely from China, and gastrointestinal complaints are very common. Mazdutide is not approved in Germany; what is offered online here is untested goods.

What mazdutide is

Mazdutide, development name LY3305677 or IBI362, comes from the Eli Lilly lab and is developed and marketed in China by Innovent Biologics. It is a peptide derived from oxyntomodulin. This gut hormone naturally activates both receptors, the one for GLP-1 and the one for glucagon.

In June 2025, mazdutide received its first approval worldwide in China, under the name Xinermei, for long-term weight management in adults with a BMI of 28 or more, or 24 or more with a weight-related comorbidity. In September 2025, approval for blood sugar control in type 2 diabetes followed in China.

How it is supposed to work

The GLP-1 part works as with semaglutide: less appetite, a better insulin response after meals, slower gastric emptying. This is well measured in humans and explains a large part of the weight loss.

The glucagon part is the real difference. Glucagon is the counter-hormone to insulin. It mobilizes energy from the liver and promotes fat breakdown there. The hope: more energy expenditure and less liver fat than with GLP-1 alone. Whether energy expenditure actually rises on mazdutide has not been measured in humans, however. The specialist literature cautiously phrases this as a possible increase. What can be measured, by contrast, are the metabolic consequences: in a meta-analysis, mazdutide improved waist circumference, blood lipids, liver enzymes and uric acid.

Where it stands

Mazdutide is the rare case in which several large approval trials actually exist for a drug from the biohacking scene. Four phase 3 trials have been published, two on weight loss and two on type 2 diabetes, plus a phase 2 trial from the US. Further trials are under way, including on the fatty liver inflammation MASH, on sleep apnea, on heart failure, and a direct comparison with semaglutide in overweight with fatty liver.

Outside China, mazdutide is not approved anywhere. In the US, Lilly has so far tested it only in phase 1 and phase 2 trials.

What is well supported

Weight loss has been shown in several large, double-blind trials. In GLORY-1, both primary endpoints were met after 32 weeks: minus 10.09 and minus 12.55 percent versus plus 0.45 percent on placebo, and 82.0 percent of participants on the higher dose lost at least 5 percent. After 48 weeks, 49.5 percent on the higher dose achieved at least 15 percent, versus 2.0 percent on placebo. GLORY-2 confirmed this in more severe obesity with minus 16.65 percent after 60 weeks. That the effect is not tied to the Chinese population is shown by a US trial by Lilly with 179 participants: there, up to minus 18.1 percent after 32 weeks versus minus 0.9 percent on placebo.

In type 2 diabetes, mazdutide lowered the long-term blood sugar marker HbA1c by 1.57 to 2.15 percentage points in DREAMS-1, versus 0.14 on placebo. In DREAMS-2, it did better on HbA1c and weight than the established GLP-1 drug dulaglutide. A meta-analysis of 9 randomized trials with 2,292 participants summarizes this: dose-dependent weight loss and better blood sugar values, plus more favorable blood lipids, liver enzymes and uric acid.

What the studies show

GLORY-1 (NEJM 2025)

Phase 3, double-blind, 610 Chinese adults with overweight or obesity, two doses against placebo over 48 weeks. Average baseline weight 87.2 kilos. Primary endpoint met after 32 weeks; after 48 weeks, minus 11.00 and minus 14.01 percent versus plus 0.30 percent. Discontinuations because of side effects were 1.5 and 0.5 percent, versus 1.0 percent on placebo.

GLORY-2 (JAMA 2026)

Phase 3 at 27 clinics, 461 people treated with a BMI of 30 or more, on average 33.9 years old, higher dose against placebo over 60 weeks. Result: minus 16.65 percent versus minus 1.50 percent, at least 5 percent loss in 84.3 versus 33.1 percent. Vomiting occurred in 53.1 percent, nausea in 46.9 percent.

DREAMS-1 and DREAMS-2 (Nature 2026)

Two phase 3 trials in type 2 diabetes. DREAMS-1 with 320 participants against placebo over 24 weeks: HbA1c minus 1.57 and minus 2.15 percentage points, weight minus 5.61 and minus 7.81 percent. DREAMS-2 with 731 participants against dulaglutide over 28 weeks: non-inferior and superior on HbA1c, and 3.78 and 5.76 percentage points more weight loss.

US phase 2 (Lancet Diabetes Endocrinol 2026)

Double-blind at 24 centers in the US, 179 adults without diabetes, three dose groups over 48 weeks, funded by Eli Lilly. After 32 weeks, minus 7.3, minus 15.6 and minus 18.1 percent versus minus 0.9 percent. At the highest dose, 20 percent stopped because of side effects, mainly because of gastrointestinal complaints.

Where the data stop

The data base is large but one-sided. All phase 3 trials were conducted in China. Outside China, there is one phase 2 trial with 179 participants. The authors of the meta-analysis explicitly call for longer trials with people of different backgrounds to clarify durability, generalizability and cardiovascular safety. The longest published treatment duration is 60 weeks. There are no data on heart attack, stroke or mortality.

Two popular promises are not supported. That the glucagon part increases energy expenditure has not been measured in humans for mazdutide. And the liver benefit so far rests on better liver enzymes. Trials with liver biopsy or direct measurement of liver fat are still under way. The published direct comparison with semaglutide is also missing. The DREAMS-3 trial with 349 participants was due to end in early 2026; results have not been published to date. Whether mazdutide is better than the drugs approved in Europe therefore cannot be said.

Status, approval and legal

Mazdutide has been approved in China for weight management since June 2025 and for type 2 diabetes since September 2025. In Germany and the EU, it is not an approved medicine and is not available through regular channels. Offers online are neither tested nor legally marketable as medicines. We therefore give no dosage information. Mazdutide is not named on the World Anti-Doping Agency's 2026 Prohibited List. The catch-all class S0 covers only substances not approved by any governmental health authority, and mazdutide has an approval in China. Anyone who competes in tested sport should nonetheless clarify this with their anti-doping organization beforehand.

Safety

The typical side effect picture is that of the GLP-1 class, if anything more pronounced: in GLORY-2, 53.1 percent had vomiting, 46.9 percent nausea and 39.4 percent diarrhea, mostly mild to moderate. 2.9 percent stopped because of side effects there, whereas at the highest dose of the US trial it was 20 percent. Overall, serious side effects and discontinuations in the meta-analysis were comparable with the control groups. Like other glucagon/GLP-1 dual agonists, mazdutide raises heart rate, according to one review to a similar extent as pure GLP-1 drugs. Cardiovascular safety still has to be clarified substance by substance. Mazdutide is not suitable during pregnancy and breastfeeding or for children and adolescents outside trials. The biggest practical risk in Germany is gray-market goods whose contents nobody controls.

BK-Score Well supported, heavily overhyped

Human evidence8
Mechanism8
Safety data6
Hype gap4
Track record of use4

Four published phase 3 trials met their primary endpoints: GLORY-1 (NEJM 2025) randomized 610 Chinese adults over 48 weeks, with 11.00 to 14.01 percent weight reduction versus plus 0.30 percent on placebo; GLORY-2 (JAMA 2026) showed 16.65 percent after 60 weeks with a higher dose, versus minus 1.50 percent. In type 2 diabetes, mazdutide lowered HbA1c versus placebo (DREAMS-1, 320) and more than dulaglutide (DREAMS-2, 731). In China, the substance is approved for obesity and type 2 diabetes. Dual GLP-1 and glucagon receptor agonism has been confirmed in humans; higher energy expenditure has not been measured. The phase 3 trials were conducted exclusively in China, and outside China there is one US phase 2 trial with 179 participants; in Germany there is no approval – a point sales pages regularly leave out.

The score rates the state of knowledge, not the substance. “Safety data 9” means well studied – not harmless.
Subjective assessment by Biohacking Kompakt based on published scoring rules – not a scientific rating and not a medical recommendation. Rules and all ratings (German)

Frequently asked questions about Mazdutide

Is mazdutide approved in Germany?

No. Mazdutide has so far been approved only in China, for weight management since June 2025 and for type 2 diabetes since September 2025. In the EU, there is no approval and no regular way to obtain it.

How much weight do people lose with mazdutide?

In the phase 3 trial GLORY-1, it was an average of 11.00 to 14.01 percent of body weight after 48 weeks, depending on the dose. In GLORY-2, with the higher dose, 16.65 percent after 60 weeks. On placebo, weight stayed almost the same.

Is mazdutide better than semaglutide or tirzepatide?

That is open. There is no published direct comparison yet. Against the older GLP-1 drug dulaglutide, mazdutide was superior on blood sugar and weight; a comparison with semaglutide is under way.

What does the glucagon part do?

Glucagon is meant to mobilize energy from the liver and promote fat breakdown there. In the trials, blood lipids, liver enzymes and uric acid improved. However, higher energy expenditure has not been measured in humans for mazdutide.

What are the side effects of mazdutide?

Mainly nausea, vomiting and diarrhea. In GLORY-2, 53.1 percent had vomiting and 46.9 percent nausea, mostly mild to moderate. In addition, there is a class-typical increase in heart rate. Long-term data beyond 60 weeks are lacking.

Is mazdutide banned in sport?

It is not named on the 2026 Prohibited List. By its wording, the catch-all class for substances not approved anywhere does not apply, because mazdutide is approved in China. Anyone who is tested should ask their anti-doping organization before any use.

Related

Sources

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Information only, not medical advice and no usage or dosing recommendation. Prescription-only and unapproved substances belong in medical hands. Last updated: 2026-09-30.