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Mazdutide

What it is. What the evidence says.

A lab-made peptide medicine that switches on two hormone signals, GLP-1 and glucagon, which affect appetite, blood sugar and energy use. It was first made by Eli Lilly.

Moderate EvidenceInvestigational

Predominant research setting. Clinical confidence is claim-specific.

Updated Scientific review pending
Start with the basics Regulatory status ↓
Sequence diagram and chemical structure information for Mazdutide.
Mazdutide Chemical Structure & Sequence · Inside Peptides Scientific Library
Compound
Mazdutide
Human effectiveness
Phase 3 trials in Chinese adults show weight and glucose benefits, and a U.S. phase 2 trial showed weight loss; not FDA-approved
Regulatory status
Investigational Drug
START HERE · PLAIN LANGUAGE

Mazdutide: the basics

What is it?

A lab-made peptide medicine that switches on two hormone signals, GLP-1 and glucagon, which affect appetite, blood sugar and energy use. It was first made by Eli Lilly.

Research paper 1 ↗Research paper 2 ↗Research paper 3 ↗

What do people claim it helps with?

Weight loss and better blood-sugar control in type 2 diabetes.

What has research actually shown?

Large controlled trials in Chinese adults found more weight loss than placebo and better blood sugar than placebo or another diabetes drug. A smaller U.S. trial also found weight loss.

Research paper 1 ↗Research paper 2 ↗Research paper 3 ↗

Has this been demonstrated in people?

Phase 3 randomized trials mostly in China, and a phase 2 trial in the U.S., all funded by the companies developing it.

Research paper 1 ↗Research paper 2 ↗Research paper 3 ↗

What side effects, risks and unknowns should I understand?

Nausea, vomiting, diarrhoea and reduced appetite were common in trials. In the highest dose group of the U.S. trial, one in five people stopped because of side effects.

FDA safety information 1 ↗Research paper 2 ↗

Is it an approved medicine?

No FDA-approved medicine contains mazdutide. It is approved in China, but that does not make it approved or legal to sell as a medicine in the U.S.

FDA safety information ↗

Approval here means U.S. FDA approval and applies to a particular product, formulation and use. This is a starting overview, not a complete side-effect list. Sources checked 10 October 2026; independent scientific review pending.

How is it used or studied?

A once-weekly injection in trials and in China. There is no U.S.-approved product; online "research" versions are illegal unapproved drugs.

Different routes and formulations can have different effects. A study of one product does not validate every product with the same peptide name.

A common misunderstanding

Mazdutide is not survodutide, pemvidutide or semaglutide. Approval in one country does not carry over to another.

What should I ask a clinician?
  • What diagnosis or goal are we trying to address, and what established options are available?
  • Was the expected benefit shown in people like me, using this exact product?
  • How could my medicines, health conditions or pregnancy plans affect the risks?
  • What monitoring is needed, and what would tell us the treatment is helping or should be stopped?
What do the research words mean?
Peptide
A short chain of amino acids, the building blocks of proteins.
Preclinical
Research in cells, tissues or animals before dependable treatment evidence in people.
Controlled trial
A study comparing a treatment with another treatment or a placebo to help separate its effects from other explanations.
Biomarker
A measurement, such as a hormone level. A change does not necessarily mean someone feels better or lives longer.
THE AVAILABLE RESEARCH

Mazdutide Evidence & Clinical Profile

Human Clinical Evidence

Human Study Limits

Mazdutide has been investigated in clinical contexts. Patient outcomes must be evaluated against study size, design, and control cohorts.

Preclinical & Pharmacological Data

Laboratory & In Vivo Assays

Cellular and animal disease models examine receptor binding affinities and signaling cascades, which require human confirmation.

Understand our evidence labels →

IDENTITY & STRUCTURE

What is Mazdutide?

Mazdutide (IBI362 / LY3305677) is Mazdutide is a once-weekly injectable peptide that activates both GLP-1 and glucagon receptors. Originated by Eli Lilly and developed in China by Innovent Biologics, it was approved in China in 2025 for weight management and type 2 diabetes. It is not FDA-approved; Lilly is studying it in U.S. trials. Aliases include: IBI362, IBI-362, LY3305677, LY-3305677.

Chemical sequence and molecular parameters of Mazdutide
Primary sequence schematic · Inside Peptides Molecular Database
Chemical reference
Sequence (one-letter)
N/A
Molecular formula
C207H317N45O65
Molecular weight
4476 g/mol (PubChem computed)
CAS Number
2259884-03-0
UNII Code
MB76Z4IBZ5
PubChem CID
167312357

Identifiers checked against PubChem and FDA's Global Substance Registration System on 13 October 2026. FDA substance record ↗ · PubChem record ↗ See all names and codes in the peptide name index.

HUMAN RESEARCH

Clinical Trials & Human Cohorts

Human research can examine tolerability, symptoms or patient outcomes. The design and comparator determine what each result can establish.

Phase 3 double-blind, placebo-controlled randomized trial; 48 weeks2025

Once-Weekly Mazdutide in Chinese Adults with Obesity or Overweight [1]

n = 610Chinese adults with BMI 28 or higher, or 24 to under 28 with a weight-related condition

What was reported

At 48 weeks mean weight change was −11.0% and −14.0% in the two mazdutide groups versus +0.3% with placebo.

What limits the conclusion

Chinese adults only, with Chinese BMI cut-offs; funded by Innovent. Gastrointestinal events were the most common side effects.

Read primary source ↗ (external website)
Phase 3 randomized, placebo-controlled trial; 24 weeks plus 24-week extension2026

Mazdutide versus placebo in Chinese adults with type 2 diabetes [2]

n = 320Chinese adults with type 2 diabetes managed by diet and exercise alone

What was reported

At 24 weeks HbA1c fell 1.57 and 2.15 percentage points with mazdutide versus 0.14 with placebo; weight fell 5.6% and 7.8% versus 1.3%.

What limits the conclusion

Short placebo-controlled period. Diarrhoea, decreased appetite and nausea were most common. Several authors are Innovent employees.

Read primary source ↗ (external website)
Phase 3 randomized, active-controlled trial; 28 weeks2026

Mazdutide versus dulaglutide in Chinese adults with type 2 diabetes [3]

n = 731Chinese adults with type 2 diabetes on oral glucose-lowering drugs

What was reported

Both mazdutide groups lowered HbA1c more than dulaglutide (differences −0.24 and −0.30 points) and reduced weight more (differences −3.8% and −5.8%).

What limits the conclusion

Short 28-week comparison against one GLP-1 drug. Gastrointestinal adverse events were more common than with dulaglutide.

Read primary source ↗ (external website)
Phase 2 double-blind, placebo-controlled randomized trial; 48 weeks2026

Efficacy and safety of mazdutide in adults with obesity or overweight: a US-based phase 2 trial [4]

n = 179U.S. adults without type 2 diabetes, 24 centres

What was reported

At 32 weeks mean weight change ranged from −7.3% to −18.1% across mazdutide groups versus −0.9% with placebo.

What limits the conclusion

Small trial funded by Eli Lilly. In the highest dose group, 20% stopped treatment because of adverse events, mainly gastrointestinal.

Read primary source ↗ (external website)
MECHANISMS OF ACTION

How the compound may work

Mechanisms describe how Mazdutide may affect biological processes. Laboratory findings and patient outcomes answer different questions.

01
Drug design, as described in trial reports

GLP-1 plus glucagon receptor activation

Mazdutide is a dual agonist: one molecule activates both the GLP-1 receptor and the glucagon receptor. Human trials measure the combined effect on weight and glucose; they do not show how much each receptor contributes. [1]

RESEARCH AREAS

Areas Being Studied

These research topics reflect active areas of scientific exploration, distinct from unverified commercial marketing claims.

Phase 3 (China) and phase 2 (U.S.) trials

Obesity

Weight loss in Chinese and U.S. adults with obesity or overweight. [1]

Phase 3 randomized trials in China

Type 2 diabetes

Glucose control and weight versus placebo and versus dulaglutide. [3]

Phase 2 randomized trial

U.S. development

Eli Lilly is testing mazdutide outside China, including at higher dose levels than those approved there; U.S. results so far are from phase 2. [4]

AT A GLANCE

Compare the study designs.

Overview of Key Mazdutide Studies: clinical and preclinical records
Study Design / sample Outcome type Key limitation
GLORY-1: obesity in China · 2025 [1] Phase 3 double-blind, placebo-controlled randomized trial; 48 weeks
n = 610		 Clinical endpoint evaluation Chinese adults only, with Chinese BMI cut-offs; funded by Innovent. Gastrointestinal events were the most common side effects.
Type 2 diabetes vs placebo · 2026 [2] Phase 3 randomized, placebo-controlled trial; 24 weeks plus 24-week extension
n = 320		 Clinical endpoint evaluation Short placebo-controlled period. Diarrhoea, decreased appetite and nausea were most common. Several authors are Innovent employees.
Type 2 diabetes vs dulaglutide · 2026 [3] Phase 3 randomized, active-controlled trial; 28 weeks
n = 731		 Clinical endpoint evaluation Short 28-week comparison against one GLP-1 drug. Gastrointestinal adverse events were more common than with dulaglutide.
U.S. phase 2: obesity · 2026 [4] Phase 2 double-blind, placebo-controlled randomized trial; 48 weeks
n = 179		 Clinical endpoint evaluation Small trial funded by Eli Lilly. In the highest dose group, 20% stopped treatment because of adverse events, mainly gastrointestinal.
FDA & SAFETY

Regulatory Status & Clinical Safety

Regulatory Classification

United States, checked 11 October 2026: not FDA-approved; no record appears in Drugs@FDA or DailyMed. FDA reports it has warned companies illegally selling unapproved mazdutide falsely labelled "for research purposes". China: Innovent announced NMPA approval for chronic weight management in adults (June 2025) and for glycaemic control in adults with type 2 diabetes (September 2025). A Chinese approval does not make it legal or approved in the U.S.

Safety Realities & Impurities

Safety depends on the molecule, formulation, route and evidence. A laboratory purity measurement alone cannot establish safety for human use.

REGISTRY CHECK

Clinical Trials Registry Records

Official registry records from ClinicalTrials.gov. Study registration does not imply government endorsement or guaranteed efficacy.

Phase 3Completed

A Study of IBI362 in Participants With Obesity or Overweight (GLORY-1) [5]

Planned enrollment
610 (actual enrollment)
Posted results
Pending in registry
Sponsor
Innovent Biologics (Suzhou) Co. Ltd.
Last updated
2024-11-12
NCT05607680 · Open registry ↗ (external website)
Phase 3Completed

A Study of IBI362 in Poorly Controlled Type 2 Diabetes Patients Only Through Diet and Exercise [6]

Planned enrollment
319 (actual enrollment)
Posted results
Pending in registry
Sponsor
Innovent Biologics (Suzhou) Co. Ltd.
Last updated
2024-08-20
NCT05628311 · Open registry ↗ (external website)
Phase 3Completed

A Study of IBI362 in Participants With Type 2 Diabetes [7]

Planned enrollment
731 (actual enrollment)
Posted results
Pending in registry
Sponsor
Innovent Biologics (Suzhou) Co. Ltd.
Last updated
2024-08-23
NCT05606913 · Open registry ↗ (external website)
Phase 2Completed

A Study of LY3305677 Compared With Placebo in Adult Participants With Obesity or Overweight [8]

Planned enrollment
179 (actual enrollment)
Posted results
Available
Sponsor
Eli Lilly and Company
Last updated
2026-04-21
NCT06124807 · Open registry ↗ (external website)
COMPETITIVE SPORT

WADA & Anti-Doping Regulations

Not Prohibited

WADA Anti-Doping Status

Mazdutide is not prohibited under current World Anti-Doping Agency (WADA) regulations. However, athletes must ensure unregulated preparations or unverified vendor products do not violate Section S0 (Non-approved substances). Last verified: October 2026.

SELECTED MILESTONES

Research Timeline

  1. 2025

    GLORY-1 published

    Phase 3 trial in Chinese adults reports 48-week weight results. [1]

  2. 2025

    Approved in China for weight management

    Innovent announces NMPA approval for chronic weight management in adults. [9]

  3. 2025

    Approved in China for type 2 diabetes

    Innovent announces NMPA approval for glycaemic control in adults with type 2 diabetes. [10]

  4. 2026

    Diabetes trials and U.S. phase 2 published

    Two phase 3 diabetes trials and a U.S. obesity trial report results. [4]

  5. 2026

    U.S. status

    Not FDA-approved. FDA has warned sellers of mazdutide falsely labelled as a research product. [11]

OPEN QUESTIONS

What Researchers Still Don't Know

Long-term safety profiles

Multi-year observational data in broader heterogeneous cohorts remains uncharacterized.

Optimal dose-response thresholds

Comparative trials optimizing minimal effective exposure versus adverse event rates.

Formulation bioavailability

Differences between oral, subcutaneous, and modified peptide delivery vehicles.

TRACEABLE SOURCES

References

Primary sources verified against PubMed / NLM and regulatory databases.

  1. Phase 3 RCT

    Once-Weekly Mazdutide in Chinese Adults with Obesity or Overweight ↗ (external website)

    Ji L et al. · N Engl J Med · 2025 DOI: 10.1056/NEJMoa2411528 ↗ (external website)
  2. Phase 3 RCT

    Mazdutide versus placebo in Chinese adults with type 2 diabetes ↗ (external website)

    Zhu D et al. · Nature · 2026 DOI: 10.1038/s41586-025-10026-w ↗ (external website)
  3. Phase 3 RCT

    Mazdutide versus dulaglutide in Chinese adults with type 2 diabetes ↗ (external website)

    Guo L et al. · Nature · 2026 DOI: 10.1038/s41586-025-10031-z ↗ (external website)
  4. Phase 2 RCT

    Efficacy and safety of mazdutide in adults with obesity or overweight: a US-based, multicentre, phase 2, randomised, placebo-controlled clinical trial ↗ (external website)

    Hsia SH et al. · Lancet Diabetes Endocrinol · 2026 DOI: 10.1016/S2213-8587(26)00160-9 ↗ (external website)
  5. Registry Record

    A Study of IBI362 in Participants With Obesity or Overweight (GLORY-1) ↗ (external website)

    ClinicalTrials.gov · 2024
  6. Registry Record

    A Study of IBI362 in Poorly Controlled Type 2 Diabetes Patients Only Through Diet and Exercise ↗ (external website)

    ClinicalTrials.gov · 2024
  7. Registry Record

    A Study of IBI362 in Participants With Type 2 Diabetes ↗ (external website)

    ClinicalTrials.gov · 2024
  8. Registry Record

    A Study of LY3305677 Compared With Placebo in Adult Participants With Obesity or Overweight ↗ (external website)

    ClinicalTrials.gov · 2026
  9. Company press release

    Innovent Announces Mazdutide, First Dual GCG/GLP-1 Receptor Agonist, Received Approval from China's NMPA for Chronic Weight Management ↗ (external website)

    Innovent Biologics · 2025
  10. Company press release

    Innovent Announces Mazdutide Received Approval from China's NMPA for Glycemic Control in Adults with Type 2 Diabetes ↗ (external website)

    Innovent Biologics · 2025
  11. FDA Safety Communication

    FDA's concerns with unapproved GLP-1 drugs used for weight loss ↗ (external website)

    U.S. FDA · 2026