Mazdutide

What Is Mazdutide?

Mazdutide, also known by its development codes IBI362 and LY3305677, is a synthetic peptide modeled on oxyntomodulin, a natural hormone fragment that activates both the GLP-1 receptor and the glucagon receptor. It was originally developed within Eli Lilly's GLP-1/glucagon co-agonist research program and later licensed to Innovent Biologics, a Chinese biopharmaceutical company, for further development.

Mazdutide's regulatory path is notable: it became the first GLP-1/glucagon dual agonist to receive full approval for obesity anywhere in the world, cleared by China's National Medical Products Administration based on its Phase 3 GLORY-1 trial data. It's approved in China for both chronic weight management and glycemic control in type 2 diabetes, though it has not gone through FDA review in the United States.

What Mazdutide is Being Researched For?

• Body Weight in Obesity

  The Phase 3 GLORY-1 trial found that Mazdutide 9 mg produced weight loss exceeding 20% in obese adults without type 2 diabetes over roughly a year of treatment with a two-step dose titration, results that supported its NMPA approval.^[1]

• Glycemic Control in Type 2 Diabetes

  A head-to-head Phase 3 trial (DREAMS-3) in Chinese patients with type 2 diabetes and obesity found Mazdutide outperformed semaglutide on its primary endpoint, the combined measure of achieving target HbA1c alongside at least 10% body weight reduction.^[2]

• Dose-Finding and Safety Research

  Earlier Phase 1b and Phase 2 trials established Mazdutide's dose-response relationship and safety profile, finding weight reductions of up to nearly 10% at 12 weeks in dose-ranging studies that preceded the larger Phase 3 program.^[3]

How Mazdutide Works

• Activating Two Receptors at Once

  Research points to Mazdutide binding both the GLP-1 receptor and the glucagon receptor simultaneously, following the same theoretical rationale as retatrutide and survodutide: combining GLP-1's effects on insulin and appetite with glucagon's effects on energy expenditure and liver fat metabolism.^[1]

• Outperforming a Single-Receptor Comparator

  Research points to a direct head-to-head trial finding Mazdutide produced greater weight and blood sugar improvements than semaglutide, a GLP-1-only medication, in Chinese patients with type 2 diabetes and obesity, providing direct comparative evidence for the added glucagon receptor component.^[2]

• A Fatty-Acid-Modified Design for Extended Activity

  Research points to Mazdutide being built with a fatty acid side chain attached to its oxyntomodulin-based structure, extending its activity to support once-weekly dosing, similar to the design approach used in other long-acting peptides in this drug class.

Reconstitution and Handling

Mazdutide is approved and marketed in China, but research-grade vials sold as lyophilized powder are also common in other markets and require reconstitution with bacteriostatic water before use. Water should be added slowly rather than injected directly into the powder, and the vial should be swirled, not shaken.

Since the amount of water used affects the concentration of the final solution, researchers often use a dosage calculator to work this out before mixing. Keel Bio's calculator is a commonly used tool for this. Once reconstituted, the solution is kept refrigerated to help preserve its stability.

Key Takeaways

Mazdutide holds a notable place in metabolic peptide research as the first GLP-1/glucagon dual agonist to achieve full regulatory approval anywhere in the world, backed by completed Phase 3 trials in China showing weight loss exceeding 20% and superiority over semaglutide in a head-to-head comparison. Its approval remains geographically limited to China, and direct comparisons to tirzepatide or retatrutide in broader international populations have not yet been completed.

Frequently Asked Questions

Sources and Research

1. Ji L, et al. Mazdutide, a GLP-1 and glucagon receptor dual agonist, for weight management in obese Chinese adults: a randomized, double-blind, placebo-controlled, phase 3 trial. EClinicalMedicine. 2026.
2. DREAMS-3 investigators. Mazdutide versus semaglutide in Chinese adults with type 2 diabetes and obesity: a phase 3 randomized trial. 2025.
3. Ji L, et al. Safety and efficacy of a GLP-1 and glucagon receptor dual agonist mazdutide (IBI362) 9 mg and 10 mg in Chinese adults with overweight or obesity: a randomised, placebo-controlled, multiple-ascending-dose phase 1b trial. EClinicalMedicine. 2022;54:101691.