Mazdutide (IBI362): Clinical Overview for Providers

Mazdutide, developed under the codes IBI362 and LY3305677, is a dual glucagon and GLP-1 receptor agonist derived from oxyntomodulin. It has been developed principally by Innovent Biologics under a license originating with Eli Lilly, and the bulk of its clinical program has been conducted in China.

This guide situates Mazdutide within the broader field of peptide therapy and is written for clinicians. It is clinical education, not medical advice, and nothing here should be read as a treatment recommendation or protocol.

What is mazdutide?

Mazdutide is a synthetic peptide analog of oxyntomodulin, a hormone released from intestinal L-cells after eating. Oxyntomodulin is biologically interesting because nature already built it as a dual agonist: it activates both the GLP-1 receptor and the glucagon receptor, though weakly at each and with a half-life far too short to be useful as a drug.

Mazdutide is that natural template engineered into a viable therapeutic — retaining dual receptor activity while adding the stability needed for weekly subcutaneous dosing. This is a different design philosophy from survodutide, which arrives at similar dual activity through a different scaffold.

How mazdutide works

The GLP-1 arm supplies the familiar effects: glucose-dependent insulin secretion, glucagon suppression, delayed gastric emptying, and appetite reduction. The glucagon arm contributes increased energy expenditure and hepatic fat oxidation.

Balancing the two is the central engineering problem. Too much glucagon activity risks working against glycemic control; too little forfeits the metabolic-rate benefit that justified adding it. The ratio of receptor potencies is therefore a deliberate design choice that differs between dual agonists, and it is a large part of why two drugs described identically as glucagon/GLP-1 agonists can behave differently in patients.

What the evidence shows

Clinical trials have reported dose-dependent reductions in body weight and HbA1c, with the weight results in obesity trials placing it broadly in the range achieved by other modern incretin-based agents. Studies have also examined effects on hepatic fat.

Two interpretive cautions apply. Much of the trial work was conducted in Chinese populations, and body weight, baseline BMI distribution and metabolic phenotype differ meaningfully from a typical North American obesity trial population — results do not transfer automatically. And as with every agent in this class, the gastrointestinal adverse effect profile is dose-related and shapes the achievable dose.

Regulatory activity for mazdutide has been centered in China rather than the United States. Its approval status in any given jurisdiction should be verified directly rather than inferred, as this is exactly the kind of detail that changes.

Status and what to tell patients

Mazdutide is not FDA-approved and is not available for prescribing in the United States. Its presence in international coverage of the obesity drug pipeline means patients encounter the name and sometimes attempt to source it, which is a genuine safety concern: material sold under an investigational drug name outside a trial has no verified identity, purity, or dose.

The useful clinical position is that the mechanism is legitimate and the development program is real, while access in the US is not. Patients wanting an approved option should be directed to agents that have completed the US regulatory path. Our peptide formulary tracks status across every agent in this category.