Mazdutide

Mechanism

A dual GLP-1/glucagon receptor agonist being developed primarily for the Chinese market by Innovent Biologics (partnered with Eli Lilly). Activates two appetite and metabolism pathways simultaneously: GLP-1 (reduces appetite, slows stomach emptying) and glucagon (boosts fat burning and energy expenditure). Phase 3 data in China showed up to 14.4% body weight loss at 24 weeks.

Effects

Mazdutide (IBI362) is a dual GLP-1/glucagon receptor agonist developed by Innovent Biologics, designed to harness both incretin-mediated appetite suppression and glucagon-driven metabolic activation. The GLP-1 component works through established mechanisms: glucose-dependent insulin secretion, glucagon suppression post-meal, delayed gastric emptying, and central appetite reduction. What distinguishes mazdutide is the intentional inclusion of glucagon receptor agonism, which drives hepatic fat oxidation, increases energy expenditure via thermogenesis, and promotes amino acid catabolism. The glucagon component creates a metabolic profile distinct from pure GLP-1 agonists. By stimulating hepatic lipid oxidation, mazdutide may deliver enhanced reductions in liver fat content, making it particularly relevant for metabolic dysfunction-associated steatotic liver disease (MASLD). Increased energy expenditure from glucagon agonism could translate to greater total weight loss than GLP-1 alone, as the body burns more calories at rest rather than relying solely on caloric restriction from appetite suppression. However, glucagon also raises hepatic glucose output, which the GLP-1 component must counterbalance to maintain glycemic control. Chinese Phase 3 data have shown impressive weight loss results in the range of 10-15% body weight at higher doses, with favorable metabolic profiles including improvements in lipid panels, liver enzymes, and insulin sensitivity. The dual agonist approach means the cardiovascular and metabolic effects extend beyond what either receptor activation achieves alone, though long-term cardiovascular outcomes data are still pending.

Practitioner Guide

Mazdutide is currently progressing through regulatory pathways primarily in China, with global expansion plans under development. For practitioners tracking the pipeline, the key clinical differentiator versus pure GLP-1 agonists is the glucagon-mediated enhancement of energy expenditure and hepatic fat clearance. This makes mazdutide a compelling option for patients with significant hepatic steatosis alongside obesity, where the liver-directed effects of glucagon agonism add clinical value beyond weight loss alone. The direct competitor in the dual GLP-1/glucagon space is survodutide (Boehringer Ingelheim), which targets the same two receptors. Early cross-trial comparisons suggest broadly similar weight loss magnitudes, though head-to-head data do not exist. Survodutide has been more aggressively studied in MASH (metabolic dysfunction-associated steatohepatitis), while mazdutide Phase 3 programs have focused on obesity and type 2 diabetes in Chinese populations. The global relevance of mazdutide will depend on whether Innovent secures partnerships or regulatory approvals outside China. From a practical standpoint, GI tolerability with mazdutide appears comparable to other GLP-1 class agents, with nausea, vomiting, and diarrhea as the most common adverse events. The glucagon component does not appear to worsen glycemic control at therapeutic doses, confirming that the GLP-1 arm adequately offsets glucagon-driven hepatic glucose output. Practitioners should watch for Phase 3 readouts on liver fat endpoints and cardiovascular outcomes, as these will determine whether mazdutide carves out a distinct clinical niche or remains a regional alternative.

Evidence

• Once-Weekly Mazdutide in Chinese Adults with Obesity or Overweight

  Linong Ji et al. (2025) — N Engl J Med — PMID: 40421736

  In 610 Chinese adults with overweight or obesity, once-weekly mazdutide 4 mg and 6 mg produced mean body-weight reductions of 10.09% and 12.55% at week 32 versus 0.45% with placebo; at week 48 reductions were 11.00% and 14.01% with favorable cardiometabolic effects and mostly mild-to-moderate GI adverse events.

  strong

Research Summary

Tier 1 (robust evidence): Chinese Phase 3 trials (GLORY studies) in obesity and type 2 diabetes have demonstrated clinically significant weight loss (approximately 10-15% at higher doses) and A1c reductions competitive with leading GLP-1 agonists. Safety data from these trials show a GI adverse event profile consistent with the incretin class, with no unexpected safety signals from the glucagon component. Tier 2 (solid clinical data): Phase 2 dose-ranging studies established the therapeutic window where GLP-1 and glucagon agonism are balanced, confirming that glycemic control is maintained despite glucagon-driven hepatic glucose output. Biomarker data show reductions in liver enzymes (ALT, AST) and imaging-based liver fat content, supporting the mechanistic rationale for hepatic benefits. Comparison to survodutide relies on cross-trial analysis only; no head-to-head studies exist. Tier 3 (emerging/mechanistic): Preclinical and early clinical work suggests the glucagon component increases resting energy expenditure by 5-10%, contributing to weight loss beyond appetite suppression alone. Investigations into MASH-specific endpoints (fibrosis improvement, steatohepatitis resolution) are underway but have not yet reported pivotal results. Global regulatory strategy and potential partnerships outside China remain uncertain, which will determine whether mazdutide becomes available in Western markets.