Mazdutide Benefits: What Studies Report

Mazdutide (studied under the identifiers IBI362 and LY3305677) is a once-weekly injectable dual agonist of the glucagon-like peptide-1 receptor (GLP-1R) and the glucagon receptor (GCGR), a design described in published work on the molecule (PMID 40479843). It is a prescription medicine, not a supplement. Regulatory status differs by jurisdiction: mazdutide has been approved in China for weight management in adults, and it has not been approved by the United States Food and Drug Administration. This page is for educational purposes only and is not medical advice; consult a licensed physician about any medicine, including mazdutide, and about whether any treatment is appropriate.

The sections below organise the published literature by outcome domain. Each entry states the study type, the population studied and the direction of effect the researchers reported. Nothing here is a claim that mazdutide will produce a given result for any individual.

Evidence map by outcome domain

Body weight in adults with obesity or overweight

The largest published trial in this domain was a 2025 randomised, placebo-controlled study of once-weekly mazdutide in Chinese adults with obesity or overweight, in which the researchers reported greater mean percentage reductions in body weight with mazdutide 4 mg and 6 mg than with placebo (PMID 40421736). In that study the reported least-squares mean percentage change in body weight was approximately −10% with 4 mg and approximately −12.6% with 6 mg, against essentially no change in the placebo group (PMID 40421736).

Earlier, a phase 2 randomised controlled trial published in 2023 evaluated mazdutide at 3 mg, 4.5 mg and 6 mg once weekly in Chinese overweight adults or adults with obesity and reported dose-related reductions in body weight compared with placebo (PMID 38092790). A separate phase 1 trial of higher doses in adults with overweight or obesity also reported reductions in body weight, and because it was a phase 1 study it was small and short by design (PMID 40832785).

Two framing points matter when reading these results. First, the participants in the published randomised trials cited here were Chinese adults, so the degree to which the reported magnitudes transfer to other populations was not tested in those studies (PMID 40421736). Second, trial weight change is a group average with wide individual variation around it; the published reports describe mean changes, not an outcome for any one person (PMID 38092790).

Blood glucose and type 2 diabetes

A randomised, double-blind, placebo-controlled phase 2 trial in Chinese patients with type 2 diabetes evaluated the efficacy and safety of mazdutide and reported reductions in glycated haemoglobin together with reductions in body weight relative to placebo (PMID 37943529). A later phase 3 placebo-controlled trial in Chinese adults with type 2 diabetes likewise reported greater reductions in HbA1c and in body weight with mazdutide than with placebo (PMID 41407859).

Head-to-head against an active comparator

Active-comparator trials are more informative than placebo trials for questions about relative performance. In a randomised trial comparing mazdutide with dulaglutide in Chinese adults with type 2 diabetes, the researchers reported greater reductions in HbA1c and in body weight with mazdutide than with dulaglutide (PMID 41407860). That comparison was against one specific GLP-1 receptor agonist at the doses studied, and does not generalise to every other agent in the class (PMID 41407860).

How mazdutide sits among other weight-management drugs

An updated systematic review and network meta-analysis of randomised controlled trials pooled evidence on seven GLP-1 receptor agonists and polyagonists for weight loss in patients with obesity or overweight and ranked the agents by percentage weight change (PMID 39305981). Network meta-analyses rely substantially on indirect comparison, so the rankings they report are weaker evidence than a direct head-to-head trial (PMID 39305981).

Narrative and systematic reviews of the development pipeline have placed mazdutide within the broader category of incretin-based and hormone-based obesity pharmacotherapy. A 2025 systematic review of emerging pharmacotherapies for obesity catalogued agents in development alongside approved drugs (PMID 39952695), a 2024 review article surveyed approved and emerging hormone-based anti-obesity medications (PMID 39676791), and a 2026 Endocrine Reviews article reviewed novel GLP-1-based medications for type 2 diabetes and obesity (PMID 41054801). Reviews summarise and interpret primary trials; they do not add new participants or new outcome data (PMID 39952695).

The glucagon-receptor component and energy expenditure

The pharmacological rationale for combining GLP-1 and glucagon receptor agonism — rather than GLP-1 agonism alone — is discussed in reviews of GLP-1-based and multi-receptor medicines, which describe the receptor targets and the proposed metabolic consequences of each component (PMID 41054801). Mazdutide itself is characterised in published work as a dual GLP-1R/GCGR agonist (PMID 40479843). A mechanistic rationale is not an outcome: the cited reviews describe why the design was pursued, not a demonstrated clinical advantage of glucagon agonism for any specific endpoint (PMID 39952695).

Brain and cognitive outcomes: preclinical only

A 2025 study in EBioMedicine examined mazdutide in the context of diabetes-associated cognitive dysfunction and used multi-omics analysis to explore mechanism, reporting mitigation of the cognitive phenotype in that experimental setting (PMID 40479843). This was preclinical, mechanistic research, not a clinical trial in people, and the researchers' findings do not establish a cognitive benefit in patients (PMID 40479843).

Outcomes people ask about where mazdutide evidence is thin or absent

• Cardiovascular event reduction. The cited mazdutide trials measured weight and glycaemic endpoints rather than major adverse cardiovascular events (PMID 40421736). A 2026 review in The Lancet Diabetes & Endocrinology discussed multisystem outcomes reported for obesity medications beyond weight loss as a class-level question (PMID 42208956); class-level discussion is not mazdutide-specific outcome evidence.
• Kidney, sleep apnoea and osteoarthritis endpoints. These have been examined for other agents and are discussed in the multisystem review (PMID 42208956); the mazdutide trials cited on this page did not report them as primary endpoints (PMID 41407859).
• Muscle mass, body composition and "toning". The randomised trials cited here reported body-weight change rather than detailed composition outcomes (PMID 38092790).
• Longevity, anti-ageing, mood or cosmetic claims. No study in this citation set tested such endpoints for mazdutide; reviews of the field do not report them either (PMID 41054801).
• Durability after stopping. The published trials cited here reported on-treatment periods; what happens after discontinuation was not their reported focus (PMID 40421736).

Adverse Events: What Studies Report

In the 2025 randomised placebo-controlled trial of once-weekly mazdutide in Chinese adults with obesity or overweight, the researchers reported that gastrointestinal events — including nausea, diarrhoea and vomiting — were among the most common adverse events and were predominantly mild to moderate in severity (PMID 40421736). Gastrointestinal adverse events were also the most frequently reported category in the phase 2 trial in Chinese overweight adults or adults with obesity (PMID 38092790) and in the phase 2 trial in Chinese patients with type 2 diabetes (PMID 37943529).

Reviews of incretin-based and hormone-based obesity pharmacotherapy similarly describe gastrointestinal tolerability as the dominant safety consideration reported across this drug class (PMID 39952695, PMID 39676791). Trial safety populations are selected by eligibility criteria and followed for finite periods, so trial adverse-event rates do not describe risk in people who would not have qualified for the study (PMID 41407859). Safety questions about an individual belong with a prescribing clinician.

How to read "benefits" language about mazdutide

1. Check the population. The randomised evidence cited here was generated in Chinese adults with obesity, overweight or type 2 diabetes (PMID 40421736).
2. Check the comparator. Placebo-controlled results and active-comparator results answer different questions, and only one cited trial compared mazdutide with another GLP-1 receptor agonist (PMID 41407860).
3. Check the species. The cognition work was preclinical and multi-omics based (PMID 40479843).
4. Check whether the endpoint was measured at all. Many claimed benefits were simply not endpoints in the cited trials (PMID 37943529).

Mazdutide is a prescription product wherever it is authorised, and decisions about eligibility, dose, monitoring and discontinuation are made by a licensed prescriber who can review an individual's history. This page summarises published findings for education and does not recommend, endorse or direct any use.

References

• Once-Weekly Mazdutide in Chinese Adults with Obesity or Overweight (The New England Journal of Medicine, 2025)
• A phase 2 randomised controlled trial of mazdutide in Chinese overweight adults or adults with obesity (Nature Communications, 2023)
• Mazdutide reduces body weight in adults with overweight or obesity: A high-dose Phase 1 trial (Diabetes, Obesity & Metabolism, 2025)
• Efficacy and Safety of Mazdutide in Chinese Patients With Type 2 Diabetes: A Randomized, Double-Blind, Placebo-Controlled Phase 2 Trial (Diabetes Care, 2024)
• Mazdutide versus placebo in Chinese adults with type 2 diabetes (Nature, 2026)
• Mazdutide versus dulaglutide in Chinese adults with type 2 diabetes (Nature, 2026)
• Seven glucagon-like peptide-1 receptor agonists and polyagonists for weight loss in patients with obesity or overweight: an updated systematic review and network meta-analysis of randomized controlled trials (Metabolism: Clinical and Experimental, 2024)
• Emerging pharmacotherapies for obesity: A systematic review (Pharmacological Reviews, 2025)
• Novel GLP-1-based Medications for Type 2 Diabetes and Obesity (Endocrine Reviews, 2026)
• Approved and Emerging Hormone-Based Anti-Obesity Medications: A Review Article (Indian Journal of Endocrinology and Metabolism, 2024)
• Beyond weight loss: multisystem benefits of obesity medications (The Lancet Diabetes & Endocrinology, 2026)
• Mazdutide, a dual agonist targeting GLP-1R and GCGR, mitigates diabetes-associated cognitive dysfunction: mechanistic insights from multi-omics analysis (EBioMedicine, 2025)