Where to Buy Mazdutide: Vendor Comparison, Benefits & Side Effects

Mazdutide is a synthetic peptide analogue of oxyntomodulin, a gut hormone, built to activate both the GLP-1 and glucagon receptors. Eli Lilly developed it as LY3305677 and licensed it to Innovent Biologics for China as IBI362. The vials listed here are sold strictly as a research chemical: not the approved pharmaceutical, not approved by the FDA or any regulator outside China, and nothing on this page is medical advice.

Unusually for this index, the evidence is clinical: phase 1 to 3 trials in Chinese adults with overweight, obesity or type 2 diabetes, and 2025 approvals in China for chronic weight management and for type 2 diabetes. That evidence belongs to the pharmaceutical-grade drug under medical supervision; research-grade material has no data of its own, and its identity rests on the vendor's certificate of analysis.

PeptidesFinder's role is narrower than the science. We track which research vendors list mazdutide, normalise every listing to a price per milligram so vial sizes can be compared, and record whether a recent certificate of analysis is on file. The comparison below is re-checked on a schedule; confirm current pricing on the vendor's own site before ordering.

Mazdutide's pharmacology is better characterised than that of almost anything else in this index, because it has been through a full clinical development programme. The mechanisms below come from three kinds of evidence — receptor assays, rodent studies of the dual-agonist class, and published human trials of the pharmaceutical product — and each claim says which.

Receptor targets. Mazdutide is a synthetic analogue of oxyntomodulin, a gut peptide that naturally activates both the glucagon-like peptide-1 (GLP-1) receptor and the glucagon receptor. In cell-based receptor assays the molecule activates both. It carries a C20 fatty-diacid side chain that binds serum albumin; in phase 1 pharmacokinetic studies in humans this gave a half-life measured in days rather than hours.

GLP-1 receptor component. This is the better-understood half. Across the GLP-1 receptor agonist class, rodent and human pharmacology show glucose-dependent stimulation of insulin secretion, suppression of post-meal glucagon release, slowed gastric emptying and reduced food intake acting through hypothalamic and brainstem appetite circuits. The reductions in body weight and glycated haemoglobin recorded as trial endpoints for mazdutide are consistent with this component.

Glucagon receptor component. This is what separates the molecule from a plain GLP-1 receptor agonist, and where the evidence is thinner. In diet-induced obese mice, oxyntomodulin-based GLP-1/glucagon co-agonists produced greater weight loss than GLP-1 agonism alone, attributed to increased energy expenditure and hepatic fatty-acid oxidation, with the GLP-1 component offsetting glucagon's tendency to raise blood glucose. Whether glucagon receptor agonism meaningfully raises energy expenditure in humans is unsettled for the class as a whole; for mazdutide specifically it remains a proposed mechanism, not a demonstrated one.

Hepatic and cardiometabolic endpoints. In the Chinese phase 2 and phase 3 trials, changes in liver fat content (measured by MRI in a subset of participants), serum lipids, blood pressure, serum uric acid and liver enzymes were reported as secondary or exploratory endpoints alongside body weight. These are observations in trial populations under medical supervision, not mechanistic proof, and they were made with the pharmaceutical product.

Clinical and regulatory context. Mazdutide was developed by Eli Lilly as LY3305677 and licensed to Innovent Biologics for development in China as IBI362. After the phase 3 GLORY-1 trial in adults with overweight or obesity, China's National Medical Products Administration approved it in June 2025 for chronic weight management, and in September 2025 approved a second indication, glycaemic control in adults with type 2 diabetes, on the DREAMS-1 and DREAMS-2 phase 3 trials. It is not approved by the FDA, the EMA or any regulator outside China. The most frequently reported adverse events in the trials were gastrointestinal.

None of this transfers to the vials sold by the vendors listed here. The clinical evidence belongs to the pharmaceutical-grade drug, manufactured under regulatory oversight and given under medical supervision; research-grade mazdutide sold as a research chemical is not that approved product, has no clinical data of its own, and is not approved for any medical use. Nothing above establishes its safety or efficacy in humans.