Is mazdutide an approved drug, or is it research-use-only?

Mazdutide injection was approved for chronic weight management in China in 2025, but it is not approved by Health Canada, the FDA, or the EMA. Peptigo supplies mazdutide in Canada strictly for research use only (RUO). It is not for human or veterinary use, diagnosis, or treatment.

What is mazdutide and how does it work?

Mazdutide (IBI362 / LY3305677) is a once-weekly synthetic analog of the gut hormone oxyntomodulin. Researchers describe it as a dual agonist that activates both the GLP-1 receptor and the glucagon receptor, a combination studied for its effects on body weight and metabolic parameters.

What did clinical studies report about mazdutide?

In randomized placebo-controlled trials, investigators reported dose-dependent reductions in body weight (for example up to roughly 15% at 48 weeks with the 6 mg dose in the phase 3 GLORY-1 study), along with reported reductions in waist circumference, liver fat, blood pressure and lipids. These are study observations, not claims of benefit.

What is the chemical identity of mazdutide?

Mazdutide has CAS number 2259884-03-0. PubChem (CID 167312357) lists its molecular formula as C207H317N45O65 with a molar mass of about 4476 g/mol and InChIKey XRBYWQZGSZWYEJ-HMQIFOERSA-N. Some registry and vendor sources list the same CAS with a slightly different formula, C210H322N46O67 (~4563.1 g/mol). It is a lipidated peptide, not a simple linear peptide.

What adverse effects were reported in studies?

Across published trials, the most commonly reported treatment-emergent adverse events were mild-to-moderate gastrointestinal effects such as nausea, diarrhea, vomiting and decreased appetite, with transient heart-rate increases noted in some studies. This information is provided for research context only.

Mazdutide Dosage, Half-Life & Research

Mazdutide (research codes IBI362 / LY3305677) is a once-weekly, lipidated synthetic analog of the gut hormone oxyntomodulin that acts as a dual agonist at the GLP-1 and glucagon receptors.¹ It has been studied in several randomized controlled trials in adults with overweight or obesity, including a positive phase 3 program (GLORY-1).³ Mazdutide injection received marketing approval in China in 2025; it is not an approved drug in Canada or most other jurisdictions and is offered here strictly for research use only (RUO).¹ All figures below describe what investigators reported in published studies and do not constitute usage directions. Note that published chemical descriptors for this CAS number differ between sources (see structure note), so identity values are presented with that caveat.

Structure

Sequence & identity

Lipidated OXM analog (not a simple linear peptide) · C₂₀₇H₃₁₇N₄₅O₆₅ · ~4476 g/mol (PubChem CID 167312357)

Lipidated oxyntomodulin (OXM) analog: a ~39-residue backbone with an Aib substitution and a C19 fatty-diacid attached via an AEEA-AEEA-γGlu spacer at a lysine side chain. Identity per PubChem CID 167312357: molecular formula C₂₀₇H₃₁₇N₄₅O₆₅, molar mass ~4476 g/mol, InChIKey XRBYWQZGSZWYEJ-HMQIFOERSA-N, CAS 2259884-03-0.⁶ Several registry and vendor sources (e.g. Wikipedia, FDA GSRS and chemical suppliers) list the same CAS with a slightly different molecular formula, C₂₁₀H₃₂₂N₄₆O₆₇ (molar mass ~4563.1 g/mol); the discrepancy reflects differences in the deposited or registered structure.⁵

What the research shows

Mechanisms studied

Mazdutide is engineered from mammalian oxyntomodulin to co-activate the GLP-1 receptor and the glucagon receptor.¹ Researchers describe GLP-1 receptor activation as driving appetite suppression and glucose-dependent insulin secretion, while glucagon receptor activation is proposed to raise energy expenditure and reduce hepatic fat; a C19 fatty-diacid moiety prolongs circulation to support once-weekly subcutaneous administration.¹² In the phase 1b study, investigators reported that plasma concentrations declined slowly over several weeks, with an elimination half-life that varied widely across participants (on the order of ~7 to ~45 days), consistent with weekly dosing.²

Reported in studies

Dosing in the research literature

The figures below summarise regimens as reported in published research — they are not recommendations or directions for use.

Source / model	Regimen reported	Notes
Phase 1b MAD trial (Ji et al., eClinicalMedicine 2022)	Once-weekly subcutaneous; 9 mg cohort titrated 3 mg (wk 1-4) → 6 mg (wk 5-8) → 9 mg (wk 9-12); 10 mg cohort titrated 2.5 → 5 → 7.5 → 10 mg over 16 weeks	Regimen as administered to study participants, not a usage directive. At wk 12 the 9 mg group showed -11.7% body weight vs -1.8% placebo; at wk 16 the 10 mg group -9.5% vs -3.3% placebo.²
Phase 2 RCT (Ji et al., Nat Commun 2023)	Once-weekly subcutaneous over 24 weeks; 3 mg (1.5→3), 4.5 mg (1.5→3→4.5), and 6 mg (2→4→6) titration arms; 248 adults randomized	Study-reported only. Week-24 estimated mean body-weight change: -6.7% (3 mg), -10.4% (4.5 mg), -11.3% (6 mg) vs +1.0% placebo.¹
Phase 3 GLORY-1 (NEJM 2025)	Once-weekly subcutaneous 4 mg or 6 mg over 48 weeks in 610 Chinese adults with obesity/overweight + comorbidity	Reported in trial participants, not directions for use. Week-48 mean weight change -12.05% (4 mg) and -14.84% (6 mg) vs -0.47% placebo.³

Research use only. Peptigo products are sold to qualified researchers for laboratory use. This information summarises published research for reference and is not medical advice, a dosing recommendation, or directions for human or animal use.

Reported in studies

Effects observed in research

Across the published RCTs, investigators reported dose-dependent reductions in body weight versus placebo (for example, estimated mean changes of roughly -6.7% to -11.3% at 24 weeks in phase 2 and up to about -14.8% at 48 weeks with the 6 mg dose in GLORY-1).¹³ In GLORY-1, researchers also observed reductions in waist circumference and in liver fat content among participants with elevated baseline hepatic fat, alongside changes in blood pressure, lipids, serum uric acid and transaminases.³ Reported treatment-emergent adverse events were predominantly mild-to-moderate gastrointestinal effects (nausea, diarrhea, vomiting, decreased appetite); transient increases in heart rate were noted in the trials.¹³ These are observations from controlled studies and are not claims of benefit.

Honest assessment

Strength of evidence

Grade A

Grade A. Mazdutide has a mature human evidence base: multiple completed randomized, placebo-controlled trials (phase 1b and phase 2) plus a positive phase 3 trial (GLORY-1) published in The New England Journal of Medicine in 2025, and marketing approval in China.¹²³ Important caveats remain: it is investigational outside China, long-term cardiovascular-outcome data are still limited, and most pivotal data come from Chinese populations.³ The reported elimination half-life derives from early-phase pharmacokinetic work and varied substantially across cohorts.² Sold in Canada for research use only; not for human or veterinary use.

Handling

Reconstitution & storage

Reconstitute with bacteriostatic water for laboratory handling. Store lyophilised material frozen and reconstituted material refrigerated. Use Peptigo’s reconstitution calculator and storage cheat sheet for working figures.

References

Ji L, Jiang H, Bi Y, et al. A phase 2 randomised controlled trial of mazdutide in Chinese overweight adults or adults with obesity. Nat Commun. 2023;14:8289. doi:10.1038/s41467-023-44067-4. https://www.nature.com/articles/s41467-023-44067-4
Ji L, Jiang H, Cheng Z, 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. doi:10.1016/j.eclinm.2022.101691. https://pmc.ncbi.nlm.nih.gov/articles/PMC9561728/
Innovent Biologics / Eli Lilly. Once-weekly mazdutide for overweight or obesity in Chinese adults (GLORY-1). N Engl J Med. 2025. doi:10.1056/NEJMoa2411528. https://www.nejm.org/doi/full/10.1056/NEJMoa2411528
Bhattachar N, Tham LS, Li Y, et al. Mazdutide reduces body weight in adults with overweight or obesity: a high-dose phase 1 trial. Diabetes Obes Metab. 2025. doi:10.1111/dom.70040. https://dom-pubs.onlinelibrary.wiley.com/doi/full/10.1111/dom.70040
Mazdutide. Wikipedia. https://en.wikipedia.org/wiki/Mazdutide (CAS 2259884-03-0; lists formula C210H322N46O67, molar mass ~4563.1 g/mol; approved for marketing in China, 2025)
PubChem. Mazdutide, CID 167312357. National Library of Medicine. https://pubchem.ncbi.nlm.nih.gov/compound/167312357 (molecular formula C207H317N45O65, molar mass ~4476, InChIKey XRBYWQZGSZWYEJ-HMQIFOERSA-N, CAS 2259884-03-0)

Written by the Peptigo Research Team · scientifically reviewed by Peter, Peptigo Research Team · Last reviewed June 2026. We cite primary literature and flag where evidence is limited. Our sourcing & RUO policy →