Mazdutide

Overview

Mazdutide (development codes IBI362 and LY3305677) is a once-weekly subcutaneous peptide that acts as a dual agonist of the GLP-1 receptor (GLP-1R) and the glucagon receptor (GCGR). It is engineered as an analog of the gut hormone oxyntomodulin, a natural peptide that itself activates both of these receptors. The molecule was in-licensed from Eli Lilly and developed principally by Innovent Biologics for the Chinese market. [Human]

In June 2025, China's National Medical Products Administration (NMPA) approved mazdutide for chronic weight management, and in September 2025 for glycemic control in adults with type 2 diabetes — making it, per the developer, the first dual glucagon/GLP-1 receptor agonist approved for weight loss anywhere. [Human] It is not approved by the US FDA or the EMA as of the sources reviewed (mid-2026).

Chemistry and structure

Mazdutide is a synthetic acylated peptide built on an oxyntomodulin backbone. Secondary sources describe it as a ~30-amino-acid peptide bearing a C20 fatty-diacid (diacid) acyl group attached via a linker at position K20, a lipidation strategy that promotes albumin binding and extends half-life to support once-weekly dosing. The exact verified residue sequence was not confirmed in a primary source (see Unknowns).

There is an unresolved discrepancy in the reported molecular formula and weight between databases, which we report transparently rather than reconcile:

Mechanism of action

• Dual agonism of GLP-1R and GCGR — mazdutide is an engineered oxyntomodulin analog that simultaneously activates the GLP-1 receptor and the glucagon receptor. [Human] (Consistent across the PubChem description, Wikipedia, and the phase 1b/2/3 clinical publications.)
• GLP-1R arm — activation drives appetite suppression, slowed gastric emptying, and glucose-dependent insulin secretion, the established pharmacology of the GLP-1 class, supported by mazdutide's own glycemic and weight-loss trials. [Human]
• GCGR arm — glucagon-receptor activation is proposed to add increased energy expenditure, hepatic fat oxidation/reduction, and lipolysis, complementing the GLP-1 effects. [Hypothesis] (This is the proposed mechanism in reviews and secondary sources; the relative in-human contribution of the glucagon arm was not isolated in the sources reviewed.)

Research and evidence

Multiple completed human trials have been conducted in China. The pivotal data to date are predominantly in Chinese populations.

Human evidence. Unlike most compounds on this site, mazdutide has a substantial human dataset: peer-reviewed phase 1b (overweight/obesity and separately type 2 diabetes), a phase 2 RCT, phase 3 trials (GLORY-1, GLORY-2), and a systematic review/meta-analysis, culminating in two NMPA approvals. Two important caveats remain, honestly stated: (1) the GLORY-1/GLORY-2 endpoint figures here come partly from secondary reporting (press releases / Wikipedia summary) rather than direct reading of the primary phase 3 publication; and (2) the pivotal data are predominantly in Chinese populations, with no FDA/EMA approval and long-term/cardiovascular outcome data not reviewed here.

Status and regulation

• China (NMPA — approved): chronic weight management in adults with overweight/obesity (June 2025) and glycemic control in adults with type 2 diabetes (September 2025). Developed/marketed by Innovent Biologics (licensed from Eli Lilly). A 9 mg supplementary application for moderate-to-severe obesity was reported accepted for review in November 2025.
• United States (FDA) and European Union (EMA): not approved as of the sources reviewed (mid-2026); described as investigational / in additional Phase III studies outside China. Any FDA/EMA filings or activity outside China were not established from the sources reviewed.

Regulatory approval applies only to the specific licensed finished product in the approving jurisdiction. Material sold as a research chemical/reagent is not an approved medicine, and intent for human use would make it an unauthorised medicine. This is not medical or legal advice — verify current status in your jurisdiction.

Safety

• Mazdutide is an incretin/oxyntomodulin-class agent; GLP-1 class pharmacology (appetite suppression, slowed gastric emptying) implies gastrointestinal effects are the expected dominant class tolerability issue, but a detailed adverse-event breakdown was not extracted into the researched facts here.
• Long-term safety and cardiovascular outcome data were not reviewed for this entry.
• The glucagon-receptor arm's net metabolic effects in humans (energy expenditure, hepatic fat) are proposed rather than isolated, so its long-run safety contribution is not independently characterised in the sources reviewed. [Hypothesis]

Legal status

Mazdutide occupies two separate axes that should not be conflated. On the approved-medicine axis, it is a licensed prescription product in China only (NMPA) — that approval does not extend to the FDA, the EMA, or to research-grade material. On the research-reagent axis, any material sold as "research use only" is not an approved medicine: a "no specific ban" status is not affirmative permission, and a compound becomes an unauthorised medicine the moment it is intended for human use outside an approved product.

WADA status: Not established. No source reviewed asserts a WADA Prohibited-List class code for mazdutide, and "unapproved (in a given market) ⇒ prohibited in sport" is an invalid inference — WADA sport-eligibility is a separate axis from legality. Do not read a class code into this entry.

This is a regulatory/scientific summary dated 2026-07-08 and is not legal advice. Laws and approvals differ by country and change over time — verify the current status in your jurisdiction.

How it compares

Mazdutide sits in the incretin-based metabolic class alongside other multi-receptor agents documented here:

• Tirzepatide — an FDA/EMA-approved dual GIP/GLP-1 agonist. Mazdutide's second target is the glucagon receptor (GCGR), not GIP, and its approval is China-only.
• Retatrutide — an investigational triple GIP/GLP-1/glucagon agonist; it adds GIP on top of the two receptors mazdutide targets, and is not approved by any regulator.
• Semaglutide and Cagrilintide are further points of reference within the broader weight-management landscape.

Comparisons across separate trials and populations should be read cautiously; doses, durations, and study populations differ, and mazdutide's pivotal data are predominantly Chinese.

Common misconceptions

• "Mazdutide is FDA/EMA-approved." It is not. Its approvals are China-only (NMPA), for chronic weight management and type 2 diabetes.
• "It's just another GLP-1 drug." It is a dual GLP-1 / glucagon receptor agonist (an oxyntomodulin analog) — the glucagon arm is what distinguishes it from single-receptor GLP-1 agents.
• "The glucagon arm is proven to drive fat loss in people." The glucagon-receptor contribution (energy expenditure, hepatic fat) is a hypothesis/proposed mechanism; its relative in-human contribution was not isolated in the sources reviewed. [Hypothesis]
• "Research-grade 'mazdutide' is the approved drug." It is not. The China approval covers a specific finished product; unregulated material lacks identity, purity, and potency controls and is not an approved medicine.

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This entry is educational and summarizes published trial data and public regulatory information. It is not medical advice, a recommendation, or a guide to obtaining or using any substance.