Mazdutide is an acylated dual GLP-1 and glucagon receptor agonist built on an oxyntomodulin template, cited as IBI362 and LY3305677 in the research literature. What distinguishes it from other glucagon-containing duals is its starting point: oxyntomodulin is a naturally occurring proglucagon product that already activates both receptors, so mazdutide is an engineered version of an existing dual agonist rather than a mono-agonist retrofitted with a second activity. We supply research-grade mazdutide as lyophilized powder in sealed vials, for laboratory use only.
Mazdutide is investigational and holds no marketing approval as of 2026. Research-grade material is a reference chemical, not a medicine, and nothing here is a human protocol.
What is mazdutide, precisely
Proglucagon is processed differently in different tissues. In pancreatic alpha cells it yields glucagon; in intestinal L-cells it yields GLP-1, GLP-2 and oxyntomodulin. Oxyntomodulin is glucagon extended by an eight-residue C-terminal tail, and that extension shifts its receptor profile so that it activates both the GLP-1 and glucagon receptors — weakly at each, and with a half-life of minutes, but genuinely at both. Endogenous dual agonism therefore already exists in human physiology, and mazdutide is the attempt to make it durable and potent enough to study.
The engineering follows the standard playbook for this class: protease-resistant substitutions to defeat dipeptidyl peptidase-4, and a lipid side chain for reversible albumin binding. Catalog identifiers are CAS 2259884-42-1, with the compound also appearing as IBI362 and LY3305677. Molecular weight is not listed on our specification sheet, so laboratories needing an exact mass for molar calculations should work from the lot certificate.
Origin and structure
- Backbone. Oxyntomodulin-derived, meaning a glucagon core plus the C-terminal extension that confers GLP-1 receptor affinity.
- Protease resistance. Substitutions near the N-terminus block DPP-4 cleavage, the vulnerability that limits every native proglucagon product to a few minutes of activity.
- Lipid acylation. A fatty-acid side chain attached through a spacer promotes albumin binding, extending circulating persistence into a multi-day range in published pharmacokinetic work.
- Reported receptor balance. Characterisation describes mazdutide as GLP-1-receptor-weighted with a lower but pharmacologically meaningful contribution from the glucagon receptor.
How mazdutide is thought to work
Both receptors are class B G-protein-coupled receptors that raise cAMP through Gs, but they occupy different tissues and produce different physiology. GLP-1 receptor engagement in islet preparations amplifies insulin secretion in a glucose-dependent manner, and hindbrain, hypothalamic and vagal receptor populations are implicated in the reduced food intake and slowed gastric transit reported in rodent studies. Glucagon receptor engagement acts most prominently on hepatocytes, where published work describes increased fatty-acid oxidation and altered hepatic lipid handling, alongside raised whole-body energy expenditure in preclinical models.
The class rationale is that the two arms cancel where they conflict and add where they align: incretin-driven, glucose-dependent insulin secretion offsets the hepatic glucose output that glucagon receptor agonism would otherwise cause, while the energy-expenditure component of the glucagon arm is retained. Because oxyntomodulin-based molecules inherit a receptor balance that evolved rather than one designed from scratch, they are often used in the literature as a physiological reference point against which purpose-built duals are compared.
What research has examined
- Receptor and cell studies. cAMP potency and binding assays at human GCGR and GLP-1R in recombinant systems to establish the activity ratio, plus signalling profile work including beta-arrestin recruitment.
- Rodent studies. Food intake and body composition in diet-induced obesity models, indirect calorimetry examining the expenditure component attributable to the glucagon arm, and hepatic lipid content in steatosis models.
- Human clinical trials. Phase 2 and phase 3 data have been published, with a substantial part of the programme conducted in Chinese populations — a detail worth noting when comparing results across the class, because trial population and background metabolic phenotype are not interchangeable variables. These trials describe an investigational pharmaceutical under clinical supervision and say nothing about research-grade powder.
For where mazdutide sits relative to the rest of the field, see our survey of the next generation of GLP-1 molecules and the incretin pathway hub.
One design caution recurs across the glucagon-containing duals. Glucagon receptor pharmacology is less conserved between species than GLP-1 receptor pharmacology, so a potency ratio measured at rodent receptors should not be assumed to reproduce at human ones. Studies attributing an effect to the glucagon arm are considerably stronger when they include a glucagon receptor antagonist arm or a GLP-1 mono-agonist such as semaglutide as a comparator; without one, the observation is indistinguishable from a stronger incretin effect at higher receptor occupancy.
A practical consideration for anyone choosing between the glucagon-containing duals: the useful experimental variable is the receptor ratio, not the molecule name. Two compounds that both engage GLP-1 and glucagon receptors can behave very differently if one is weighted ten-fold further toward the incretin arm, and that ratio is assay-dependent — cAMP potency in a recombinant overexpression line does not necessarily reproduce in a primary hepatocyte with native receptor density. When a study design depends on the balance between arms, the honest approach is to measure the ratio in your own system rather than importing a published figure obtained in a different one. Where the goal is simply a physiologically derived dual agonist reference, mazdutide is the reasonable default because its balance descends from oxyntomodulin rather than from an optimisation target.
Forms and sizes we supply
| Attribute | Specification |
|---|---|
| Form | Lyophilized powder, sealed glass vial with flip-off seal |
| Sizes | 5 mg, 10 mg, 20 mg |
| Purity | Greater than or equal to 99% by HPLC, lot-matched COA |
| CAS | 2259884-42-1 |
| Also cited as | IBI362, LY3305677 |
| Class | Acylated oxyntomodulin analog; dual GLP-1 / glucagon receptor agonist |
| Solubility | Bacteriostatic water; dilute alkaline or phosphate buffers also used |
| Intended use | Laboratory research only |
Sizes and current pricing are on the mazdutide product page, listed within the GLP-1 and incretin peptides collection.
Reconstitution and storage in a lab context
The calculation is arithmetic, not instruction: a 20 mg vial reconstituted with 4 mL of bacteriostatic water yields 5 mg/mL, equal to 5,000 mcg/mL, so 0.2 mL of that solution carries 1,000 mcg of peptide. Where an assay requires a defined buffer instead, dilute alkaline or phosphate systems are commonly used for this class; confirm compatibility with your detection chemistry first.
Add diluent gently down the vial wall, swirl rather than shake, and check for complete clarity before use. Sealed lyophilized material keeps at minus 20 degrees Celsius, protected from light and moisture; reconstituted solution is held at 2 to 8 degrees Celsius, protected from light, and used within the study window. Aliquot at reconstitution so repeated freeze-thaw rounds do not erode the stock. See our reconstitution guide.
Purity, COA and how to read it
A mazdutide certificate should carry an HPLC chromatogram with main-peak area percentage, a mass spectrometry identity result, net peptide content, lot number and analysis date. Identity confirmation deserves particular attention with this molecule for two reasons: the glucagon-containing duals resemble one another structurally, and mazdutide circulates in the literature under three different names, which makes cross-referencing a supplier claim against a published characterisation harder than it should be. Where our specification sheet does not state a molecular weight, treat the lot certificate as authoritative for molar work. See how to read a COA.
The practical upshot for procurement is that molecules in this class are not interchangeable inputs. Two glucagon-containing duals ordered at the same nominal purity can produce different results in the same assay because their receptor ratios differ, and neither result is wrong. Recording which compound, which lot and which certificate underlies a data set is therefore not administrative overhead but part of the experimental record, and it is the only thing that makes a result reproducible by another laboratory working from the same published description.
Regulatory status
Mazdutide has no marketing approval in the United States as of 2026 and remains investigational. Regulatory status differs by jurisdiction for molecules with regionally concentrated trial programmes, and a filing or approval elsewhere does not change the status of research-grade material here. Research-grade mazdutide is supplied as a laboratory reference chemical, labelled research use only, not approved or formulated for human or veterinary administration — see research use only, explained.
Related peptides and comparisons
The direct structural comparator is survodutide, the other glucagon-containing dual in our range, examined in survodutide vs mazdutide. For a triple agonist that adds GIP to the same pair see retatrutide; for the GIP-containing dual, tirzepatide.