Last reviewed: October 2026 · Cleared Peptides research team
Research use only. Mazdutide: Research Guide to the GLP-1 and Glucagon Receptor Peptide is supplied for laboratory research. It is not a drug, food, cosmetic, or dietary supplement. It is not FDA-approved. It is not for human or veterinary administration. This page does not give a dose or a method of administration. A study cited on this page describes that study’s own test article. It does not make this lot an approved medicine. To check a fact, open the PubMed or DOI link, confirm the authors and year, and match the paper’s compound name, CAS number, or sequence to the specification table. The full method is on the research desk page. Identity and purity for a lot are only what that lot’s certificate of analysis reports. An HPLC percentage is not a sterility result and not an endotoxin result unless the certificate prints those tests.
Mazdutide (LY3305677, IBI362) is a synthetic peptide described in public substance records as a GLP-1 receptor and glucagon receptor agonist. CAS 2259884-03-0. Formula C207H317N45O65 is the formula on the public compound record. It is not the same molecule as retatrutide, which is also studied at the GIP receptor.
| Name | Mazdutide |
|---|---|
| Other names | LY3305677; LY-3305677; IBI362 |
| CAS number | 2259884-03-0 |
| Molecular formula | C207H317N45O65 |
| Class | GLP-1 receptor and glucagon receptor peptide |
| Catalog status | Not a current Cleared Peptides lot. |
Receptor class
Retatrutide is described at three receptors: GIP, GLP-1, and glucagon. Mazdutide’s public record is the two-receptor pair GLP-1 and glucagon. Survodutide and cotadutide are separate peptides in that same two-receptor group.
Analytical testing notes for Mazdutide
Mazdutide is identified in this guide as CAS 2259884-03-0, formula C207H317N45O65. An identity test compares a measurement with those values. A mass spectrum is the usual measurement for a peptide. FTIR, when a certificate uses it, is a supporting infrared fingerprint and is less specific for closely related sequences.
Mazdutide carries a fatty-acid or other lipophilic modification, so it is among the later-eluting peptides on a C18 column. Laboratories often raise the acetonitrile fraction, the column temperature, or move to a C8 or C4 column so the main peak is sharp enough to integrate. The mass used for identity has to include the lipid chain and linker, not only the amino-acid backbone. Area-percent purity still ignores water and counterion.
HPLC purity for this material is an area-percent result at the wavelength and gradient the laboratory states, commonly ultraviolet detection near 214 nm on a reversed-phase column. The instrument is a gradient pump, injector, column oven, and UV or diode-array detector. That percentage is not the number of milligrams in the vial. Water, acetate, trifluoroacetate, and other UV-silent material can dominate the gross weight while the purity figure stays high. Net peptide content, from an assay or amino-acid analysis, is the separate result to read when the certificate reports it.
A sterility test and an endotoxin test are not included in a chemical purity result. The compendial sterility test is a culture method (USP <71>): membrane filtration or direct inoculation into fluid thioglycollate medium and soybean-casein digest medium, incubated for 14 days. A PCR sterility screen uses a thermal cycler to detect microbial DNA and is a different method. The endotoxin test (USP <85> LAL, or USP <86> recombinant Factor C) reports endotoxin units with an incubating reader or a cartridge reader. Use a result only when that method is printed on the lot certificate. One published example in this catalog states that the report does not cover microbial contamination or endotoxins. The full description of equipment, standards, and how US laboratory accreditation works is in peptide analytical testing. Lot records are on the COA page.
Frequently Asked Questions
What is the catalog or development code?
LY3305677 and IBI362.
Is mazdutide retatrutide?
No. Different CAS numbers. Retatrutide is CAS 2381089-83-2.
Is this for human use?
No. Laboratory reference only. No dosing is provided.
Selected References
Registry records and peer-reviewed literature listed as scientific background. Citation does not imply endorsement, a benefit, or any use.
- PubChem compound record for mazdutide, CID 167312357, CAS 2259884-03-0. PubChem 167312357
Research Use Only Notice
This guide is provided for educational and laboratory reference purposes. It summarizes published structural and biochemical literature. It does not describe, recommend, or imply any use in humans or animals. These materials are not drugs, foods, cosmetics, or dietary supplements on this page, are not offered here as a treatment, and no dosing or administration instructions are provided. Cleared Peptides does not currently list a lot for every compound on this page.
