Retatrutide: Peptide Profile, CAS & Properties
CAS 2381089-83-2 · 4731.33 g/mol
Retatrutide (CAS 2381089-83-2) is a 39-amino-acid acylated peptide that acts as a GLP-1, GIP and glucagon triple receptor agonist (molecular formula C221H342N46O68, ~4731.33 g/mol). It is investigational and in Phase 3 clinical development, not approved by any regulator. This page provides reference information on Retatrutide.
- CAS Number
- 2381089-83-2
- Molecular Formula
- C221H342N46O68
- Molecular Weight
- 4731.33 g/mol
- Drug Class
- GLP-1 / GIP / glucagon triple receptor agonist
What is Retatrutide?
Retatrutide is a single-chain synthetic peptide that acts as a triple receptor agonist, simultaneously activating the GLP-1 receptor (GLP-1R), the glucose-dependent insulinotropic polypeptide receptor (GIPR) and the glucagon receptor (GCGR). The 39-amino-acid backbone is acylated with a C20 fatty di-acid moiety attached via a linker at the lysine residue at position 17, which drives albumin binding for an extended half-life and supports once-weekly administration.
Retatrutide (CAS 2381089-83-2, molecular formula C221H342N46O68, ~4731.33 g/mol) is described in the literature as a lyophilised powder. It is an investigational compound currently in Phase 3 clinical development for obesity and type 2 diabetes; it has not been approved by the FDA, EMA or any other regulator for any indication.
How Retatrutide Is Produced & Characterised
Retatrutide is a synthetically demanding multi-agonist peptide: the 39-mer length, the C20 fatty di-acid conjugation at Lys17 and the multiple non-native modifications all create opportunities for deletion sequences, diastereomers and incomplete acylation. Peptides of this class are typically produced by Fmoc solid-phase peptide synthesis (SPPS) with controlled side-chain conjugation, followed by preparative reverse-phase HPLC purification (often using dynamic axial compression columns) to resolve the target sequence from closely related impurities, and final lyophilisation to a stable powder.
Characterisation generally combines UPLC/HPLC for purity with LC-MS for sequence confirmation and impurity profiling. Additional release attributes commonly assessed for acylated peptides include water content, counter-ion (acetate or trifluoroacetate) content, residual solvents and peptide content. This describes the general analytical approach for this peptide class for reference purposes only.
Typical Quality Specifications & Impurity Profile
For a complex acylated peptide such as retatrutide, research-grade and pharmaceutical reference specifications typically target high chromatographic purity (commonly ≥99% by UPLC/HPLC) with tight control of individual related-substance impurities. Closely related species — deletion sequences, diastereomers and incompletely acylated variants — are the principal impurities that purification and analytics are designed to control.
Stability and identity are generally evaluated using ICH-aligned approaches: long-term and accelerated stability studies (ICH Q1A(R2)) and validated analytical methods (ICH Q2(R1)). These are typical, illustrative specifications for the molecular class and are provided here as general educational reference rather than the specification of any particular material.
Regulatory & Development Status
Retatrutide is an investigational active pharmaceutical ingredient. As of its most recent published status it is in Phase 3 clinical development for obesity and type 2 diabetes and has not been approved by the FDA, EMA or any other regulator for any indication. It is not an approved medicine and is not available as a finished pharmaceutical product.
For investigational peptides at this stage, sponsors compiling regulatory submissions generally reference CMC information through mechanisms such as Drug Master Files (e.g. US-DMF Type II) and CTD Module 3, alongside ICH-aligned analytical validation and stability data. This page reflects the molecule's regulatory and development context for informational purposes only and is not medical, dosing or patient guidance.
Retatrutide API — Specifications
| CAS Number | 2381089-83-2 |
|---|---|
| Molecular Formula | C221H342N46O68 |
| Molecular Weight | 4731.33 g/mol |
| Sequence | 39 amino acids, acylated (C20 di-acid side chain at Lys17) |
| Drug Class | GLP-1 / GIP / glucagon triple receptor agonist |
| Regulatory Status | Investigational — Phase 3, not yet approved |
| Appearance | White to off-white lyophilised powder |
| Typical Purity (HPLC) | Commonly reported ≥ 99.0% (single impurity < 0.10%) |
| Synthesis Route | Fmoc SPPS + preparative reverse-phase HPLC purification |
| Form | Lyophilised powder |
Reference data only — WinHyCare neither supplies nor manufactures this compound; see our Semaglutide API for the product we supply. Regulatory status: Investigational; in clinical development (Phase 3) and not yet approved by the FDA, EMA or any regulator for any indication.
Retatrutide API — Frequently Asked Questions
What is Retatrutide?
Retatrutide is a synthetic 39-amino-acid peptide that acts as a triple receptor agonist, simultaneously activating the GLP-1 receptor (GLP-1R), the glucose-dependent insulinotropic polypeptide receptor (GIPR) and the glucagon receptor (GCGR). It is also known by the development code LY3437943.
What is the CAS number and molecular weight of Retatrutide?
Retatrutide's CAS number is 2381089-83-2, its molecular formula is C221H342N46O68, and its molecular weight is approximately 4731.33 g/mol. The 39-amino-acid backbone is acylated with a C20 fatty di-acid side chain at the lysine residue at position 17.
Is Retatrutide approved by the FDA or EMA?
No. Retatrutide is an investigational compound in Phase 3 clinical development for obesity and type 2 diabetes and is not yet approved by the FDA, EMA or any other regulator for any indication. It is not an approved medicine.
What class of peptide is Retatrutide?
Retatrutide belongs to the GLP-1 and incretin multi-agonist class. Specifically, it is a GLP-1 / GIP / glucagon triple receptor agonist — an acylated, long-acting peptide designed for albumin binding and an extended half-life.
What is Retatrutide being studied for?
Retatrutide is being investigated in clinical trials primarily for obesity and type 2 diabetes. This reflects the published research context for the molecule and is not therapeutic, dosing or patient guidance.
What is the mechanism of Retatrutide?
Retatrutide is a triple receptor agonist that simultaneously activates the GLP-1 receptor (GLP-1R), the glucose-dependent insulinotropic polypeptide receptor (GIPR) and the glucagon receptor (GCGR). This describes its molecular pharmacology; it is not therapeutic or dosing guidance.
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Technical Reference Page
WinHyCare neither supplies nor manufactures Retatrutide; this page is provided as a technical reference. The peptide API we supply is Semaglutide.