Definition
Retatrutide is a synthetic, lipidated 39-amino-acid research peptide identified as LY3437943 (CAS 2381089-83-2). It is studied as a single-molecule agonist of GLP-1, GIP, and glucagon receptors. Synonyms include Reta.
Fatty-acid acylation supports albumin binding and an extended half-life described in clinical pharmacology literature (on the order of about 6 days). That profile informed weekly schedules in formal trials of the investigational drug candidate. Research reagents sold for laboratory use are not medicines.
PubChem: CID 171390338
Key Facts
- Product: Reta GLP-3
- Compound: Retatrutide (LY3437943; synonym: Reta)
- CAS: 2381089-83-2
- Purity: ≥99% HPLC; authentic batch COA
- Sizes: 10 mg, 20 mg, 30 mg
- Use: Laboratory research only
Last reviewed: 2026-10-14
Key Characteristics
MOLECULAR PROFILE
Formula: C221H342N46O68
Weight: ~4731 g/mol
CAS: 2381089-83-2
Synonyms: Retatrutide; Reta; LY3437943
PHYSICAL PROPERTIES
Form: White to off-white lyophilized powder
Solubility: Soluble in bacteriostatic water or sterile lab-grade water
Stability: Stable when stored dry, cold, and protected from light
Storage: -20°C preferred (lyophilized); 2-8°C after reconstitution
Mechanism of Action (Research Context)
Retatrutide is investigated as a triple agonist. GLP-1 and GIP pathways relate to incretin signaling in appetite-regulation assays, gastric emptying models, and glucose-handling studies. Glucagon-receptor activity is the distinguishing third arm, studied for energy expenditure, lipolysis, and hepatic lipid handling relative to dual agonists.
Findings from clinical trials of the investigational candidate do not transfer to research reagents and do not imply suitability for human use.
Class Comparison: Semaglutide vs Tirzepatide vs Retatrutide
| Feature | Semaglutide (class) | Tirzepatide (class) | Retatrutide |
|---|---|---|---|
| Agonist type | Single (GLP-1) | Dual (GLP-1 + GIP) | Triple (GLP-1 + GIP + glucagon) |
| Primary research focus | Appetite and glucose pathways | Dual incretin pathways | Incretin plus glucagon and energy-expenditure pathways |
| Regulatory note | Approved medicines exist in this class. Research reagents are not medicines. | Approved medicines exist in this class. Research reagents are not medicines. | Investigational. Not FDA-approved. Research supply is not a medicine. |
Scientific orientation only. Prescription medicines and research reagents are not interchangeable.
Research Applications
- Body-weight and energy-balance models (including Phase 2 obesity research literature)
- Glycemic and metabolic markers in type 2 diabetes-related clinical research literature
- Hepatic fat / MASLD-related endpoints in Phase 2a research literature
- Multi-receptor pharmacology in preclinical systems
Laboratory Notes
High-level handling notes for Retatrutide (sold as Reta GLP-3). Detailed reconstitution steps live on the Reta GLP-3 product page. Always defer to your lab SOP and batch COA.
Scientific References
- Jastreboff AM, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity: A Phase 2 Trial. N Engl J Med. 2023;389:514-526.
- Rosenstock J, et al. Retatrutide phase 2 trial in type 2 diabetes. Lancet. 2023.
- Urva S, et al. LY3437943 phase 1b trial. Lancet. 2022;400:1869-1881.
- Coskun T, et al. LY3437943 triple receptor agonist. Cell Metab. 2022.
- Sanyal AJ, et al. Retatrutide for MASLD phase 2a. Nat Med. 2024.
- PubChem. Retatrutide. CID 171390338.
Buy Research-Grade Material
Buy Reta GLP-3 (Retatrutide) from Osae Research (sizes, COA, shipping).
Legal Disclaimer
Content is for scientific orientation. Materials from Osae Research are for laboratory research only. Not for human or veterinary use. Not intended to diagnose, treat, cure, or prevent any disease.