Chemical Identity
| Name | Retatrutide (LY3437943) |
|---|---|
| Synonyms | LY3437943, LY-3437943 |
| CAS Number | 2381089-83-2 |
| Molecular Formula | C221H342N46O68 |
| Molecular Weight | 4731.33 g/mol |
| Sequence | Tyr-Aib-Gln-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-αMeLeu-Leu-Asp-Lys-Lys(γGlu-AEEA-C20 diacid)-Ala-Gln-Aib-Ala-Phe-Ile-Glu-Tyr-Leu-Leu-Glu-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2 |
| Structure Class | 39-residue linear peptide with Aib at positions 2 and 20, α-methyl-leucine at position 13 and a C20 fatty diacid on Lys17 via a γGlu–AEEA linker; C-terminal amide |
Mechanisms at a Glance
- Full agonist at the GIP, GLP-1 and glucagon receptors; published potency is highest at GIP, with EC50 figures differing between sources
- Aib residues at positions 2 and 20 and an α-methyl-leucine at 13 resist enzymatic cleavage
- A C20 fatty diacid on Lys17, attached through a γGlu–AEEA linker, binds albumin reversibly for a multi-day half-life
- The glucagon arm is the structural difference from dual GIP/GLP-1 agonists such as tirzepatide, and has been associated in animal work with increased energy expenditure
Research Applications
- Comparative studies of single, dual and triple incretin receptor activation
- Receptor-binding and signalling assays separating GIP, GLP-1 and glucagon contributions
- Analytical reference material for HPLC and LC-MS method development
Handling & Storage
Store lyophilized material at −20 °C, desiccated and protected from light; after reconstitution, keep solutions at 2–8 °C and use within 28 days. See our storage and stability guide and reconstitution guide for technique and diluent selection.
Regulatory Status
Retatrutide is an investigational compound and is not approved by the FDA as a drug for any indication. Material supplied by Aclopiel is strictly for in-vitro laboratory research and is not for human or veterinary use.
Frequently Asked Questions
What is Retatrutide?
Retatrutide is a 39-residue synthetic peptide that activates three receptors at once — GIP, GLP-1 and glucagon — making it the most studied of the triple incretin agonists. There is no GLP-3 receptor, despite the supplier shorthand it is sometimes sold under.
What is the CAS number of Retatrutide?
Retatrutide is registered under CAS number 2381089-83-2. Its molecular formula is C221H342N46O68 and its molecular weight is 4731.33 g/mol.
How should Retatrutide be stored?
Store lyophilized Retatrutide at −20 °C, desiccated and protected from light. After reconstitution, keep it at 2–8 °C and use it within 28 days.
Is Retatrutide approved for human use?
Retatrutide is an investigational compound and is not approved by the FDA as a drug for any indication. Aclopiel supplies it strictly for in-vitro laboratory research; it is not for human or veterinary use.
Is retatrutide a GLP-3 agonist?
No. There is no GLP-3 receptor. Retatrutide is a triple agonist at the GIP, GLP-1 and glucagon receptors, and some suppliers label it “GLP-3 RT” as an internal shorthand for a third-generation incretin rather than as a pharmacological description.
How does retatrutide differ from tirzepatide?
Tirzepatide activates two receptors, GIP and GLP-1. Retatrutide adds a third, the glucagon receptor, and is a longer peptide at 39 residues against tirzepatide's 39-residue GIP-based backbone with different substitutions.
Why do published molecular weights differ?
Most suppliers report 4731.33 g/mol while at least one reports 4732.09. The difference is a rounding or calculation convention rather than a different molecule; confirm against the batch certificate.
Alternative Designations & Synonyms
Retatrutide also appears in the literature and supplier listings under the following names and codes:
- LY3437943
- LY-3437943
- GLP-3 RT
- Triple G agonist
- GGG tri-agonist
References
Coskun T et al., Cell Metab 2022; Jastreboff AM et al., N Engl J Med 2023;389:514-526; Doggrell SA, Expert Opin Investig Drugs 2023; structural analysis in Nat Commun 2024 (PMC11255275).