Compound profile

Retatrutide

Retatrutide (LY3437943) is a synthetic, lipidated single-chain peptide that functions in vitro as a triple agonist of the GIP, GLP-1, and glucagon receptors. It is supplied as a research reference compound for receptor-binding and signaling assays.

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What it is

Retatrutide is a 39-residue synthetic peptide structurally derived from the glucagon/incretin receptor-ligand family. Its backbone incorporates several non-coded modifications that distinguish it from native incretin-family peptides: alpha-aminoisobutyric acid (Aib) substitutions at positions 2 and 20, an alpha-methyl-leucine at position 13, and a C-terminal amide. A lysine residue within the sequence is conjugated through an AEEA spacer and a gamma-glutamate linker to a C20 fatty diacid, a lipidation motif that facilitates reversible albumin association and contributes to the molecule's in-vitro and in-solution stability. The compound is also referenced by its developmental code LY3437943. As a defined synthetic peptide of known mass and sequence, it is used strictly as an in-vitro biochemical reference standard.

Mechanism (in-vitro research context)

In receptor-binding and cell-based reporter assays, Retatrutide engages three class B G-protein-coupled receptors: the GIP receptor (GIPR; glucose-dependent insulinotropic polypeptide receptor), the GLP-1 receptor (GLP-1R), and the glucagon receptor (GCGR). Agonism at these receptors couples to Gs and stimulates adenylate cyclase, producing intracellular cAMP accumulation that is commonly quantified in cAMP-response-element (CRE) luciferase reporter or HTRF cAMP assays. Published in-vitro characterization reports half-maximal effective concentrations (EC50) in the low-nanomolar to sub-nanomolar range across the three receptors, with relative potency differing by receptor subtype. These properties make the peptide a useful tool compound for comparative GPCR pharmacology, receptor-selectivity profiling, and signal-transduction studies.

Research areas

GPCR receptor-binding and competition assays at GIPR, GLP-1R, and GCGR
cAMP accumulation and CRE-luciferase reporter signaling assays in receptor-transfected cell lines
Comparative agonist potency (EC50) and receptor-selectivity profiling among incretin-family peptides
Beta-arrestin recruitment and receptor internalization assay development
Structure-activity studies of lipidated, Aib-substituted peptide analogs
Analytical method development for peptide identity and purity (HPLC, LC-MS)

Chemistry

Molecular weight: 4731.4 g/mol
CAS: 2381089-83-2
Formula: C221H342N46O68
Sequence: Tyr-Aib-Gln-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-(alpha-Me-Leu)-Leu-Asp-Lys-Lys(AEEA-AEEA-gamma-Glu-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

Laboratory handling

For laboratory handling, the lyophilized peptide is typically stored desiccated at -20 C, with -80 C preferred for extended archival storage, and protected from light and moisture. Reconstituted stock solutions in an appropriate aqueous or buffered vehicle are generally aliquoted to minimize repeated freeze-thaw cycles, which can degrade peptide integrity. Analytical stability and identity are confirmed by HPLC and mass spectrometry; solutions should be evaluated for purity before use in quantitative assays. All handling framing here pertains solely to bench stability of a research reference material.

FAQ

What is the amino acid sequence of Retatrutide?

It is a 39-residue C-terminally amidated peptide whose backbone reads Tyr-Aib-Gln-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Ile-(alpha-Me-Leu)-Leu-Asp-Lys-Lys-Ala-Gln-Aib-Ala-Phe-Ile-Glu-Tyr-Leu-Leu-Glu-Gly-Gly-Pro-Ser-Ser-Gly-Ala-Pro-Pro-Pro-Ser-NH2, with non-coded Aib residues at positions 2 and 20, alpha-methyl-leucine at position 13, and a lysine bearing an AEEA/gamma-Glu-linked C20 fatty diacid.

What receptors does Retatrutide act on in vitro?

In cell-based assays it is a triple agonist of three class B GPCRs: the GIP receptor (GIPR), the GLP-1 receptor (GLP-1R), and the glucagon receptor (GCGR), each coupling to cAMP signaling.

What is its molecular weight and formula?

The reported molecular weight is approximately 4731.4 g/mol with the molecular formula C221H342N46O68; its CAS number is 2381089-83-2.

How is purity verified?

Identity and purity are typically assessed by reversed-phase HPLC for chromatographic purity and by mass spectrometry (LC-MS) to confirm the expected monoisotopic/average mass of the modified peptide.

How should it be stored in the laboratory?

The lyophilized solid is best kept desiccated at -20 C (or -80 C for long-term archival), protected from light and moisture; reconstituted aliquots should avoid repeated freeze-thaw cycles to preserve analytical integrity.

References

Research-use only

For laboratory research use only. Not for human or veterinary use. Not for diagnostic or therapeutic use. These products have not been approved or evaluated by the U.S. Food and Drug Administration. No statement on this site has been evaluated by the FDA. These products are not intended to diagnose, treat, cure, mitigate, or prevent any disease, and are not intended for human or veterinary use. See our research-use terms and terms of service.