What is Retatrutide (LY3437943)? Structure, identifiers and supplied format

Retatrutide (development code LY3437943) is a 39-amino-acid synthetic peptide designed as a single-molecule agonist at three receptors: the GIP receptor (GIPR), the GLP-1 receptor (GLP-1R) and the glucagon receptor (GCGR). Because one molecule is designed to engage three receptors, the research literature often calls it a “triple agonist”. This guide covers its chemical identity, how it is supplied as a research material, and what to check in the documentation.

Retatrutide at a glance

What kind of molecule is Retatrutide?

Retatrutide is a modified peptide rather than a plain chain of the twenty standard amino acids. Published descriptions of the molecule note non-standard residues and a fatty-acid side chain attached to the peptide backbone. Attaching a lipid chain in this way is called lipidation, and it is a common design feature of engineered peptide analogues.

These modifications are why the molecular formula and mass are larger than a simple 39-residue peptide would suggest. They are also why mass confirmation is a useful identity check: the measured mass should be consistent with approximately 4731.3 g/mol.

Why is Retatrutide called a triple agonist?

In receptor pharmacology, peptide analogues in this family are usually grouped by how many receptors they are designed to engage:

Retatrutide sits in the third group. This is a classification by designed receptor target as used in the research literature. It is not a statement about any outcome, and Ascend Research makes no representation regarding physiological effects.

How is Retatrutide supplied by Ascend Research?

Ascend Research supplies Retatrutide as a white lyophilised powder in sealed vials, dispatched from within Australia. One listing covers four vial quantities (10mg, 20mg, 30mg and 60mg). The quantity stated is the amount of material per vial.

Two multi-item listings also include it, each supplied as separate items rather than a premix: the Retatrutide + Bacteriostatic Water Set and the Retatrutide + Cagrilintide Research Duo. Related compounds are grouped under peptide analogues.

What should the documentation show?

• The compound name and batch number match the vial label.
• A purity figure from HPLC (high-performance liquid chromatography).
• A mass spectrometry result consistent with approximately 4731.3 g/mol.
• The appearance of the material (white lyophilised powder).
• The testing laboratory and the date of analysis.

Batch documents are published on the COAs page. For help reading them, see how to read a peptide certificate of analysis.

Frequently asked questions

What is the CAS number for Retatrutide?

The CAS number for Retatrutide is 2381089-83-2.

Is LY3437943 the same compound as Retatrutide?

Yes. LY3437943 is the development code for Retatrutide and is frequently used in the research literature to refer to the same compound.

What is the molecular weight of Retatrutide?

Approximately 4731.3 g/mol, with the molecular formula C221H342N46O68.

How many amino acids are in Retatrutide?

Retatrutide is a 39-amino-acid synthetic peptide that includes non-standard residues and a fatty-acid side chain.

Is Retatrutide supplied premixed with a diluent?

No. It is supplied as a single-compound lyophilised powder. Where a set lists bacteriostatic water, that item is supplied separately.

All Ascend Research products are sold strictly for laboratory research use only. They are not for human or animal use, and nothing in this article is medical advice.

The Ascend Research team