What is RETATRUTIDE (RETA)?
Retatrutide (RETA), identified by CAS number 2381089-83-2, is a synthetic single-chain peptide belonging to the class of multi-agonist incretin analogs. It is structurally engineered as a triple agonist designed to interact with three distinct receptor targets: the glucose-dependent insulinotropic polypeptide (GIP) receptor, the glucagon-like peptide-1 (GLP-1) receptor, and the glucagon receptor. Within research nomenclature it is grouped with GLP-1 receptor agonist peptides, and it is studied in in-vitro and preclinical metabolic-research models where multi-receptor incretin signaling is the subject of investigation.
The molecule comprises 39 amino acid residues and incorporates several non-canonical structural features that distinguish it from native incretin hormones. These include α-aminoisobutyric acid (Aib) substitutions and an α-methyl-leucine (α-Me-Leu) residue, both of which are backbone-modifying elements associated with conformational constraint and resistance to enzymatic cleavage in the peptide chemistry literature. The sequence terminates in a C-terminal serinamide, and the chain carries a lysine-conjugated fatty-acid moiety consisting of an (AEEA)-γGlu linker attached to a C20 diacid. This lipidation motif is a common design element among long-acting peptide research analogs.
As a lipid-modified, structurally constrained peptide, Retatrutide is characterized in the laboratory by its primary sequence, its conjugated fatty-diacid side chain, and its overall molecular architecture rather than by any biological outcome. This material is offered strictly as a reference chemical for laboratory research use only. It is not a drug, food, or cosmetic, and it is not intended for human or veterinary use, diagnostic application, or any form of administration.
Reconstitution & handling
Retatrutide is supplied as a lyophilized (freeze-dried) powder that must be reconstituted before use in an in-vitro research setting. As a lipidated peptide bearing a C20 diacid side chain, it is typically brought into solution with bacteriostatic or sterile water; a small fraction of dilute basic buffer is sometimes used by researchers to assist dissolution of amphiphilic, fatty-acid-conjugated sequences. The reconstitution solvent should be directed gently against the wall of the vial rather than injected forcefully onto the powder, and the vial should be allowed to stand and dissolve without vigorous shaking, since mechanical agitation can promote foaming and shear stress on the peptide backbone. Gentle swirling until the solution is clear and free of visible particulates is the standard handling practice.
Solubility behavior reflects the compound's amphipathic character: the hydrophilic peptide chain confers aqueous compatibility while the lipophilic C20 diacid tail can influence dissolution kinetics and apparent clarity. Reconstituted material should be kept in a low-binding container, handled under clean conditions, and protected from repeated warming. This information describes only the physical chemistry of dissolving and handling the reference material and does not constitute any guidance on use, quantity, or administration.
Storage & stability
In its lyophilized form, Retatrutide is best preserved as a sealed, desiccated solid stored frozen, typically at -20 degrees C or colder, and protected from light and moisture; under these conditions the dry peptide is generally regarded as stable for extended periods. Exposure to ambient humidity, heat, and light should be minimized, and vials should be allowed to equilibrate to room temperature before opening to reduce condensation on the cold powder. Once reconstituted, the peptide is less stable and should be held refrigerated (approximately 2 to 8 degrees C) for short-term laboratory handling, with aliquoting recommended to avoid repeated freeze-thaw cycles that can degrade lipidated peptides and promote aggregation. Long-term storage of solutions, where required, is performed frozen. Storage and stability parameters describe preservation of the research material only.
How it's tested
Each lot of Retatrutide is characterized by orthogonal analytical methods to confirm identity and purity, with results documented on a Certificate of Analysis (COA) available for the material. Chromatographic purity is determined by reversed-phase high-performance liquid chromatography (RP-HPLC), which resolves the target peptide from sequence-related and process impurities and supports the stated specification of ≥99% purity. Molecular identity is confirmed by mass spectrometry (MS), commonly electrospray-ionization MS, which verifies the observed molecular mass of the intact lipidated 39-residue peptide against its theoretical value. Complementary tests such as appearance, and where applicable water content and peptide content, may accompany the COA. Reviewing the accompanying COA is the recommended way to verify the composition and quality of a specific lot prior to laboratory work.