What is SEMAGLUTIDE?
Semaglutide is a synthetic peptide classified as a glucagon-like peptide-1 (GLP-1) receptor agonist analog. Structurally it is a 31-amino-acid single-chain peptide modeled on the native GLP-1 backbone, with a molecular formula of C187H291N45O59 and a molecular weight of 4113.58 g/mol. It is cataloged under CAS number 910463-68-2 and terminates in a C-terminal carboxylate.
The molecule incorporates two defining structural modifications relative to native GLP-1. Position 2 carries 2-aminoisobutyric acid (Aib), a non-proteinogenic, alpha-methylated residue that sterically shields the adjacent peptide bond. The lysine at position 26 is conjugated to a lipophilic C18 diacid moiety through a linker composed of a gamma-glutamate spacer and two 8-amino-3,6-dioxaoctanoic acid (AEEA) units. This acylation architecture is characteristic of long-acting GLP-1 analogs and is the feature that distinguishes semaglutide from the unmodified parent sequence.
As a research material, semaglutide is associated with the study of GLP-1 receptor signaling and incretin biology in in-vitro and preclinical model systems. It is used by qualified laboratories as a reference peptide and biochemical tool for receptor-binding, structure-activity, and analytical method work. This product is intended strictly for laboratory research use only and is not a drug, supplement, or article for human or veterinary use.
Reconstitution & handling
Semaglutide is supplied as a lyophilized powder and is reconstituted by dissolving the solid in an appropriate aqueous solvent, most commonly bacteriostatic or sterile water for laboratory preparations. Because the peptide combines a hydrophilic backbone with a lipophilic C18 diacid side chain, it is amphiphilic; the solvent should be added slowly down the side of the vial and allowed to solubilize with gentle swirling rather than vigorous shaking or vortexing, which can promote foaming and mechanical stress at the air-liquid interface. Brief, gentle agitation and short equilibration at room temperature generally yield a clear solution.
The reconstituted material should be visually inspected for clarity and the absence of particulates before use. Solubility can be sensitive to solution pH and ionic strength; for buffer-based work, a mildly alkaline to neutral aqueous buffer typically improves dissolution of acylated GLP-1 analogs. Prepared solutions should be handled aseptically, kept cold during use, and aliquoted to minimize repeated handling of the working stock. This section addresses dissolution chemistry only.
Storage & stability
In lyophilized form, semaglutide is best stored sealed and protected from light and moisture; short-term storage may be at refrigerated temperatures, while long-term storage of the dry powder is generally at -20 C or colder, where the peptide remains stable for extended periods. Once reconstituted, the peptide is less stable and should be kept refrigerated at 2-8 C for near-term use or held at -20 C for longer intervals; aliquoting before freezing is recommended to avoid repeated freeze-thaw cycles, which can degrade peptide integrity. Minimizing exposure to light, heat, and prolonged time at room temperature helps preserve the material over its usable life.
How it's tested
Identity and purity are verified by orthogonal analytical methods. Reverse-phase high-performance liquid chromatography (HPLC) is used to quantify chromatographic purity, with this lot characterized at greater than or equal to 99% by HPLC. Mass spectrometry (MS) confirms molecular identity by matching the observed mass against the expected molecular weight of 4113.58 for the C187H291N45O59 composition, while the defined 31-residue sequence—including the Aib substitution and the Lys26 diacid conjugation—establishes structural identity. Each batch is accompanied by a Certificate of Analysis (COA) documenting the analytical results for that specific lot.