What is SELANK NASAL SPRAY?
Selank is a synthetic peptide belonging to the class of short, proline-rich regulatory oligopeptides. It is classified as a heptapeptide, meaning its primary structure comprises seven amino acid residues joined by peptide bonds. Its defined sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro, corresponding to the molecular formula C33H57N11O9 and a molecular weight of 751.89. The compound is registered under CAS number 129954-34-3.
Structurally, Selank is characterized by its high proline content, with three of its seven residues (positions 3, 5, and 7) being proline. This proline-rich composition constrains backbone flexibility and yields a compact, conformationally restricted molecule, a feature shared by several naturally occurring regulatory peptides. The sequence also carries basic residues (lysine and arginine) alongside polar threonine and glycine, which render the peptide strongly hydrophilic and readily soluble in aqueous media, a property relevant to its formulation as a nasal spray solution.
Selank is studied within the neuropeptide and peptide-chemistry research areas, where synthetic proline-rich peptides serve as model compounds for investigating peptide stability, receptor-binding chemistry, and structure-activity relationships in vitro. This material is offered strictly as a research reference standard for laboratory investigation and analytical work. It is not a drug, supplement, or article intended for human or veterinary use, and no physiological or therapeutic properties are represented here.
Reconstitution & handling
In its nasal spray presentation, Selank is typically supplied as an aqueous solution, and where a lyophilized reference is reconstituted, bacteriostatic or sterile water is the conventional solvent owing to the peptide's high aqueous solubility. The basic lysine and arginine residues, together with the polar threonine and glycine residues, make the molecule strongly hydrophilic, so it dissolves readily in water-based buffers without the need for organic co-solvents. When reconstituting lyophilized material, the diluent should be added slowly against the vial wall and the solution allowed to dissolve by gentle swirling rather than vigorous agitation or vortexing, since mechanical shear and foaming can promote peptide degradation.
Handling should be performed under clean conditions to minimize microbial and enzymatic contamination, and the reconstituted solution should be kept sealed and chilled between uses. To preserve the peptide in solution, avoid repeated warming and re-cooling; preparing working aliquots limits the number of times the stock is opened and temperature-cycled.
Storage & stability
Lyophilized Selank is most stable stored desiccated at −20 °C, protected from light and moisture, where the dry powder retains integrity over extended periods. Once placed into solution—as in the nasal spray format—the peptide is less stable and should be refrigerated at 2–8 °C for short-term use and held at −20 °C for longer-term storage, ideally in single-use aliquots to avoid repeated freeze-thaw cycles that can accelerate hydrolysis and aggregation. Solutions should be kept in tightly sealed containers away from light and elevated temperatures, and any change in clarity, color, or the appearance of particulates should be treated as a sign of degradation.
How it's tested
Identity and purity of Selank are established by reversed-phase high-performance liquid chromatography (HPLC), which resolves the target heptapeptide from process-related impurities and confirms a purity of ≥99%. Molecular identity is corroborated by mass spectrometry (MS), where the observed mass is compared against the theoretical monoisotopic and average masses derived from the C33H57N11O9 formula and molecular weight of 751.89. Each lot is accompanied by a Certificate of Analysis (COA) documenting the analytical results, including chromatographic purity and mass confirmation, so that researchers can verify the material against its specification before use.