Selank is a synthetic heptapeptide consisting of seven amino acids with the sequence Thr‑Lys‑Pro‑Arg‑Pro‑Gly‑Pro. It was originally developed by the Institute of Molecular Genetics in Russia as a synthetic analogue of the natural immunoregulatory peptide tuftsin. In research settings, Selank is studied as a neuropeptide with anxiolytic, nootropic, and immune‑modulating properties, including effects on neurotransmitter regulation such as GABAergic, serotonergic, and dopaminergic systems and expression of related genes involved in stress and cognitive function.

Selank is typically supplied as a white lyophilized (freeze‑dried) powder for laboratory research, which must be reconstituted with an appropriate sterile solvent before use. Its chemical composition is described by the molecular formula C₃₃H₅₇N₁₁O₉ and a molecular weight of approximately 751.87 Da.

For storage, Selank should be kept in a cool, dry place. Lyophilized Selank is commonly stored at ‑20 °C or lower to preserve stability over the long term. After reconstitution, peptide solutions should be used promptly or stored refrigerated as recommended and protected from repeated freeze/thaw cycles to maintain integrity.

A Certificate of Analysis (COA) is typically provided by vendors and includes batch/lot number, analytical verification of compound identity, purity (often ≥97–99% as determined by analytical methods such as HPLC), molecular weight confirmation, physical description, and recommended storage conditions.

Selank is intended strictly for research purposes only and is not FDA‑approved for clinical use or human consumption. It is commonly used in preclinical research to investigate peptide‑mediated modulation of neural signaling, stress responses, cognitive pathways, and immune‑related gene expression.