Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is a synthetic analogue of the endogenous immunomodulatory tetrapeptide tuftsin, extended with a stabilising Pro-Gly-Pro sequence to improve metabolic stability. It was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences and has been approved for clinical use in Russia and Ukraine as an anxiolytic agent.
Unlike benzodiazepines, Selank does not appear to act directly on GABA-A receptors. Instead, research suggests it modulates the expression of BDNF (brain-derived neurotrophic factor) and interacts with enkephalin-degrading enzymes, mechanisms that may underlie its anxiolytic effects without sedation or dependence liability.