Selank  is a nootropic, anxiolytic peptide based drug developed by the Institute of Molecular Genetics of the Russian Academy of Sciences. Selank is a heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro. It is a synthetic analogue of a human tetrapeptide tuftsin.

Selank is a synthetic analogue of the immunomodulatory peptide tuftsin; as such, it mimics many of its effects. It has been shown to modulate the expression of Interleukin-6 (IL-6) and affect the balance of T helper cell cytokines. It has been shown to influence the concentration of monoamine neurotransmitters and induce metabolism of serotonin. There is evidence that it may also modulate the expression of brain-derived neurotropic factor (BDNF) in rats.

Selank, as well as a related peptide drug, semax, have been found to inhibit enzymes involved in the degradation of enkephalins and other endogenous regulatory peptides, and this action may be involved in their effects.