Selank (likely intended as "Selenak") is a synthetic 7-amino acid heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) and an analog of the naturally occurring immunomodulatory peptide tuftsin.

It was developed in the 1990s–early 2000s by the Institute of Molecular Genetics of the Russian Academy of Sciences (in collaboration with the V.V. Zakusov Institute of Pharmacology).

Researchers have investigated Selank in preclinical and clinical models for its anxiolytic (anti-anxiety), nootropic (cognitive-enhancing), and immunomodulatory effects. 

Studies have explored its potential in generalized anxiety disorder, neurasthenia, stress-related conditions, neuroprotection, immune regulation, and enhancement of learning, memory, and adaptive behavior without sedative or muscle-relaxant side effects.