NA Selank (N-Acetyl Selank) is an acetylated derivative of Selank, a synthetic heptapeptide anxiolytic developed from the endogenous tuftsin sequence. The N-acetyl modification improves metabolic stability relative to the parent peptide. Like Selank, NA Selank is studied for its anxiolytic, nootropic, and immunomodulatory properties, with research suggesting modulation of GABA receptor sensitivity, BDNF expression, and enkephalin metabolism. It has been examined in research models of chronic stress, anxiety, and cognitive impairment, and is considered one of the more selective peptidergic anxiolytics without the sedative profile of classical benzodiazepines.