Selank, which was developed in Russia, is a short peptide with nootropic and anxiolytic properties. It is a synthetic analogue of naturally occurring Tuftsin, an immunomodulatory peptide that modulates IL-6, T helper cells, monoamine neurotransmitters, and brain- derived neurotropic factor (BDNF). In fact, Selank and Tuftsin are essentially the same except that Selank has an additional four amino acids in its chain that help to improve metabolic stability and half-life. Selank has been tested in clinical trials as a potential treatment for generalized anxiety disorder.