Selank

Selank is a synthetic peptide based on tuftsin, a naturally occurring immune-signaling fragment, and was also developed in Russia, primarily as an anti-anxiety agent.

Its proposed calming effect is attributed to several actions: modulating GABA signaling (the brain's main 'brake'), slowing the breakdown of the body's own calming peptides (enkephalins), and influencing BDNF — together producing anxiolytic effects without the dependence typical of sedatives.

As with Semax, the supporting evidence comes largely from a Russian clinical tradition and is limited by Western standards; it is not an approved medication.