Selank

Selank (TP-7; CAS 129954-34-3; MW 751.9 g/mol; sequence TKPRPGP) is a synthetic 7-amino acid heptapeptide developed by the Institute of Molecular Genetics of the Russian Academy of Sciences as an analog of tuftsin, an endogenous 4-amino acid immunomodulatory peptide found in IgG antibodies. The design added a C-terminal Pro-Gly-Pro tripeptide extension to tuftsin's natural TKPR sequence — preserving the parent peptide's biological activities while conferring resistance to enzymatic degradation that would otherwise severely limit effective half-life.

Selank is approved as an anxiolytic and nootropic medication in Russia, where it has accumulated a defined safety profile through clinical use — a regulatory distinction that provides researchers with a translational framework not available for purely experimental compounds.

Mechanistically, Selank operates across overlapping neurological and immunological systems. Its primary anxiolytic mechanism involves modulation of GABA-A receptor function — increasing receptor sensitivity to GABA, producing anxiolytic and stress-relieving effects through the same receptor system targeted by benzodiazepines, but without sedation, tolerance development, or dependency risks. Independently, Selank upregulates BDNF and NGF expression, suggesting convergent anxiolytic and neurotrophic mechanisms.

The enkephalin system interaction adds another dimension: Selank stabilizes enkephalins against enzymatic degradation — extending the action of these endogenous opioid peptides and modulating their contribution to stress response regulation. Immunologically, tuftsin's parent activity (macrophage and NK cell activation) is partially preserved in Selank, creating bidirectional neuroimmune relevance for models studying stress-induced immune suppression.