Selank

Selank is a synthetic heptapeptide with the amino acid sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP). It was developed by the Institute of Molecular Genetics of the Russian Academy of Sciences as an analogue of tuftsin, a naturally occurring tetrapeptide (Thr-Lys-Pro-Arg) produced by enzymatic cleavage of the IgG immunoglobulin heavy chain. By appending the stabilizing tripeptide Pro-Gly-Pro to the native tuftsin sequence, researchers created a compound with substantially greater metabolic stability and prolonged biological activity. Selank has been studied and registered in Russia as a pharmaceutical treatment for generalized anxiety disorder (GAD) and neurasthenia under the brand name Selanc.

The mechanisms by which Selank produces its anxiolytic and nootropic effects involve multiple interconnected neurotransmitter systems. Primary among these is modulation of the GABAergic system: Selank upregulates GABA-A receptor sensitivity and influences the expression of genes involved in GABA synthesis, transport, and receptor subunit composition. The resulting anxiolytic effect is comparable in magnitude to low-dose benzodiazepines. Critically, this GABAergic activity does not produce the sedation, muscle relaxation, tolerance, physical dependence, or withdrawal phenomena associated with conventional benzodiazepine anxiolytics. Published head-to-head clinical trials comparing Selank to the benzodiazepine medazepam found equivalent anxiety reduction alongside additional antiasthenic effects (relief of fatigue and weakness) and mild psychostimulation with Selank, effects absent with the benzodiazepine.

Beyond GABA, Selank rapidly upregulates brain-derived neurotrophic factor (BDNF) expression in the hippocampus. BDNF is a key promoter of synaptic plasticity, neurogenesis, and long-term potentiation, making it a central target for cognitive enhancement research. Animal studies demonstrate that Selank-induced BDNF elevation occurs within hours of administration. Selank also modulates serotonin and dopamine neurotransmission, contributing to its reported effects on mood, motivation, and stress resilience. Gene expression studies have shown that Selank affects transcripts related to both GABAergic neurotransmission and immune signaling, reflecting the dual heritage of its parent compound tuftsin.

The evidence base for Selank is predominantly from Russian and CIS research institutions, creating gaps in the international peer-reviewed literature and limiting independent validation. However, the available controlled clinical data, combined with a well-characterized multi-target mechanism and a consistently favorable safety profile across both animal and human studies, has generated substantial interest from the research community, clinicians practicing integrative psychiatry, and individuals exploring nootropic and anxiolytic compounds. Long-term safety data beyond the durations studied in published trials (typically a few weeks) remain unavailable.