Selank: the Russian literature on this stabilized tuftsin analog
With no direct affinity for the GABA-A receptor but capable of potentiating GABAergic transmission: what the literature documents about Selank.
Selank is a synthetic heptapeptide derived from tuftsin (Thr-Lys-Pro-Arg), stabilized by the addition of the tripeptide Pro-Gly-Pro. Developed and initially studied in Russia, it is the subject of an abundant local pharmacological and clinical literature.
A stabilization that extends the half-life
Native tuftsin, an endogenous immunomodulatory peptide, is rapidly degraded by plasma peptidases. The addition of the C-terminal Pro-Gly-Pro tripeptide gives Selank increased resistance to enzymatic degradation, extending its window of action in the models studied.
BDNF modulation without direct affinity for GABA-A
A notable point in the literature (PMID 26228446, 21390649): Selank potentiates GABAergic transmission without direct affinity for the GABA-A receptor — unlike benzodiazepines, which bind directly to this receptor. The reported mechanism instead involves modulation of hippocampal BDNF and NGF expression, upstream of GABAergic signaling.
Reported effects on stress and neurotransmission
Published work describes a moderate reduction in cortisol under acute stress conditions, a modulation of serotonin and norepinephrine, as well as an increase in endogenous enkephalin in the preclinical models studied.
Anxiolytic without sedation: a pharmacological distinction
The Russian literature positions Selank as an anxiolytic studied for its profile without associated sedation — an important pharmacological distinction compared to classic anxiolytics with direct action on GABA-A, which typically induce dose-dependent sedation.
Reported immunomodulatory effects
Beyond the central nervous system, immunomodulatory effects (modulation of IL-6 and IFN-α) have been documented in preclinical models and Russian clinical studies — a likely legacy of its structural relationship with tuftsin, an immunomodulatory peptide of origin.
A Russian peptide alongside Semax
Selank is frequently studied alongside Semax, the other Russian-origin research peptide extensively documented for its modulation of BDNF — the two being often cited together in the comparative literature on non-hormonal neurotrophic peptides.