Selank

Selank is a synthetic tuftsin analog (Thr-Lys-Pro-Arg-Pro-Gly-Pro) marketed in Russia as a 0.15% intranasal drop. It functions as an anxiolytic neuropeptide without a single universally accepted receptor mechanism. It is not FDA or EMA approved.

Selank does not have a single, classically defined receptor mechanism. Evidence points to a network effect: primary studies report inhibition of enkephalin-degrading enzymes, transcriptomic work shows changes in genes involved in neurotransmission (including GABA-system-related genes), and human immunology work suggests cytokine-regulating effects. The cleanest rigorous summary is that Selank modulates neurochemical and possibly immunologic signaling rather than acting as a classic direct benzodiazepine-receptor agonist. Russian PK data: absolute intranasal bioavailability 92.8%, detected in plasma within 30 seconds, plasma concentration declines over 5–5.5 minutes.