Selank and semax are often discussed as a pair of intranasal peptides developed and registered in Russia, but they come from different parent molecules and are aimed at different effects: Selank at anxiety, Semax at cognition and neuroprotection. Neither is FDA-approved, and the evidence for both is largely Russian and preclinical.
Reviewed for accuracy · Last reviewed July 7, 2026The split is mostly by purpose. Selank derives from tuftsin and is registered in Russia as an anxiolytic, with its main human evidence a small comparative trial against a benzodiazepine. Semax derives from an ACTH fragment and is registered as a nootropic and neuroprotective agent, with evidence centered on neurotrophic effects in animal models of ischemia.
Both are given intranasally and both lack FDA or EMA approval, so in Western markets they are research compounds. The published evidence for each is thin by Western standards: small Russian human studies plus preclinical rat and cell work, rather than large placebo-controlled trials.
Choosing between them is really about the intended effect, anxiety versus cognition, but with the strong caveat that neither has well-established human efficacy outside its Russian registration. Product quality is an added, practical uncertainty because both are commonly sold as unregulated material.
This page is an independent educational reference and is not medical advice, and does not indicate any approval status for any use. Talk to a doctor before starting any compound.