Selank

Developed at the Institute of Molecular Genetics, Russian Academy of Sciences, and made by Peptogen. It is tuftsin, a small immune-system peptide, with a Pro-Gly-Pro tail added for stability (the same tail used in Semax). Russia registered it in 2009 as nasal drops and made it non-prescription in 2017.

Not established in humans. Proposed pathways, mostly from rats, include modulation of the GABA system, inhibition of enzymes that break down the body's own enkephalins, changes in serotonin and other monoamines, a rise in hippocampal BDNF, and immune cytokine modulation; antiviral activity has been seen in cell and animal models.

Russian clinical studies in generalized anxiety and neurasthenia, including comparisons with a benzodiazepine, are cited, but their designs could not be independently checked. A 2025 Russian study after kidney surgery reported better recovery but gave little detail. Rat studies report changes in GABA-pathway genes, reduced oxidative stress after brain injury, prevention of alcohol-induced memory deficits and reversal of stress-induced gut microbiota changes. Claims of no dependence or withdrawal trace back to the developer's own work; formal half-life, safety by non-nasal routes and long-term safety are unstudied.

The Russian label lists allergic reactions (including delayed), unpleasant taste and possible preservative allergy, with no frequencies; no overdose cases have been reported. FDA lists immunogenicity risk from aggregation and impurities and says key safety information is lacking. The Russian label rules it out in pregnancy, breastfeeding and under age 18; long-term safety and safety by non-nasal routes are unknown.

Not FDA-approved for any use; its compounding nomination was withdrawn and it had no FDA advisory review, so it is not compoundable. Approved in Russia as nasal drops (non-prescription since 2017). Not named on the 2026 WADA list, and because it is approved in Russia, S0 arguably does not apply.