Educational reference, not medical advice. This page summarizes information from published research and regulatory filings for educational purposes. It is not a recommendation to use any compound and should not replace guidance from a licensed healthcare provider. Most peptides discussed here are not approved for the uses described.
What it is
Selank is a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP). The first four residues are tuftsin — an endogenous immunomodulatory tetrapeptide originally identified as a fragment of the heavy chain of IgG. The C-terminal Pro-Gly-Pro extension is the same stabilizing motif used in Semax: it slows enzymatic degradation without altering the core pharmacology of the parent peptide.
The molecule is administered as an intranasal solution. Russian formulations are 0.15% nasal drops marketed under the trade name Selanc (also spelled Selank). The peptide is taken up through the nasal mucosa, with documented evidence of nose-to-brain transport in rodents.
History
Selank was developed in the 1990s in a collaboration between the Institute of Molecular Genetics and the Zakusov Research Institute of Pharmacology, both within the Russian Academy of Sciences. The development concept was to take advantage of the central effects associated with tuftsin while engineering enzymatic stability — the same Pro-Gly-Pro strategy used for Semax.
Early Russian-language preclinical work by Seredenin, Kozlovskaya, and colleagues described anxiolytic effects in rodent models of conflict behavior and elevated-plus-maze. Subsequent papers characterized effects on serotonin metabolism, BDNF expression, and inflammatory cytokine profiles. The peptide was approved by the Russian regulator in the mid-2000s for generalized anxiety disorder and adjustment disorders.
Regulatory status
Selank is approved in Russia for generalized anxiety disorder and adjustment-related neurasthenia, dispensed by prescription as Selanc nasal drops. It is not on the WHO Essential Medicines List and has not been approved by the FDA, EMA, MHRA, Health Canada, or the TGA.
Outside Russia and a small number of neighboring jurisdictions, Selank is sold by research-chemical suppliers under not-for-human-use labeling. There is no published Phase III trial in non-Russian populations.
How researchers describe its action
The published mechanism literature describes Selank as a multi-target neuromodulator with anxiolytic and immunomodulatory effects:
- GABAergic modulation. Several Russian-language papers report that Selank potentiates GABAergic signaling in rodent brain, which is the working hypothesis for the anxiolytic effect. Unlike benzodiazepines, Selank does not appear to act directly on the GABA-A receptor; the effect is described as indirect.
- Serotonin metabolism. Early Seredenin papers describe modulation of serotonin turnover in rat brain regions involved in anxiety.
- BDNF and immune signaling. Kolik and colleagues reported that Selank increases BDNF in hippocampus and prefrontal cortex in rats, and Kolomin and colleagues described changes in chemokine and cytokine gene expression after administration.
The receptor target of tuftsin itself is the neutrophil/macrophage receptor sometimes called Nrp1 or the tuftsin receptor; whether Selank acts through this receptor in the central nervous system is not definitively established.
Half-life and dosing intervals
Selank has a very short plasma half-life — published estimates place it in the range of 2 to 10 minutes after intranasal administration, with the heptapeptide hydrolyzed rapidly by serum aminopeptidases. As with Semax, the downstream behavioral and BDNF effects outlast the parent peptide.
Russian dosing labels for Selanc 0.15% specify two to three drops per nostril two to three times daily, delivering approximately 900 to 2,700 micrograms per day. Course durations of 14 days are common in the labeled use for generalized anxiety disorder, with longer courses possible at prescriber discretion.
Reconstitution example
Branded Selanc is supplied as a ready-to-use 0.15% nasal solution and does not require reconstitution. Research-grade Selank is sold as a lyophilized powder, typically in 5 mg or 10 mg vials. To approximate the commercial 1.5 mg/mL concentration, a 10 mg vial can be reconstituted with approximately 6.7 mL of bacteriostatic water or saline. One drop from a typical dropper (approximately 0.05 mL) then contains about 75 mcg.
What to know
- Limited Western data. The Selank literature is predominantly Russian-language and predominantly preclinical. No Phase III trial has been registered with the FDA or EMA.
- Intranasal only. Selank was designed for intranasal use; other routes have been explored in research but are not part of the approved formulation.
- Anxiolytic without sedation. Russian clinical data describe Selank as anxiolytic without the sedation, dependence, or withdrawal patterns associated with benzodiazepines, but long-term comparative safety data in non-Russian populations is unavailable.
- Reported adverse effects in the Russian labeling are limited to local nasal irritation. Systemic adverse effects are uncommon in the published data.
- Storage. The intranasal solution is refrigerated. Lyophilized Selank should be refrigerated or frozen; once reconstituted into solution, refrigerate and use within the stability window quoted by the supplier.
Sources
- 1.Kozlovskaya MM, Kozlovskii II, Val'dman EA, Seredenin SB (2003). Selank and short peptides of the tuftsin family in the regulation of adaptive behavior in stress. Neuroscience and Behavioral Physiology.
- 2.Kolik LG, Konstantinopolsky MA (2019). Selank, peptide analogue of tuftsin, protects against ethanol-induced memory impairment by regulating of BDNF content in the hippocampus and prefrontal cortex in rats. Bulletin of Experimental Biology and Medicine.
- 3.Kolomin TA, Shadrina MI, Andreeva LA, Slominsky PA, Limborska SA, Myasoedov NF (2011). Expression of chemokines and their receptors after Selank administration. Genetika.
- 4.Czabak-Garbacz R, Cygan B, Wolanski L, Kozlovsky I (2006). Influence of long-term treatment with tuftsin analogue TP-7 on the anxiety-phobic states and body weight. Pharmacological Reports.
- 5.Seredenin SB, Semenova TP, Kozlovskaia MM, et al. (1995). Anxiolytic action of the peptide Selank and its effect on serotonin metabolism in rat brain. Eksperimental'naya i Klinicheskaya Farmakologiya.