A 7-amino-acid synthetic peptide based on the immunomodulatory peptide tuftsin (Thr-Lys-Pro-Arg) with an added Pro-Gly-Pro sequence for metabolic stability. Developed in Russia as an anxiolytic and nootropic. Approved in Russia for anxiety and neurasthenia.
Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is a synthetic heptapeptide developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It is based on tuftsin, a naturally occurring tetrapeptide (Thr-Lys-Pro-Arg) that is an immunomodulatory fragment of IgG.
The addition of Pro-Gly-Pro to tuftsin's C-terminus significantly increases metabolic stability (resistance to proteases) and adds CNS activity. Selank is approved in Russia as a nasal spray for treatment of generalized anxiety disorder and neurasthenia, and is widely used in the Russian nootropics community.
Selank's anxiolytic effect appears to work through multiple complementary pathways rather than a single receptor target. It enhances GABAergic transmission (without direct GABA-A binding), modulates enkephalin metabolism (affecting endogenous opioid tone), and increases BDNF expression — a neurotrophic factor critical for synaptic plasticity and memory.
| Pathway | Effect | Significance |
|---|---|---|
| GABA modulation | Enhances GABA-A receptor sensitivity to endogenous GABA | Anxiolytic effect without sedation or dependence |
| BDNF upregulation | Increases BDNF expression in hippocampus and cortex | Promotes synaptic plasticity, learning, and memory |
| Enkephalin metabolism | Inhibits enkephalin-degrading enzymes | Increases endogenous opioid tone (mild anxiolytic and analgesic) |
| Serotonin effects | Modulates serotonin turnover in hypothalamus | May contribute to mood-stabilizing effects |
| Immune modulation | Tuftsin-derived immunostimulatory effects | Enhances phagocyte activity and cytokine balance |
| Study | Design | Findings | Level |
|---|---|---|---|
| Generalized anxiety | Russian clinical trials | Significant reduction in anxiety scores (Hamilton Anxiety Scale) comparable to benzodiazepines but without sedation | Level II (Russian) |
| Cognitive enhancement | Clinical + preclinical | Improved memory and attention in anxiety patients; enhanced learning in animal models | Level II-III |
| BDNF increase | Preclinical + biomarker studies | Measurable increase in serum BDNF after 10-day intranasal course | Level II-III |
| Gene expression | Genomic studies | Selank modulates expression of 84 genes, including those involved in inflammation, apoptosis, and neuroplasticity | Preclinical |
Excellent safety profile: No significant adverse effects in Russian clinical trials. No sedation, no dependence, no withdrawal.
No abuse potential: Does not act as a direct GABA-A agonist (unlike benzodiazepines), so no addiction risk.
Limited Western data: Most clinical data is from Russian studies. Independent replication in Western trials is needed.
| Jurisdiction | Status |
|---|---|
| Russia | Approved as anxiolytic nasal spray (0.15% solution) |
| FDA | Not approved. Not reviewed. |
| International | Available as a research peptide in many countries |