COMPOUND

Compounds / Cognitive

Selank

Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro), synthetic tuftsin analog

Cognitive Nasal · SubQ Approved outside the US

Synthetic heptapeptide developed at the Russian Academy of Sciences Institute of Molecular Genetics under N.F. Myasoedov (1990s). Built by extending endogenous tuftsin (Thr-Lys-Pro-Arg) with Pro-Gly-Pro to improve metabolic stability. Approved in Russia as a 0.15% intranasal solution for generalized anxiety disorder and neurasthenia. Used by biohackers as a non-sedating anxiolytic alternative to benzodiazepines: for anxiety, social inhibition, post-stim agitation, post-cycle.

At a glance

Half-life
~3 min Plasma t½ ~2-3 minutes: much longer than parent tuftsin (~20-30 sec) due to Pro-Gly-Pro stabilization. Behavioral effect persists 12-24h via active metabolite fragments. Intranasal bioavailability ~93% in rodent radiolabel studies: high for a peptide via direct nose-to-brain transport (olfactory + trigeminal pathways).
Routes
Nasal · SubQ
Vial sizes
3 mg · 5 mg · 10 mg
Evidence base
4 studies 2 human · 2 preclinical

Mechanism

Modulates GABAergic tone: quantitative gene-expression data show 45 GABA-system genes shift in rat frontal cortex within 1h of intranasal Selank, with strong correlation (r=0.86) to GABA's own effects. Acts allosterically: does not bind benzodiazepine sites, no tolerance / withdrawal. Additionally inhibits enkephalin-degrading enzyme (raising endogenous enkephalin tone: anxiolytic + analgesic), modulates BDNF and serotonergic signaling, and may engage immune-modulatory pathways via parent tuftsin's macrophage-activating activity. Anxiolytic efficacy comparable to benzodiazepine medazepam; benefit persists ~1 week post-treatment.

Dosing

Any amounts shown here are reported from published studies only. 2 of 4 catalogued studies involved human subjects. COMPOUND does not publish its own dosing guidance.

Published evidence

  1. Human observational 2014

    A comparison of the anxiolytic effect and tolerability of selank and phenazepam in the treatment of anxiety disorders

    Medvedev VE, Tereshchenko ON, Israelian AIu, et al. Zh Nevrol Psikhiatr Im S S Korsakova

    n=60 phobic-anxiety / somatoform patients. Anxiolytic + mild nootropic effects; benefit persisted ~1 week post-treatment; better tolerability than phenazepam.

    PMID 25176261

  2. Human observational 2008

    Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia

    Zozulia AA, Neznamov GG, Siuniakov TS, et al. Zh Nevrol Psikhiatr Im S S Korsakova

    n=62 (30 Selank vs 32 medazepam). Anxiolytic efficacy comparable to benzodiazepine medazepam, with additional antiasthenic and psychostimulant effects. Decreased serum enkephalin activity correlated with symptom severity and improved with Selank: supports enkephalinase inhibition mechanism.

    PMID 18454096

  3. Animal in vivo 2016

    Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission

    Volkova A, Shadrina M, Kolomin T, et al. Front Pharmacol

    Mechanistic study: intranasal Selank 300 µg/kg in rats altered 45 GABA-system genes within 1h. Strong correlation (r=0.86) with direct GABA effects, suggesting allosteric rather than orthosteric GABA-site action.

    PMID 26924987

  4. Animal in vivo 2003

    Selank and short peptides of the tuftsin family in the regulation of adaptive behavior in stress

    Kozlovskaya MM, Kozlovskii II, Val'dman EA, Seredenin SB Neurosci Behav Physiol

    Foundational pre-clinical animal-behavior work. Established Selank's anxiolytic + anti-stress effects in elevated plus maze, open field, stress-resistance models.

    PMID 14969422

Reported side effects

Generally well-tolerated
Very common Mild · Russian clinical literature consistently describes Selank as well-tolerated. No sedation, no cognitive impairment, no motor coordination deficit, no dependence/withdrawal. Key differentiator vs benzodiazepines.
Mild nasal irritation
Occasional Mild · Usually attributed to formulation vehicle (saline, preservatives) rather than the peptide.
Headache
Rare Mild · Infrequent, self-limiting.
Limited long-term safety data outside Russia
Unknown Mild · Russian clinical use spans ~15 years with apparent good safety; multi-year prospective data and post-marketing surveillance outside Russia are sparse.

Interactions

  • Semax Synergy

    Most-cited Russian-peptide stack: Selank (anxiolytic via GABA / enkephalin) + Semax (cognitive via BDNF/TrkB). 'Calm + sharp' community combination.

  • Benzodiazepines Caution

    Selank acts on GABAergic system allosterically; additive sedation / cognitive effect possible with benzodiazepine co-administration. Zozulia 2008 found Selank reduced benzo dose requirements when added to standard therapy.

Reconstitution and storage

Most users buy pre-formulated 0.15% intranasal spray (3 mL bottle = 4.5 mg total Selank, ~150 mcg per spray). Custom prep from lyophilized: 5 mg vial + 3.3 mL sterile saline = 0.15% solution. For SC: 5 mg + 2 mL BAC water = 2.5 mg/mL = 250 mcg per 0.1 mL.

Pre-formulated nasal spray: refrigerate 2-8°C, use within 30 days. Lyophilized powder: freezer (-20°C) until reconstitution.

Open the reconstitution calculator for Selank