27 amino acids

ApprovedCognitive & Nootropic

Selank

Also known as: Selanc, TP-7, Thr-Lys-Pro-Arg-Pro-Gly-Pro, Tuftsin Analog

Molecular weight
751.88 Da
Formula
C33H57N11O9
CAS
129954-34-3
Routes
3

Selank is a synthetic heptapeptide anxiolytic developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It is based on the naturally occurring immunomodulatory peptide tuftsin (Thr-Lys-Pro-Arg) with an additional Pro-Gly-Pro sequence attached at the C-terminus. This extension dramatically enhances metabolic stability while adding nootropic and anxiolytic properties not present in native tuftsin. Approved in Russia as an anxiolytic and nootropic medication (nasal spray formulation, 0.15% solution), selank represents one of the few peptide-based anxiolytics with formal clinical approval in any jurisdiction. It exerts its effects without the sedation, cognitive impairment, or dependence associated with benzodiazepines — making it a fundamentally different class of anti-anxiety compound. Selank modulates the GABAergic, serotonergic, and dopaminergic neurotransmitter systems while simultaneously providing immunomodulatory benefits through its tuftsin core. This dual neurotropic-immunomodulatory profile is unique among anxiolytic compounds and has generated significant interest in Western neuropharmacology research.

For educational and research purposes only
Last updated:Check the research sources

Section 01

What it's used for

Approved for Anxiety in Russia

Approved in Russia for anxiety disorders. In a 62-person trial, it eased anxiety about as well as the benzodiazepine medazepam, but without its sedation, memory problems, or withdrawal symptoms. How fast it starts working was not reported.

Human
Clinical wording

Selank's primary approved indication in Russia is for anxiety disorders. A 62-patient randomized clinical trial found anxiolytic efficacy comparable to the benzodiazepine medazepam, without the sedation, cognitive impairment, or withdrawal syndrome associated with benzodiazepines. The trial did not report a specific onset-of-action timeframe, so no onset window can be stated.

Memory and Attention Research

Researchers observed improved learning, memory, and attention, linked to increased BDNF, a brain-growth protein. Memory-task scores rose in both healthy and cognitively impaired subjects, supporting its nootropic (cognition-boosting) use.

AnimalHumanLimited data
Clinical wording

Research demonstrates selank improves learning, memory consolidation, and attention through BDNF-mediated neuroplasticity. It enhances performance on memory tasks in both normal and cognitively impaired subjects, supporting its nootropic classification.

Immune System Research

Derived from tuftsin, an immune-system molecule, this peptide is studied for immune effects. Studies found better resistance to viral and bacterial infections, stronger natural killer (NK) cell activity, and normalized inflammatory markers.

HumanAnimalLimited data
Clinical wording

The tuftsin-derived immunomodulatory effects make selank useful for immune research. Studies show improved resistance to viral and bacterial infections, enhanced NK cell activity, and normalized cytokine profiles in immunocompromised subjects.

Tested for Neurasthenia

A clinical trial in people tested this peptide for neurasthenia (fatigue-like symptoms with anxiety), finding reduced fatigue and anxiety plus better emotional stability. No study has tested it for stress-related adjustment disorders alone.

Human
Clinical wording

A human clinical trial evaluated selank for neurasthenia (asthenic symptoms occurring alongside anxiety disorders), showing antiasthenic and anxiolytic benefits with improved emotional stability. No published study was found evaluating selank specifically for stress-related adjustment disorders as a separate indication.

Eases Withdrawal Signs in Rats

In rats, this peptide reduced anxiety-like behavior during simulated alcohol withdrawal and eased distress signs of morphine withdrawal. No human trial on withdrawal has been published, and no benzodiazepine-withdrawal study was found.

AnimalHuman
Clinical wording

Animal studies show selank reduces withdrawal-related anxiety-like behavior in rats modeling alcohol withdrawal and attenuates aversive signs of morphine withdrawal in rats. No human clinical trial of selank in withdrawal states has been published, and no study of selank in benzodiazepine withdrawal was found.

Nerve-Protection Signal in Rats

In a rat study, nasal doses raised BDNF (a brain-growth protein) in the hippocampus, a proposed way to protect nerve cells. No published study has shown that it actually reduces nerve damage in stroke-like or toxic-injury models.

Animal
Clinical wording

An animal study shows that intranasal selank upregulates BDNF expression in the rat hippocampus, a mechanism proposed to support neuroprotection. No published study was found demonstrating that selank reduces neuronal damage in ischemic or excitotoxic injury models.

Section 02

Mechanism of Action

Mechanism 01

Calming signals without the sedation

  • Selank makes the brain's main calming receptor more sensitive and raises levels of the calming messenger GABA.
  • It does this by blocking the enzyme that normally breaks that messenger down.
  • Unlike benzodiazepines, which act on the receptor directly, this indirect route is described as non-sedating.
  • Reported effects include anxiety reduction without motor impairment or tolerance building up.
Clinical wording

GABAergic Modulation

Selank enhances GABA-A receptor sensitivity and increases GABA concentration in the synaptic cleft by inhibiting GABA-transaminase (the primary GABA-degrading enzyme). Unlike benzodiazepines, which directly potentiate GABA-A receptor activity, selank's indirect enhancement of GABAergic tone produces anxiolysis without sedation, motor impairment, or tolerance development.

Mechanism 02

Steadying the mood chemical system

  • Selank alters how the mood chemical serotonin is produced and cleared from nerve junctions.
  • It affects the enzyme that builds serotonin and the transporter that reabsorbs it.
  • Signalling is reported as more stable in the frontal cortex and the memory hub (hippocampus).
  • Studies report it normalises serotonin markers that are disturbed in anxiety states.
Clinical wording

Serotonergic System Regulation

Selank modulates serotonin (5-HT) metabolism by influencing tryptophan hydroxylase activity and serotonin transporter (SERT) function. It stabilizes serotonergic signaling in prefrontal cortex and hippocampus, contributing to mood regulation and anxiolytic effects. Studies show selank normalizes serotonin metabolism markers that are disrupted in anxiety states.

Mechanism 03

Boosting the brain's growth protein

  • Selank strongly increases a nerve growth protein (BDNF) in the memory hub and cortex.
  • That protein supports new connections between neurons, learning and mood regulation.
  • Its levels are characteristically reduced in anxiety and depression, which restoring them is meant to address.
Clinical wording

BDNF and Neurotrophin Expression

Selank significantly upregulates brain-derived neurotrophic factor (BDNF) expression in hippocampus and cortex — a key mediator of neuroplasticity, learning, and mood regulation. BDNF levels are characteristically reduced in anxiety and depression, and selank's ability to restore BDNF expression contributes to both anxiolytic and nootropic effects.

Mechanism 04

Prolonging the body's own opioids

  • Selank blocks the enzymes that destroy enkephalins, the body's own mood-lifting opioid-like peptides.
  • Making those signals last longer indirectly increases activity at two opioid receptor types.
  • It does this without binding opioid receptors itself, and is linked to stress resilience.
Clinical wording

Enkephalin System Modulation

Selank inhibits enzymes that degrade enkephalins (endogenous opioid peptides with anxiolytic and mood-elevating properties). By prolonging enkephalin signaling, selank indirectly enhances μ and δ opioid receptor activity, contributing to stress resilience and anxiolysis without direct opioid receptor binding.

Mechanism 05

An immune fragment inside the molecule

  • Selank is built around a four-amino-acid immune fragment (tuftsin) that activates several immune cell types.
  • It shifts immune messengers, raising an anti-inflammatory one and lowering two inflammatory ones.
  • Authors suggest this may add to the calming action, since brain inflammation is increasingly tied to anxiety.
Clinical wording

Immunomodulation via Tuftsin Core

The tuftsin (Thr-Lys-Pro-Arg) core sequence activates NK cells, macrophages, and T-cells. It modulates cytokine production — enhancing IL-10 (anti-inflammatory) while reducing TNF-α and IL-6 (pro-inflammatory). This immunomodulatory effect may contribute to the anxiolytic action, as neuroinflammation is increasingly recognized as a contributor to anxiety.

Section 03

Biological Pathways

  1. GABA-A/Chloride Channel EnhancementSelank increases synaptic GABA availability and GABA-A receptor coupling, promoting chloride influx and neuronal hyperpolarization, reducing excitatory transmission in the amygdala and prefrontal cortex.
  2. BDNF/TrkB/MAPK Neuroplasticity PathwayBDNF upregulation activates TrkB receptor signaling, engaging the Ras/MAPK/ERK cascade to promote dendritic spine formation, synaptic strengthening, and neuronal survival in hippocampus and cortex.
  3. IL-6/STAT3 Immune RegulationSelank modulates the IL-6/STAT3 inflammatory pathway, reducing neuroinflammation linked to anxiety and cognitive impairment, while enhancing innate immune surveillance via NK cell and macrophage activation.
  4. Dopamine/D2 Reward PathwaySelank normalizes dopaminergic signaling in mesolimbic and mesocortical pathways, improving motivation and hedonic tone without the euphoria or dependence linked to direct dopamine agonists.

Section 04

Dosage Information

Amino acid sequence
Thr-Lys-Pro-Arg-Pro-Gly-Pro
Ranges reported in experimental work
Route / systemContextRange studiedLimitation
Intranasal — 0.15% dropsRussian label, anxiety disorders and neurastheniaOne drop = 0.05 mL = 75 µg. Single 300–900 µg (4–12 drops), daily 900–2,700 µg (12–36 drops) — usually 2 drops per nostril 3×/day.Written for diagnosed anxiety disorder or neurasthenia, 10–14 days then stop. No dose was ever set for continuous use or ordinary stress.
Intranasal — anxiety trialRandomised trial vs medazepam in anxiety and neurasthenia62 patients, 14 days — 30 on selank, 32 on medazepam. No dose in PubMed; summaries say 1,350 µg/day, inside the label's 900–2,700 µg.Registration rests on 30 treated patients, compared with another drug rather than a dummy, published in Russian and never repeated outside Russia.
Intranasal / subcutaneousSelf-administration; sprays and research vialsSprays are labelled 100–150 µg per spray; 600–2,700 µg a day in 2–3 doses circulates. Injected use circulates at 250–500 µg a day.Nasal figures restate the label through a pump that gives no 0.05 mL drop. The injected ones rest on nothing: Selank was registered and tested only as drops.
Dosage calculatorMass · concentration · volume · U-100

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Research Use Only. This information is for educational and research purposes only. Not intended for medical advice or self-medication.

Section 05

Protocols

  1. Protocol 01

    Semax + Selank Cognitive Stack

    Nootropic peptide stack for focus, memory, anxiety reduction, and neuroprotection.

    Focus
    Cognitive
    Level
    Beginner
    Duration
    4–8 weeks
    View Full Protocol

Section 06

Stability & Storage

  1. Lyophilised powder

    Selank ships as lyophilised powder for research use, kept at −20°C for long-term stability (18-24 months) or at 2-8°C for up to 6 months. A commercial 0.15% nasal spray solution (sold in Russia) is stored at 2-8°C, protected from light, with a 2-year shelf life.

  2. After reconstitution

    Reconstituted with bacteriostatic water, the solution is kept at 2-8°C and used within 21 days. Intranasal delivery reaches the CNS directly through the olfactory epithelium and avoids first-pass liver metabolism; subcutaneous injection is used as an alternative research route.

Section 07

Side Effects & Precautions

Clinical trials and post-marketing surveillance in Russia found no serious adverse effects attributed to Selank at approved doses.

  1. No sedation

    Unlike benzodiazepines, Selank does not cause drowsiness, motor impairment, or cognitive dulling at therapeutic doses.

  2. No tolerance or dependence

    Selank does not produce tolerance with chronic use and has no documented withdrawal syndrome, unlike benzodiazepines.

  3. No significant drug interactions

    No clinically significant drug interactions have been reported; Selank can be used alongside most medications without dose adjustments.

  4. Local and mild effects

    • Mild burning or tingling sensation in nasal passages may occur with intranasal administration, typically lasting less than 1 minute.
    • Occasional mild headache has been reported during initial use, typically resolving spontaneously.

Section 08

Regulatory Status

Selank is an approved prescription-free medicine in Russia and an unapproved research peptide everywhere else.

No Western drug regulator has reviewed it, and it is not restricted in competitive sport.

  1. Russia

    Approved anxiolytic and nootropic medicine

    First registered on 30 April 2009 under ЛСР-003338/09, the 0.15% nasal drops now hold ЛП-№(010951)-(РГ-RU), issued 15 July 2025 once the dossier was aligned with EAEU rules; they have been sold over the counter since 2 August 2017.

  2. FDA / United States

    Not approved, classified as research

    Selank has no FDA approval and no established prescribing information in the United States; it is distributed as a research peptide rather than a licensed drug.

  3. European Union

    Not approved either

    No EU member state or the EMA has authorised Selank as a medicine, and Russia is the only country where it is licensed at all — the registers of Belarus, Kazakhstan and Ukraine hold no entry for it.

  4. WADA

    Not on the prohibited list

    Selank does not appear on the WADA Prohibited List and carries no documented performance-enhancing effect or dependence risk in the published clinical literature.

A national registration is not an international one — approval in Russia does not carry over to the FDA, the EMA or any other regulator. Regulatory status differs by jurisdiction and changes over time; check the current documents of your own regulator before relying on any of this.

Section 09

Research Studies

  1. [1]Selank Administration Affects the Expression of Some Genes Involved in GABAergic NeurotransmissionVolkova A, Shadrina M, Kolomin T, et al. · Frontiers in Pharmacology · 2016
  2. [2]GABA, Selank, and Olanzapine Affect the Expression of Genes Involved in GABAergic Neurotransmission in IMR-32 CellsFilatova E, Kasian A, Kolomin T, et al. · Frontiers in Pharmacology · 2017
  3. [3]Comparison of the effects of selank and tuftsin on the metabolism of serotonin in the brain of rats pretreated with PCPASemenova TP, Kozlovskii II, Zakharova NM, Kozlovskaya MM. · Eksperimentalnaia i Klinicheskaia Farmakologiia · 2009
  4. [4]Intranasal administration of the peptide Selank regulates BDNF expression in the rat hippocampus in vivoInozemtseva LS, Karpenko EA, Dolotov OV, et al. · Doklady Biological Sciences · 2008
  5. [5]Selank, Peptide Analogue of Tuftsin, Protects Against Ethanol-Induced Memory Impairment by Regulating of BDNF Content in the Hippocampus and Prefrontal Cortex in RatsKolik LG, Nadorova AV, Antipova TA, et al. · Bulletin of Experimental Biology and Medicine · 2019
  6. [6]The Inhibitory Effect of Selank on Enkephalin-Degrading Enzymes as a Possible Mechanism of Its Anxiolytic ActivityZozulya AA, Kost NV, Sokolov OYu, et al. · Bulletin of Experimental Biology and Medicine · 2001
  7. [7]Semax and Selank Inhibit the Enkephalin-Degrading Enzymes of Human SerumKost NV, Sokolov OYu, Gabaeva MV, et al. · Russian Journal of Bioorganic Chemistry · 2001
  8. [8]Expression of inflammation-related genes in mouse spleen under tuftsin analog SelankKolomin T, Shadrina M, Andreeva L, et al. · Regulatory Peptides · 2011
  9. [9]The temporary dynamics of inflammation-related genes expression under tuftsin analog Selank actionKolomin T, Morozova M, Volkova A, et al. · Molecular Immunology · 2014
  10. [10]Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurastheniaZozulya AA, Neznamov GG, Siuniakov TS, et al. · Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova · 2008

Section 10

Frequently Asked Questions

In a 62-patient randomised trial comparing selank against the benzodiazepine medazepam over 14 days, selank produced anxiolytic effects reported as comparable to medazepam, without the sedation, cognitive impairment or withdrawal syndrome seen with benzodiazepines. That is the entire published human efficacy record — one trial, run in Russia, never repeated outside it, and the trial did not report a specific onset-of-action timeframe.

The 14-day anxiolytic trial did not report how quickly effects appeared, only that they were present by the end of the study. The Russian label is written for a 10-to-14-day course for a diagnosed anxiety disorder or neurasthenia; no dose or duration was ever established for continuous use or everyday stress.

Selank is approved only in the Russian Federation (marketing authorisation ЛП-№(010951)-(РГ-RU), issued 15 July 2025; first registered in 2009 as ЛСР-003338/09) as an over-the-counter 0.15% nasal spray for anxiety and neurasthenia. It has no approval from the FDA, EMA or any Western regulator, and Russia is the only country where it is registered at all — the registers of Belarus, Kazakhstan and Ukraine hold no entry for it. It is not on the WADA prohibited list and carries no documented abuse potential.

The Russian label is built around a 0.05 mL, 75 µg drop: single doses of 300–900 µg and daily totals of 900–2,700 µg, usually 2 drops per nostril three times a day. Injected doses of 250–500 µg circulating online rest on nothing — selank was registered and tested only as nasal drops, never as an injectable.

No significant drug interactions have been reported in selank's trial and post-marketing record, and it is described as usable alongside most medications without dose adjustment. But that is a general safety observation, not a dedicated study — no trial has specifically tested selank combined with an SSRI, Wellbutrin or a benzodiazepine like Xanax.

The documented profile is unusually clean: mild, brief nasal burning or tingling, occasional mild headache, and no sedation, motor impairment or cognitive dulling at labelled doses. No tolerance or withdrawal syndrome has been observed with chronic use, which is the main safety contrast drawn against benzodiazepines.

The lyophilised research powder is stable at −20°C for 18–24 months or at 2–8°C for up to 6 months. The commercial 0.15% nasal spray sold in Russia is kept at 2–8°C, protected from light, with a 2-year shelf life; once reconstituted from powder, a solution is kept at 2–8°C and used within 21 days.