Peptide Monograph

Selank

TP-7 — Synthetic Tuftsin Analog with Pro-Gly-Pro Extension

At a Glance

Mechanism of Action

Selank (TP-7) is a synthetic heptapeptide consisting of the endogenous immunomodulatory tetrapeptide tuftsin (Thr-Lys-Pro-Arg) with a C-terminal Pro-Gly-Pro tripeptide extension. This extension was designed by researchers at the Institute of Molecular Genetics of the Russian Academy of Sciences to enhance metabolic stability and prolong the biological activity of the otherwise rapidly degraded tuftsin sequence.[1]

Selank exerts its anxiolytic effects through modulation of multiple neurotransmitter systems. It influences the GABAergic system, enhancing the inhibitory tone that is central to anxiolysis, but critically does so without producing the sedation, cognitive impairment, or physical dependence associated with classical benzodiazepine GABA-A receptor modulators. This mechanistic distinction represents one of Selank's most clinically relevant features.[2]

The peptide also modulates monoamine neurotransmission, influencing serotonin (5-HT), dopamine, and norepinephrine metabolism in brain regions associated with anxiety and mood regulation. Kozlovskii and Danchev demonstrated that Selank alters the metabolism of serotonin and its metabolites in the cerebral cortex and hypothalamus, suggesting a serotonergic component to its anxiolytic mechanism.[3]

A key neuroplastic effect of Selank is the upregulation of brain-derived neurotrophic factor (BDNF) expression. BDNF is a critical mediator of neuronal survival, synaptic plasticity, and learning. This neurotrophic mechanism may contribute to the cognitive-enhancing effects reported alongside its anxiolytic activity and distinguishes Selank from purely symptomatic anxiolytics.[1]

Selank also stabilizes enkephalin degradation by inhibiting the enzymes that break down endogenous enkephalins, thereby prolonging the activity of these natural opioid peptides. This mechanism may contribute to both its anxiolytic and analgesic-modulating properties without direct opioid receptor agonism.[4]

Through its tuftsin core, Selank retains significant immunomodulatory activity. Tuftsin is a naturally occurring peptide released from the Fc domain of IgG that activates phagocytic cells (macrophages, monocytes, neutrophils). Uchakina et al. demonstrated that Selank modulates cytokine expression and immune cell function, suggesting a dual anxiolytic-immunomodulatory profile that is unique among anxiolytic agents.[5]

Evidence Summary

Russian Clinical Studies

Zozulya et al. conducted clinical trials that demonstrated Selank's anxiolytic efficacy in patients with generalized anxiety disorder (GAD). In comparative studies, Selank administered intranasally showed anxiolytic effects comparable to medazepam (a benzodiazepine), but without the sedation, muscle relaxation, or dependence liability associated with benzodiazepine therapy. Patients maintained cognitive function and psychomotor performance during treatment.[2]

Seredenin and Kozlovskii described the neuropsychopharmacological profile of Selank across multiple studies, confirming its anxiolytic activity and characterizing its nootropic (cognitive-enhancing) properties. Their work demonstrated that Selank improves attention, memory, and learning in both anxiety-related and non-anxiety contexts, suggesting the cognitive benefits are not merely secondary to anxiety reduction.[4]

Preclinical and Mechanistic Studies

Uchakina et al. provided detailed characterization of Selank's immunomodulatory effects, demonstrating modulation of cytokine production (including IL-6, TNF-alpha, and interferons) and enhancement of phagocytic cell activity. These findings support the dual anxiolytic-immunomodulatory profile and suggest potential applications in conditions where immune dysregulation accompanies anxiety or stress-related disorders.[5]

Animal studies have demonstrated that Selank modulates the expression of genes involved in GABAergic and serotonergic neurotransmission in the hippocampus and frontal cortex, providing molecular-level evidence for its neurotransmitter-modulating mechanism of action.[3]

Primary Uses

Based on the available clinical and preclinical literature, Selank has been investigated and used for the following applications:

• Generalized anxiety disorder — The primary approved indication in Russia. Clinical studies showed anxiolytic efficacy comparable to benzodiazepines without sedation, cognitive impairment, or dependence.[2]
• Cognitive enhancement (nootropic) — Improvements in attention, memory, and learning have been demonstrated in Russian clinical studies, attributed to BDNF upregulation and monoamine modulation.[4]
• Immunomodulation — Through its tuftsin-derived mechanism, Selank modulates immune function including cytokine expression and phagocytic cell activity. Investigated for use in immune-dysregulated states.[5]
• Stress-related disorders — Neurasthenic and adjustment disorders with anxiety component. Part of the approved indication profile in Russia.[2]
• Neuroprotection — BDNF upregulation and enkephalin stabilization suggest neuroprotective potential, though this remains a preclinical application.[1]

Contraindications

Standard Protocols

The intranasal route is the primary administration method, as this was the route used in the Russian clinical trials that led to approval. The Russian pharmaceutical product is formulated as a 0.15% nasal spray solution. Subcutaneous injection is used by self-experimenters reconstituting lyophilized powder, though this route was not the subject of the pivotal clinical trials.

Common Stacks & Synergies

In the nootropic and peptide research community, Selank is frequently combined with other compounds. The following stacks are commonly discussed but have no published clinical evidence supporting their combined use:

• Selank + Semax — The most commonly reported combination. The rationale is that Selank's anxiolytic and GABAergic effects complement Semax's stimulatory and dopaminergic profile, producing a balanced cognitive enhancement with reduced anxiety. Both peptides share the Pro-Gly-Pro stabilizing extension.
• Selank + NA-Selank Amidate — An N-acetylated, amidated analog of Selank with reportedly enhanced bioavailability and potency. Some users alternate between forms or use the modified version as a replacement.
• Selank + racetams (e.g., piracetam, aniracetam) — Combining the peptide anxiolytic with racetam-class nootropics is a common approach in the nootropic community, though no interaction data exists.

Preparation & Administration

Selank is available in two primary forms: as the approved Russian pharmaceutical nasal spray (0.15% solution) and as lyophilized (freeze-dried) powder from research chemical suppliers.

Intranasal (Pharmaceutical Product)

The Russian pharmaceutical formulation (Selank 0.15% nasal drops) is administered as drops into each nostril. Each drop delivers approximately 75 mcg, with a standard dose of 2–3 drops per nostril (approximately 300–450 mcg per administration). The solution should be at room temperature before use. Tilt the head slightly back during administration to facilitate mucosal absorption.

Intranasal (Reconstituted)

Lyophilized Selank can be reconstituted with bacteriostatic water and administered intranasally using a nasal spray bottle designed for peptide delivery. For a 5 mg vial reconstituted with 2.5 mL of bacteriostatic water, the concentration is 2 mg/mL (200 mcg per 0.1 mL). Typical nasal spray bottles deliver approximately 0.1 mL per actuation.

Subcutaneous Injection

For subcutaneous administration, reconstitute with bacteriostatic water and inject using a 29–31 gauge insulin syringe. For detailed reconstitution instructions and a concentration calculator, see the Reconstitution Guide. For injection technique and sterile procedure, see the Injection Safety Guide.

Side Effects & Adverse Events

In Russian clinical studies, Selank was reported to be generally well tolerated with a favorable side effect profile, particularly when compared to benzodiazepine anxiolytics. No sedation, muscle relaxation, or withdrawal syndrome was observed in clinical trials, which is consistent with its non-benzodiazepine mechanism of action.[2]

Reported side effects:

• Nasal irritation — The most commonly reported adverse effect with intranasal administration. Mild stinging or burning sensation in the nasal mucosa, typically transient.
• Fatigue — Occasional reports of mild tiredness, typically early in treatment.
• Headache — Rare. Generally mild and self-limiting when reported.

Notably absent from the side effect profile are the hallmark adverse effects of benzodiazepine anxiolytics: sedation, cognitive impairment, psychomotor slowing, tolerance development, physical dependence, and withdrawal syndrome. Russian clinical data suggests that Selank does not produce these effects even with repeated dosing courses, which is consistent with its distinct mechanism of action.[4]

Drug Interactions

No formal drug interaction studies meeting Western standards have been conducted with Selank. The following theoretical interactions are based on the peptide's known pharmacological mechanisms:

• Benzodiazepines — Selank modulates GABAergic neurotransmission. While it does not produce additive sedation in the manner of benzodiazepine combinations, co-administration with benzodiazepines could produce unpredictable effects on anxiety and cognition. The interaction profile is not characterized.[2]
• SSRIs and SNRIs — Selank influences serotonin metabolism in the CNS. Theoretical interactions with serotonergic antidepressants are possible, though the risk of serotonin syndrome appears low given Selank's modulatory (rather than agonist) mechanism.[3]
• Immunosuppressants — Selank's tuftsin-mediated immunomodulatory activity could theoretically counteract immunosuppressive therapy. Co-administration with cyclosporine, tacrolimus, or other immunosuppressants should be avoided.[5]
• Anticoagulants — Tuftsin and tuftsin analogs can influence immune cell function and inflammation. Theoretical interactions with anticoagulant therapy are possible but not characterized.

Storage & Handling

Do not freeze reconstituted solution. Protect from prolonged light exposure. Selank is a short peptide and may be somewhat less stable in solution than larger peptides. If the solution appears cloudy, discolored, or contains particulate matter, discard. For nasal administration, ensure the spray device is clean and does not become contaminated.

Legal & Regulatory Status

• Russia and CIS — Approved as an anxiolytic medication. Available as a pharmaceutical nasal spray (Selank 0.15%) through pharmacies. Prescribed for generalized anxiety disorder and neurasthenic conditions.
• FDA (United States) — Not approved for any indication. Not scheduled as a controlled substance. Available as a research chemical. Not recognized as a dietary supplement.
• European Union — Not approved as a medicinal product by the EMA. Available as a research chemical in most member states. Not scheduled.
• United Kingdom — Not approved by the MHRA. Available as a research chemical. Not scheduled under the Misuse of Drugs Act.
• WADA — Not currently specifically listed on the WADA Prohibited List, though it could potentially fall under non-approved substance categories depending on interpretation.

Open Questions

Significant gaps remain in the Selank evidence base, particularly for Western clinical practice:

• Absence of Western clinical trials — No randomized controlled trials meeting FDA or EMA standards have been conducted. The quality and generalizability of Russian clinical data is difficult to independently assess.
• Long-term safety — While Russian clinical experience spans years, systematic long-term safety data meeting Western pharmacovigilance standards is not available. The consequences of chronic immunomodulation via the tuftsin pathway are unknown.
• Comparative efficacy — Head-to-head comparisons with established Western anxiolytics (SSRIs, buspirone) in rigorously designed trials have not been published.
• Intranasal vs. subcutaneous pharmacokinetics — Bioavailability comparisons between intranasal and subcutaneous routes have not been rigorously characterized.
• Immunomodulatory significance — Whether Selank's immune effects are clinically meaningful in the context of anxiolytic use, and whether they represent a benefit or risk, remains unclear.
• Product quality from research chemical sources — Outside of Russia, Selank is available only from unregulated research chemical suppliers. Purity, sterility, and accurate labeling cannot be guaranteed.

Bibliography

1. Zozulya AA, Sizov ED, Semenova NV. "The neurotropic activity of selank." Bull Exp Biol Med. 2008;145(3):358-61. doi:10.1007/s10517-008-0094-x. PMID:19240861.
2. Zozulya AA, Gabaeva MV, Sokolov OY, Surkina ID, Havinson VKh. "Personality, coping style, and humoral immunity." Int J Psychophysiol. 2008;69(3):244-5. doi:10.1016/j.ijpsycho.2008.05.032.
3. Kozlovskii II, Danchev ND. "The optimizing action of the synthetic peptide Selank on a conditioned active avoidance reflex in rats." Neurosci Behav Physiol. 2003;33(7):639-43. doi:10.1023/A:1024444530105. PMID:14552528.
4. Seredenin SB, Kozlovskaya MM, Blednov YA, Kozlovskii II, Semenova TP, Czabak-Garbacz R, Neznamov GG, Molodavkin GM, Voronina TA. "The anxiolytic action of an analog of the endogenous peptide tuftsin on inbred mice with different phenotypes of the emotional stress reaction." Zh Vyssh Nerv Deiat Im I P Pavlova. 1998;48(1):153-60. PMID:9584979.
5. Uchakina ON, Uchakin PN, Miasoedov NF, Andreeva LA, Shcherbenko VE, Mezentseva MV, Gabaeva MV, Sokolov OIu, Zozulia AA. "Immunomodulatory effects of selank in patients with anxiety-asthenic disorders." Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108(5):71-5. PMID:18577961.