Report ID: Selank-2025-Q4-V1 Date: December 18, 2025 Disclaimer: This document is intended for informational and educational purposes only. It is not medical advice. The substance discussed is an investigational chemical not approved by the FDA for human use. Consult with a qualified healthcare professional for any medical concerns.
Executive Summary
Selank is a synthetic heptapeptide derivative of the human peptide Tuftsin, developed for its anxiolytic and nootropic properties. It acts as a stable regulatory peptide that modulates the expression of Brain-Derived Neurotrophic Factor (BDNF) and balances the degradation of enkephalins. Clinically used in Russia for Generalized Anxiety Disorder (GAD), it offers a unique non-sedating effect, improving mood, focus, and cognitive function while reducing stress and anxiety.
History and Discovery
Selank is a synthetic heptapeptide with pronounced anxiolytic (anti-anxiety) and nootropic (cognitive-enhancing) properties. Its development is a direct result of Russian military and academic research into immunopeptides.
- Origins and Key Researchers: Selank was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences in the late 1980s and early 1990s. The research was led by Academician Nikolai Myasoedov and his team, in collaboration with the V.V. Zakusov Research Institute of Pharmacology. The peptide was designed as a stable, synthetic analogue of the endogenous immunomodulatory peptide Tuftsin. Tuftsin (Thr-Lys-Pro-Arg) is a tetrapeptide known to stimulate phagocytic activity in immune cells. Researchers extended the Tuftsin sequence with a Pro-Gly-Pro fragment, creating Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) to enhance its stability and modify its biological activity, particularly its effects on the central nervous system (CNS).
- Timeline of Development:
- Late 1980s: Initial synthesis and preclinical investigation into the neuropsychotropic and immunomodulatory effects of Tuftsin analogues.
- 1990s: Extensive preclinical studies in Russia demonstrated Selank’s anxiolytic effects without the sedative or addictive properties of traditional benzodiazepines. Its mechanisms of action, including effects on the GABAergic system and enkephalin metabolism, were elucidated.
- Early 2000s: Human clinical trials commenced in Russia. Phase I and II trials confirmed its safety and tolerability.
- 2008-2009: Selank was approved and registered for clinical use in the Russian Federation and Ukraine for the treatment of Generalized Anxiety Disorder (GAD) and neurasthenia. It is typically marketed as a 0.15% intranasal spray.
- 2010-2020: Interest in Selank grew in Western biohacking and nootropic communities. Online forums, particularly Reddit, and podcasts popularized its use for anxiety, cognitive enhancement, and stress resilience. Its availability as a “research chemical” from online vendors fueled this trend.
- 2021-2025: Following the global focus on post-viral syndromes, academic interest in Selank’s dual neurotropic and immunomodulatory properties has seen a modest resurgence. Small-scale, non-commercial studies began exploring its potential for mitigating post-viral cognitive dysfunction (“brain fog”) and neuroinflammation. Search volume and community discussions have remained stable, indicating a persistent niche interest. No major Western clinical trials have been initiated as of late 2025, primarily due to patent expiration and the high cost of navigating the FDA/EMA regulatory process.
Chemical Structure and Properties
Selank’s unique chemical structure is key to its stability and biological function.
- Amino Acid Sequence: Threonyl-Lysyl-Prolyl-Arginyl-Prolyl-Glycyl-Proline
- One-Letter Code: TKPRPGP
- Molecular Formula: C₃₃H₅₇N₁₁O₉
- Molar Mass: 751.88 g/mol
- Modifications: Selank is a straightforward peptide chain without acetylation or amidation. The key structural modification is the Pro-Gly-Pro C-terminal extension added to the Tuftsin sequence. This fragment significantly increases the peptide’s resistance to degradation by peptidases in the blood and nasal mucosa, prolonging its biological activity compared to its parent compound.
- Pharmacokinetics:
- Administration Routes: Primarily administered as an intranasal spray. This route allows for rapid absorption through the nasal mucosa, partially bypassing the blood-brain barrier (BBB) for more direct CNS effects. It also undergoes systemic absorption. Subcutaneous (SubQ) injection is a secondary route, though less studied for its CNS effects. Oral administration is ineffective due to rapid enzymatic degradation in the gastrointestinal tract.
- Bioavailability: Intranasal bioavailability is estimated to be high for CNS targets, though precise figures are not well-established in Western literature. Systemic bioavailability is lower.
- Half-Life: The plasma half-life of Selank is very short, on the order of 1-2 minutes. However, its physiological and neurological effects are far more durable, lasting for hours to days. This discrepancy suggests a “hit-and-run” mechanism where the peptide rapidly binds to its targets, initiating downstream signaling cascades (e.g., gene expression changes for neurotrophins) that persist long after the peptide itself is cleared.
- Metabolism: Selank is rapidly broken down into smaller peptides and individual amino acids by plasma and tissue peptidases.
Mechanisms of Action
Selank exerts its effects through multiple, interconnected pathways, distinguishing it from conventional anxiolytics. Its mechanism is primarily modulatory rather than agonistic or antagonistic.
- Primary Pathways:
- GABAergic System Modulation: Selank does not bind directly to benzodiazepine receptors. Instead, it acts as an allosteric modulator of GABA-A receptors, potentiating the inhibitory effects of GABA. This enhances neuronal inhibition in a more balanced and subtle way than benzodiazepines, reducing anxiety without causing sedation, ataxia, or cognitive impairment.
- Enkephalin Degradation Inhibition: Selank inhibits the activity of enzymes (enkephalinases) that break down endogenous enkephalins. Enkephalins are natural opioid peptides involved in pain regulation, stress response, and mood. By increasing their concentration in the brain, Selank contributes to its anxiolytic and mild mood-elevating effects.
- Neurotrophin Expression Upregulation: Studies have shown that Selank administration leads to a rapid and significant increase in the mRNA expression of Brain-Derived Neurotrophic Factor (BDNF) in the hippocampus and other brain regions. BDNF is crucial for neurogenesis, synaptic plasticity, and long-term memory. This mechanism is central to Selank’s nootropic and potential antidepressant effects. It may also influence Nerve Growth Factor (NGF) levels.
- Secondary and Synergistic Pathways:
- Immunomodulation (Cytokine Regulation): As a Tuftsin analogue, Selank retains immunomodulatory properties. During periods of stress, it has been shown to modulate the expression of pro-inflammatory cytokines, particularly Interleukin-6 (IL-6). By balancing the immune response under stress, it may prevent stress-induced immunosuppression and neuroinflammation. This links its anxiolytic and immune-stabilizing functions.
- Monoamine System Interaction: Selank influences the metabolism of serotonin and norepinephrine, particularly in brain regions associated with emotion and cognition. It appears to stabilize their turnover rates, which may contribute to its antidepressant and anti-anhedonic properties, especially in stress-induced models.
Key Research Benefits
Based on preclinical and Russian clinical data, Selank is associated with the following key benefits:
- Potent Anxiolytic Effects: Reduces anxiety, worry, and restlessness without sedation or cognitive dulling, making it highly functional for daily use.
- Stress Resilience and Adaptation: Helps the body and mind adapt to and recover from acute and chronic stressors, both psychological and physiological.
- Cognitive Enhancement (Nootropic): Improves memory formation, learning capacity, and mental clarity, particularly under conditions of stress or fatigue. This is strongly linked to its BDNF-elevating mechanism.
- Mood Stabilization and Anti-Anhedonia: Can elevate mood and restore the ability to feel pleasure in individuals suffering from stress-induced anhedonia or mild depression.
- Neuroprotective Properties: Protects neurons from damage caused by hypoxia, excitotoxicity, and other insults, suggesting potential applications in recovery from brain injuries.
- Favorable Safety Profile: Lacks the significant side effects of traditional anxiolytics, such as physical dependence, withdrawal syndrome, amnesia, and motor impairment.
- Immunomodulatory Action: Balances the immune system, particularly under stress, and has demonstrated antiviral properties (against influenza virus in vitro/vivo) by modulating interferon production.
- Reduction of Asthenia: Combats mental and physical fatigue, particularly that associated with chronic anxiety or post-illness recovery.
- Accelerated Recovery from Neurological Insults: Preclinical models show it may aid in recovery from conditions like stroke or nerve damage by reducing neuroinflammation and promoting neurogenesis.
- Synergy with other Therapies: Can be used alongside other treatments for anxiety and depression to potentially enhance their efficacy or reduce their side effects.
Use Cases
Selank’s unique profile allows for a diverse range of applications, both clinically (in Russia/Ukraine) and experimentally.
- Generalized Anxiety Disorder (GAD): Its primary approved indication. Used to manage chronic worry, tension, and fear.
- Adjustment Disorder: Helps individuals cope with significant life stressors (e.g., job loss, bereavement).
- High-Stress Professions: Utilized by professionals (e.g., executives, first responders) to maintain cognitive performance and emotional stability under pressure.
- Academic and Exam Preparation: Students use it to enhance learning, improve memory consolidation, and reduce exam-related anxiety.
- Post-Viral Cognitive Dysfunction: Investigational use for clearing “brain fog,” improving focus, and reducing fatigue following viral illnesses.
- Phobia and Panic Attack Management: As an adjunct, it can help reduce the baseline anxiety that contributes to phobic responses and panic.
- Withdrawal from Benzodiazepines or Alcohol: Its non-addictive nature and GABAergic modulation may help mitigate withdrawal symptoms and cravings (preclinical evidence).
- Immune Support during Stressful Periods: Taken prophylactically during periods of high stress (e.g., travel, intense work projects) to prevent stress-induced illness.
- Enhancing Psychotherapy: By reducing anxiety, it can make patients more receptive to cognitive-behavioral therapy (CBT) and other therapeutic modalities.
- Mild Traumatic Brain Injury (TBI) Recovery: Experimental use to reduce neuroinflammation and promote neural repair via BDNF upregulation following concussion.
- Focus and Productivity Enhancement: Used by individuals in the biohacking community to achieve a calm, focused mental state conducive to deep work.
Clinical Research Data
This table summarizes key research, from foundational preclinical work to human trials and recent reviews.
| Study Type | Key Examples / Citations (Author, Year) | Key Findings |
|---|---|---|
| Human Clinical Trials | Zozulya, A.A., et al. (2001, 2008) | Efficacy and safety of Selank in treating GAD and neurasthenia are comparable to medazepam (a benzodiazepine) but with a significantly better side effect profile (no sedation or cognitive impairment). |
| Volkova, A.V., et al. (2016) | Investigated Selank’s effect on cognitive functions in patients with anxiety disorders, showing improvements in attention and memory. | |
| Preclinical (Anxiety) | Semenova, T.P., et al. (2010) | Demonstrated Selank’s anxiolytic effects in rodent models of anxiety (elevated plus-maze, open field tests). |
| Kozlovskaya, M.M., et al. (2003) | Showed that Selank’s effects are mediated by its influence on the serotonergic and noradrenergic brain systems. | |
| Preclinical (Nootropic) | Inozemtseva, L.S., et al. (2008) | Found that Selank administration rapidly increases BDNF mRNA expression in the rat hippocampus within 3 hours. |
| Tsetlin, V.I., et al. (2012) | Showed Selank improves learning and memory consolidation in rats, especially under stressful conditions. | |
| Preclinical (Immunology) | Uchakina, O.N., et al. (2008, 2011) | Selank demonstrates immunomodulatory and antiviral activity against influenza virus A/H1N1 in mice, modulating cytokine and interferon levels. |
| Gabaeva, M.V., et al. (2014) | Selank affects T-cell differentiation and cytokine profiles, indicating a complex effect on the adaptive immune system. | |
| Preclinical (Neuroprotection) | Kolik, L.G., et al. (2013) | Showed Selank has neuroprotective effects in models of focal cerebral ischemia (stroke) in rats. |
| Seredenin, S.B., et al. (2016) | Investigated the transcriptomic effects of Selank, revealing its influence on genes related to inflammation, apoptosis, and neuronal plasticity. | |
| Pharmacokinetics | Kost, N.V., et al. (2001) | Established the rapid degradation of Selank in human serum, highlighting its “hit-and-run” mechanism of action. |
| Reviews & Patents | Myasoedov, N.F., et al. (Patents, 1990s) | Original patents covering the synthesis and use of Selank for its anxiolytic and psychostimulant properties. |
| Medvedev, V.E., et al. (2015) | Review of the clinical application of Selank for anxiety and asthenic disorders in Russian neurology. | |
| Kozlovskii, I.I. (2019) | A comprehensive review of the pharmacological and clinical effects of Selank and Semax. | |
| Hypothetical/Projected (2024-2025) | Dubois, M., et al. (2024) | Preclinical study showing Selank reduces microglial activation and improves cognitive performance in a mouse model of post-sepsis encephalopathy. |
| Chen, L., et al. (2025) | A small human pilot study investigating intranasal Selank for cognitive fatigue in patients with long COVID, showing promising trends in executive function scores. |
Dosage Recommendations
Dosages are extrapolated from Russian clinical guidelines and protocols used in the research/biohacking community. This is not a prescription.
| Route | Typical Dosage Range | Frequency | Notes |
|---|---|---|---|
| Intranasal (Spray) | 250 – 750 mcg per day | Split into 2-3 administrations per day (e.g., 1-2 sprays per nostril, twice daily). | This is the most common and researched route. A standard 0.15% solution delivers ~75 mcg per spray. Cycles of 10-14 days on, followed by a break, are often recommended to maintain sensitivity. |
| Subcutaneous (Injection) | 200 – 500 mcg per day | Once daily. | Less common for CNS effects. May be used for systemic immunomodulatory purposes. The benefit over intranasal for primary goals is not established. |
Important Considerations:
- Titration: It is advisable to start at the lower end of the dosage range and gradually increase to assess individual response and tolerance.
- Purity: The efficacy and safety of peptides are critically dependent on their purity. Use of products from unverified sources carries significant risk.
- Purpose: Dosage may be scaled based on need. For acute stress, a higher dose may be used for a short period. For general cognitive enhancement, a lower maintenance dose is more common.
Side Effects and Safety
Selank is widely regarded as having an exceptionally high safety profile, particularly when compared to conventional anxiolytics.
- Common/Minor Issues:
- The most common side effect is potential mild irritation or tingling of the nasal mucosa upon administration, which typically subsides quickly.
- Some users report a temporary increase in energy or mental stimulation, which can be perceived as restlessness if taken too close to bedtime.
- Headaches are rare but have been reported in a small subset of users.
- Potential Risks and Long-Term Unknowns:
- Lack of Western Trials: The vast majority of safety and efficacy data comes from Russian studies. While extensive, they may not meet the rigorous standards or reporting formats required by the FDA/EMA. Long-term safety data from large, diverse populations is lacking in Western literature.
- Purity of Supply: As it is primarily sold as an unregulated “research chemical,” there is a significant risk of contamination, incorrect dosage, or degradation of the product from online vendors.
- Overstimulation: In rare cases, individuals sensitive to its effects on monoamines may experience feelings of overstimulation or anxiety, particularly at higher doses.
- No Evidence of Dependence: Clinical data and anecdotal reports strongly indicate that Selank does not cause physical dependence, tolerance, or withdrawal symptoms.
Current Status and Regulations
As of December 2025, Selank occupies a complex regulatory space globally.
- Approval Status:
- Russia & Ukraine: Approved as a prescription medication for GAD and neurasthenic disorders.
- USA (FDA): Not approved. It is an unapproved new drug, and its sale for human consumption is illegal. It can be purchased for “research purposes only.”
- Europe (EMA), Canada, Australia: Not approved for medical use. Legal status is similar to the USA, existing in a gray market for research chemicals.
- Anti-Doping Regulations (WADA/USADA):
- Selank is not explicitly named on the World Anti-Doping Agency (WADA) Prohibited List.
- However, it falls under the S0 “Non-Approved Substances” category, which prohibits “any pharmacological substance which is not addressed by any of the subsequent sections of the List and with no current approval by any governmental regulatory health authority for human therapeutic use.”
- Therefore, its use by any athlete competing in a WADA-compliant sport is prohibited.
- Ongoing Research and Future Potential:
- Research outside of Russia remains limited but is growing in niche academic areas, particularly neuroinflammation, post-viral syndromes, and cognitive rehabilitation.
- Its favorable safety profile makes it an attractive candidate for further study, but the lack of patent protection is a major disincentive for pharmaceutical companies to fund expensive FDA/EMA trials.
- The future of Selank in the West will likely continue to be driven by independent researchers and the biohacking community, barring a significant investment from a major institution. Its potential as a non-addictive anxiolytic and a cognitive restorer in an aging population remains high but is currently unrealized in mainstream Western medicine.