Selank: Anxiolytic Neuropeptide
A synthetic heptapeptide derived from tuftsin, studied for anxiolytic and immunomodulatory effects.
Quick Reference
| Research Dosage | 250-500mcg per day |
|---|---|
| Frequency | 1-3 times daily |
| Administration | Intranasal (common), subcutaneous |
| Cycle Length | 14-21 days typical |
| Reconstitution | 2mL bacteriostatic water per vial |
| Storage | Refrigerate after reconstitution, use within 3-4 weeks |
While its companion peptide Semax focuses on cognition and neuroprotection, Selank targets something equally important: anxiety and mood regulation. Developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, Selank is an approved pharmaceutical in Russia – prescribed for anxiety disorders and neurasthenia since the early 2000s.
Selank was created by combining tuftsin (an immunomodulatory peptide fragment naturally derived from IgG antibodies) with a stabilising sequence. This dual origin gives Selank unique properties: it affects both the nervous system (anxiolytic effects) and the immune system (immunomodulation), making it particularly interesting for research into the bidirectional connections between stress, immunity, and mental health.
What distinguishes Selank from conventional anxiolytics is its mechanism – it enhances GABA system function without directly binding to GABA-A receptors like benzodiazepines do. Research suggests this produces anxiolytic effects without the sedation, dependence, or tolerance issues associated with benzodiazepine use.
Research Applications
Selank is studied across multiple domains of neuroscience, psychiatry, and immunology:
Anxiety and Mood Research
GABAergic System Effects
Research shows Selank significantly modulates the GABA (gamma-aminobutyric acid) system:
- Enhances GABA receptor activity without direct agonism
- Affects GABA-A receptor subunit expression (particularly α2 and α6)
- May inhibit GABA-degrading enzymes
- Increases effectiveness of endogenous GABA signalling
This GABAergic enhancement is central to Selank's anxiolytic effects in research models. The mechanism differs fundamentally from benzodiazepines.
Clinical Anxiety Research
Russian clinical studies have examined Selank in:
- Generalised anxiety disorder (GAD)
- Neurasthenia (nervous exhaustion)
- Adjustment disorders with anxiety
- Anxiety comorbid with cognitive impairment
- Chronic stress conditions
Stress Response Modulation
Studies have investigated Selank's effects on:
- Acute stress responses (behavioural and physiological)
- Chronic stress adaptation
- Stress-induced cognitive impairment
- HPA axis modulation (cortisol, ACTH)
- Stress resilience and recovery
Cognitive Effects
While less prominent than Semax, Selank demonstrates cognitive effects:
Memory Under Stress
Research suggests Selank protects cognitive function during stressful conditions:
- Anxiety typically impairs memory and attention
- Selank may maintain cognitive performance under stress
- Relevant for anxiety-cognitive dysfunction overlap
BDNF Expression
Like Semax, Selank increases BDNF expression, though the effect profile differs:
- Moderate BDNF upregulation documented
- May contribute to cognitive effects
- Potential role in neuroplasticity
Immunomodulation Research
Selank's tuftsin origin gives it unique immunomodulatory properties:
Tuftsin Background
Tuftsin (Thr-Lys-Pro-Arg) is a naturally occurring tetrapeptide:
- Derived from the Fc region of IgG antibodies
- Stimulates phagocytosis (immune cell "eating" of pathogens)
- Enhances natural killer cell activity
- Modulates cytokine production
Selank incorporates this tuftsin sequence, retaining immunomodulatory activity.
Psychoneuroimmunology Applications
The overlap between Selank's anxiolytic and immune effects makes it valuable for studying:
- How stress affects immunity
- How immune activation affects mood
- Bidirectional brain-immune communication
- Inflammatory contributions to anxiety/depression
Dosage Information
Standard Research Dosages
Dosages commonly referenced in Russian clinical literature range from 250-500mcg per day, administered in 1-3 divided doses.
Dosing Protocols
Conservative: 250mcg once or twice daily
Standard: 250mcg three times daily (~750mcg total) or 400-500mcg twice daily
Administration Routes
Intranasal Administration
- Most common route in Russian clinical practice
- 0.15% nasal spray solution is standard formulation
- Rapid absorption through nasal mucosa
- Potential direct CNS access via olfactory pathway
Subcutaneous Injection
- Alternative research route
- Systemic absorption
- May have different pharmacokinetic profile
Cycle Duration
Research protocols typically run 14-21 days:
- Effects develop over first week
- Peak effects during second and third weeks
- Follow with break period before repeating
Timing Considerations
Unlike Semax (which may be alerting), Selank's anxiolytic effects allow flexible timing:
- Morning: Addresses daytime anxiety
- Multiple daily doses: Maintains steady effects
- Evening: May help with evening anxiety (no reported sedation)
Reconstitution Guide
Required Materials
- Selank lyophilised powder
- Bacteriostatic water
- Sterile syringe
- Alcohol swabs
Reconstitution Steps
- Allow vial to reach room temperature
- Draw 2mL bacteriostatic water into syringe
- Add water slowly, directing stream down inside vial wall
- Allow to dissolve without shaking – Selank typically dissolves readily
- Store refrigerated at 2-8°C
Concentration Reference Table
| Vial Size | Water Added | Concentration | 250mcg Dose | 500mcg Dose |
|---|---|---|---|---|
| 5mg | 2mL | 2.5mg/mL | 10 units (0.1mL) | 20 units (0.2mL) |
| 10mg | 2mL | 5mg/mL | 5 units (0.05mL) | 10 units (0.1mL) |
Storage Guidelines
Lyophilised (Powder) Form
- Long-term: -20°C (freezer)
- Short-term: 2-8°C (refrigerator)
- Protect from light and moisture
- Stable for extended periods when stored properly
Reconstituted Solution
- Must be refrigerated at 2-8°C
- Use within 3-4 weeks
- Use sterile technique when drawing doses
- Discard if solution becomes cloudy
Selank vs Semax: Detailed Comparison
Both are Russian-developed heptapeptide nootropics – understanding their differences helps select the appropriate peptide for specific research applications:
| Aspect | Selank | Semax |
|---|---|---|
| Derived From | Tuftsin (immune peptide) | ACTH(4-10) (hormonal fragment) |
| Sequence | TKPRPGP | MEHFPGP |
| Molecular Weight | 751.9 Da | 813.97 Da |
| Primary Effect | Anxiolytic, mood stabilising | Nootropic, neuroprotective |
| GABA Effects | Strong enhancement | Minimal |
| Dopamine Effects | Moderate | Strong |
| BDNF Effects | Moderate upregulation | Strong upregulation |
| Immune Effects | Significant (tuftsin) | Modest |
| Anxiolytic | Primary effect | Secondary effect |
| Sedation | None at standard doses | None |
| Russian Approval | Anxiety, neurasthenia | Stroke, cognitive disorders |
Complementary Research Use
Many researchers study Selank and Semax together:
- Selank addresses anxiety/mood component
- Semax addresses cognition/neuroprotection
- Complementary mechanisms without overlap
- No reported negative interactions
- May provide broader benefit profile than either alone
Selank vs Benzodiazepines
Research comparing Selank to traditional anxiolytics reveals important differences:
| Property | Selank | Benzodiazepines |
|---|---|---|
| Mechanism | Enhances endogenous GABA function | Direct GABA-A receptor agonism |
| Anxiolytic Effect | Comparable in some models | Well-established |
| Sedation | Minimal/none at standard doses | Significant, dose-dependent |
| Cognitive Effects | May improve (esp. under stress) | Impairs memory, attention |
| Dependence | Not observed in studies | Well-documented risk |
| Tolerance | Not observed | Develops with chronic use |
| Withdrawal | Not reported | Can be severe |
| Psychomotor Impairment | Not observed | Significant |
This comparison profile makes Selank attractive for anxiety research where benzodiazepine side effects are problematic.
Frequently Asked Questions
Common questions about Selank research
What is Selank?
Selank is a synthetic heptapeptide (7 amino acids) derived from tuftsin, an immunomodulatory peptide naturally found in the body. Developed in Russia, it is approved there as a pharmaceutical for anxiety disorders and neurasthenia. Research focuses on its anxiolytic (anti-anxiety) properties, which appear mediated through GABA system enhancement and immunomodulation.
Is Selank approved anywhere?
Yes. Selank is approved as a pharmaceutical medication in Russia for anxiety disorders and neurasthenia (nervous exhaustion). It has been prescribed clinically since the early 2000s. It is not approved by the FDA, TGA, or European regulatory agencies.
What is the difference between Selank and Semax?
Both are Russian neuropeptides, but with different primary effects. Selank is derived from tuftsin (immune peptide), is primarily anxiolytic and immunomodulatory, and works through GABA enhancement. Semax is derived from ACTH (hormone fragment), is primarily nootropic and neuroprotective, and works through dopamine and BDNF. They are complementary rather than interchangeable.
Does Selank cause sedation like benzodiazepines?
Research indicates Selank produces anxiolytic effects without significant sedation at standard doses. This differs from benzodiazepines, which typically cause dose-dependent sedation. The mechanism difference (GABA enhancement vs. direct agonism) likely explains this.
Is Selank addictive?
Research has not identified dependence liability with Selank. No tolerance development or withdrawal effects have been reported in published studies. This contrasts with benzodiazepines, which carry well-documented dependence risks.
Can Selank be used with Semax?
Research has examined both peptides without documented negative interactions. They have complementary mechanisms – Selank for anxiety/mood through GABA, Semax for cognition/neuroprotection through dopamine and BDNF. Some protocols use both concurrently.
How does Selank affect the immune system?
Through its tuftsin component, Selank has immunomodulatory effects: it modulates cytokine expression, affects immune cell activity, may influence inflammatory balance, and is relevant for psychoneuroimmunology research.
What is the onset of effects with Selank?
Anxiolytic effects may begin within days of starting administration. Full effects typically develop over 1-2 weeks of consistent use. Most research protocols run 14-21 days.
What is the molecular weight of Selank?
Selank has a molecular weight of 751.9 g/mol (Da).
The Science: How Selank Works
Origin: Tuftsin Plus Stabilisation
Selank combines two components:
Tuftsin (Thr-Lys-Pro-Arg)
- Natural tetrapeptide derived from IgG heavy chain
- Produced by spleen enzymatic cleavage
- Potent stimulator of phagocytosis
- Enhances immune cell activity
- Very short half-life in natural form (minutes)
Stabilising Sequence (Pro-Gly-Pro)
- Added to C-terminus of tuftsin
- Dramatically increases resistance to enzymatic degradation
- Extends biological half-life
- Same stabilisation approach used in Semax
The result: A peptide with tuftsin's immunomodulatory properties plus anxiolytic effects, with improved stability.
Mechanisms of Action
1. GABAergic System Enhancement (Primary Anxiolytic Mechanism)
Selank enhances GABA neurotransmission without directly activating GABA receptors:
How This Differs From Benzodiazepines:
- Benzodiazepines: Bind directly to GABA-A receptors, potentiating response to GABA
- Selank: Enhances overall GABA system function through multiple mechanisms
Documented GABAergic Effects:
- Affects GABA-A receptor subunit expression (α2, α6 subunits)
- May inhibit GABA transaminase (enzyme that breaks down GABA)
- Increases endogenous GABA effectiveness
- Enhances GABAergic tone without direct receptor activation
The indirect enhancement mechanism may explain why Selank produces anxiolytic effects without the sedation, dependence, and tolerance associated with direct GABA-A agonism.
2. Serotonin and Dopamine Modulation
Research shows Selank affects monoamine neurotransmitter systems:
Serotonin:
- Influences serotonin metabolism
- Affects 5-HT receptor expression
- May contribute to mood stabilisation
- Relevant to anxiety-depression overlap
Dopamine:
- Modulates dopamine turnover
- Affects dopamine receptor expression
- Less pronounced than Semax's dopamine effects
- May contribute to motivation and reward aspects
3. Enkephalin System Effects
Studies suggest Selank interacts with endogenous opioid systems:
- May inhibit enkephalin-degrading enzymes
- Prolongs endogenous enkephalin activity
- Enkephalins have natural anxiolytic and analgesic effects
- Could contribute to mood-elevating properties
4. Neurotrophic Effects
Selank increases expression of neurotrophins:
BDNF (Brain-Derived Neurotrophic Factor):
- Moderate upregulation in hippocampus and cortex
- Supports neuronal survival and plasticity
- May underlie cognitive protection under stress
- Less pronounced than Semax but still significant
5. Immunomodulation (Via Tuftsin Component)
The tuftsin core provides immunomodulatory effects:
Cytokine Modulation:
- Affects balance of pro-inflammatory and anti-inflammatory cytokines
- May reduce excessive inflammation
- Modulates IL-6, TNF-α, and other cytokines
Psychoneuroimmunology Relevance:
These immune effects connect to anxiety through:
- Inflammatory contributions to anxiety/depression
- Stress-induced immune suppression
- Bidirectional brain-immune communication
- Cytokine effects on mood and behaviour
Amino Acid Sequence and Structure
Full Sequence (Three-Letter Code): Thr-Lys-Pro-Arg-Pro-Gly-Pro
Single-Letter Code: TKPRPGP
Structural Features
Tuftsin Core (Positions 1-4):
- TKPR is the natural tuftsin sequence
- Contains two positive charges (K, R)
- Responsible for immunomodulatory activity
- Receptor binding domain
Pro-Gly-Pro Extension (Positions 5-7):
- Added for stability enhancement
- Same sequence used in Semax
- Protects against aminopeptidases and carboxypeptidases
- Dramatically extends biological half-life
Technical Specifications
| Systematic Name | Selank |
|---|---|
| Other Names | Selanc, TP-7, Tuftsin Analogue, TKPRPGP, Selank Acetate |
| Amino Acid Count | 7 |
| Sequence | TKPRPGP |
| Molecular Formula | C33H57N11O9 |
| Molecular Weight | 751.9 g/mol |
| CAS Number | 129954-34-3 |
| Isoelectric Point | ~10 |
| Net Charge (pH 7) | +2 |
| Appearance | White to off-white lyophilised powder |
| Solubility | Freely soluble in water and aqueous buffers |
| Purity (PurposeLabs) | ≥99% (HPLC verified) |
| Storage (Lyophilised) | -20°C long-term, 2-8°C short-term |
| Storage (Reconstituted) | 2-8°C, use within 4-6 weeks |
Quality: Australian University Testing
Why Peptide Quality Matters
The research peptide market contains products of highly variable quality. Independent testing of products from various suppliers has revealed significant issues:
- Purity levels as low as 50% in products claiming "99% purity"
- Incorrect amino acid sequences (entirely wrong peptides)
- Truncated sequences (missing amino acids)
- Bacterial endotoxin contamination
- Oxidised or degraded peptides with reduced activity
Our Testing Protocol
Every batch of Selank from PurposeLabs undergoes comprehensive testing at a leading proteomics laboratory based at an Australian university in Sydney – one of Australia's premier analytical facilities.
Confirms purity levels of ≥99%, identifies any impurities or degradation products.
Verifies exact molecular weight, confirms correct amino acid sequence.
Determines actual peptide content versus salt, moisture, and counter-ions.
Why Australian University Testing?
Our testing partner is an established, verifiable proteomics facility at a major Australian university, with published research credentials, transparent methodology, and no commercial conflict of interest. This contrasts with overseas "certificates of analysis" from unknown or unverifiable laboratories.
Shop Selank
Australian university tested. 99%+ purity verified by HPLC and mass spectrometry. Fast shipping from Sydney.
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References
Key studies for researchers seeking primary literature:
- Seredenin SB, et al. "Anxiolytic action of tuftsin analogue selank." Bulletin of Experimental Biology and Medicine, 1998.
- Zozulia AA, et al. "Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia." Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2008.
- Kolik LG, et al. "Selank, a peptide analogue of tuftsin, inhibits the development of tolerance to the analgesic effect of morphine." Bulletin of Experimental Biology and Medicine, 2008.
- Kolomin T, et al. "Transcriptomic response of rat hippocampus and spleen to single and repeated administration of Semax and Selank." Frontiers in Neuroscience, 2013.
- Uchakina ON, et al. "Immunomodulatory effects of selank in patients with anxiety-asthenic disorders." Zhurnal Nevrologii i Psikhiatrii, 2008.
- Kasian A, et al. "Selank administration affects gene expression in the rat brain." Molecular Biology, 2017.
- Volkova A, et al. "Selank modulates the expression of cytokine genes in rat hypothalamus." Doklady Biochemistry and Biophysics, 2009.
Disclaimer
All products sold by PurposeLabs are intended for laboratory and research use only. They are not intended for human or animal consumption. The information provided is for educational purposes only and should not be construed as medical advice. Consult with qualified healthcare professionals for any health-related decisions.
Selank is not approved by the TGA for therapeutic use in Australia. Products are sold strictly for research purposes in accordance with Australian regulations.