Selank Nasal Spray vs Injection
Selank has been primarily investigated as a peptide administered intranasally, with the majority of published scientific literature focusing on nasal administration rather than injection. The intranasal route of administration was deliberately chosen during the peptide's development, as it may facilitate access to the central nervous system via the olfactory and trigeminal pathways. This allows Selank to potentially impact brain function while bypassing extensive systemic metabolism [1,2]. Studies evaluating the effects of Selank on anxiety, neurochemistry, gene expression, and the regulation of brain-derived neurotrophic factor (BDNF) have predominantly used intranasal administration [2–5].
For comparison, very few clinical studies have been published on subcutaneous or intramuscular injections of Selank. Although injectable preparations are available from some peptide suppliers, there is currently insufficient clinical data to conclude that injections provide better effects in terms of anxiety reduction, improved cognitive function, or other potential applications. Since most mechanistic and clinical studies have been conducted using intranasal Selank, this route of administration currently has the strongest scientific evidence [2–6].
Is Selank Better Used as a Nasal Spray or in Injectable Form?
Currently, there are no high-quality studies directly comparing intranasal and injectable Selank in humans.
From an evidence-based medicine perspective, intranasal administration offers several significant advantages. The majority of published clinical trials have utilised this route of administration, and animal studies demonstrating changes in BDNF expression and neurochemical regulation have also relied on intranasal delivery. Furthermore, it is a non-invasive method and has been specifically developed for the delivery of peptides to the brain [2–5].
Injectable administration could theoretically lead to different pharmacokinetic properties and varying systemic exposure. However, potential differences have not been adequately investigated in controlled clinical trials. Therefore, there is currently no evidence to suggest that injections are more effective than nasal administration.
Comparison of Selank Nasal Spray and Injection
| Feature | Nasal Selank | Selank Injection |
|---|---|---|
| Human clinical trials | The most available data | Very limited data |
| Neurobiological research on animals | Extensive | Limited |
| Non-invasive route of administration | Yes | Not |
| Potential for direct brain intervention | Yes | Uncertain |
| BDNF Research | Yes | Poorly researched |
| Anxiety research | Yes | Insufficient data |
| Long-term safety data | Limited | Very limited |
Scientific Conclusions
Based on currently available data, intranasal Selank is the best-researched route of administration and remains the form most frequently used in published scientific studies. Injectable Selank may have theoretical potential applications, but there is currently insufficient evidence to determine whether it offers any advantages over intranasal administration.
Selank Stability and Shelf Life
Selank is a synthetic heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) composed of amino acids that can gradually degrade under adverse environmental conditions such as high temperature, humidity, repeated freeze-thaw cycles, and prolonged storage in solution [7].
Like many other peptides, the stability of Selank primarily depends on temperature, storage conditions, light exposure, the presence of moisture, and whether the product remains in lyophilised form or has already been reconstituted.
Does Selank Require Refrigeration?
Unreconstituted Lyophilised Powder
Lyophilised peptide powder is generally more stable than peptides stored in solution. Manufacturers often recommend storing unopened peptide vials at 2–8°C, away from light, and in a dry environment.
Some freeze-dried peptides may retain stability for a longer time when stored in a refrigerator, however, precise data regarding the stability of Selank is still limited.
Dissolved Selank
After dissolution using bacteriostatic water or another solvent, peptide degradation can accelerate. Therefore, it is recommended to store at 2–8°C, avoid excessive heat, limit temperature fluctuations and avoid multiple freeze-thaw cycles.
How long can Selank be stored once dissolved?
No stability studies have currently been published that determine the exact shelf-life of dissolved Selank.
Because peptide degradation in solution can occur over time, peptide laboratories often recommend using dissolved preparations within a few weeks while storing them in the refrigerator. However, these recommendations are mainly based on general peptide handling principles rather than on direct stability studies conducted specifically for Selank.
Therefore, at present, it is not possible to determine a specific expiry date with full certainty based on the available scientific evidence.
Scientific Conclusions
Selank appears to be subject to the typical stability rules for therapeutic peptides. Refrigeration is generally recommended after reconstitution, however, the precise stability period for reconstituted Selank has not been determined in published clinical studies.
Selank in Powder, Nasal Spray, and Vials
Selank is most commonly available in three basic forms: lyophilised powder, vials of peptide, and nasal spray preparations.
Selank Powder
Selank in powder form typically refers to the peptide in a lyophilised (freeze-dried) state. The lyophilisation process removes water, improving stability during storage and transport. The powder itself is not directly administered and usually requires reconstitution before use.
Freeze-dried peptides are widely used because dry preparations generally retain greater stability than peptides stored in solution.
Vials of Selank
The term „Selank vial” most commonly refers to containers holding lyophilised powder requiring reconstitution or ready-to-use liquid preparations.
The concentration and intended purpose of the product depend on the manufacturer and specific formulation. Published scientific studies usually describe the peptide itself, not specific commercial products.
Selank Nasal Spray
Nasal spray with Selank is the best-researched form in the scientific literature. Numerous studies concerning anxiety, neurochemical modulation, gene expression, and neurotrophic activity have utilised nasal administration [2–5].
Nasal administration is particularly interesting because peptides delivered via the nasal cavity can partially bypass degradation in the gastrointestinal tract and potentially access the central nervous system via olfactory pathways.
Scientific Conclusions
Of the currently available forms, intranasal Selank has the strongest scientific basis, while the powder and vials are primarily pharmaceutical forms used to prepare the peptide for administration.
What forms of Selank are available?
Selank is offered and discussed in several different forms, although not all have been extensively studied scientifically.
Selank Nasal Spray
Nasal Selank is the best-researched form and has been used in both human and animal studies for anxiety disorders, cognitive function, neurotransmitter modulation, BDNF expression, and stress response [2–6].
Selank Injection
Injectable preparations are commercially available, however, published data on their efficacy, pharmacokinetics and safety are very limited compared to nasal administration.
Selank Drops
Terms Selank drops i Selank nasal drops are sometimes used interchangeably with nasal spray. Both methods are based on the intranasal administration of dissolved peptide preparations.
Selank tablets
Currently, there are very few scientific publications concerning oral Selank tablets. As peptides are usually prone to degradation in the gastrointestinal tract, oral administration presents significant formulation challenges.
Scientific Conclusions
| Shape | Science Facts |
|---|---|
| Nasal spray | The strongest scientific foundations |
| Nasal drops | Similar reasoning to nasal spray |
| Injectable preparations | Limited data |
| Freeze-dried powder | Pharmaceutical form before preparation |
| Pills | Little or no published data |
Most studies confirming Selank's potential neurobiological effects have been conducted using nasal administration, which is why this route of administration currently has the strongest support in the scientific literature.
Disclaimer
The content is for educational and informational purposes only and does not constitute medical advice, diagnosis, therapy, or recommendations for use. Selank has not been approved by the US Food and Drug Administration (FDA) or the European Medicines Agency (EMA) for the treatment of anxiety disorders, cognitive disorders, or any other conditions. Most available data comes from preclinical studies and limited human trials, many of which used a nasal administration route. Information regarding storage, stability, and alternative forms of the preparation is for educational purposes only and should not be interpreted as official usage recommendations.
References
[1] PubChem. (2026). Selank (CID: 11765600). National Centre for Biotechnology Information. https://pubchem.ncbi.nlm.nih.gov/compound/Selank
[2] Levitskaya, N. G., Andreeva, L. A., Mezentseva, M. V., Shapoval, I. M., Podchernyaeva, R. Y., Shcherbenko, V. E., Potapova, L. A., Russu, L. I., Ershov, F. I., & Myasoedov, N. F. (2010). Intranasal administration of the peptide Selank regulates BDNF expression in the rat hippocampus in vivo. Doklady Biological Sciences, 431, 79–82.
[3] Vyunova, T. V., Andreeva, L., Shevchenko, K., & Myasoedov, N. F. (2018). Peptide-based anxiolytics: The molecular aspects of heptapeptide Selank biological activity. Protein and Peptide Letters, 25(10), 914-923. https://doi.org/10.2174/0929866525666180925144642
[4] Zozulia, A. A., Neznamov, G. G., Siuniakov, T. S., Kost, N. V., Gabaeva, M. V., Sokolov, O. Y., Serebriakova, E. V., Siranchieva, O. A., Andriushenko, A. V., Telesheva, E. S., Siuniakov, S. A., Smulevich, A. B., Myasoedov, N. F., & Seredenin, S. B. (2008). Efficacy and possible mechanisms of action of a new peptide anxiolytic Selank in the therapy of generalised anxiety disorders and neurasthenia. The Korsakov Journal of Neurology and Psychiatry, 108(4), 38-48. https://pubmed.ncbi.nlm.nih.gov/18454096/
[5] Andreeva, L. A., Nagaev, I. Y., Mezentseva, M. V., Shapoval, I. M., Podchernyaeva, R. Y., Shcherbenko, V. E., Potapova, L. A., Russu, L. I., Ershov, F. I., & Myasoedov, N. F. (2010). Antiviral properties of structural fragments of the peptide Selank. Doklady Biological Sciences, 431, 79–82. https://doi.org/10.1134/S0012496610020031
[6] Zozulya, A. A., Kost, N. V., Sokolov, O. Y., Gabaeva, M. V., Grivennikov, I. A., Andreeva, L. N., Zolotarev, Y. A., Ivanov, S. V., Andryushchenko, A. V., Myasoedov, N. F., & Smulevich, A. B. (2001). The inhibitory effect of Selank on enkephalin-degrading enzymes as a possible mechanism of its anxiolytic activity. Bulletin of Experimental Biology and Medicine, 131, 315–317. https://doi.org/10.1023/A:1017979514274
[7] PubChem. (2026). Selank: Chemical and Physical Properties. National Library of Medicine. https://pubchem.ncbi.nlm.nih.gov/compound/Selank