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Last reviewed: 2026-05-29
Evidence standard: Claims graded by direction and confidence below. Speculation is labeled.
Conflict of interest: FormBlends sells research compounds. We disclose this and still report negative or uncertain evidence.
This page is not medical advice. Selank is not FDA-approved. Consult a licensed clinician before use.
Key Takeaways
- Selank is a heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) registered in Russia as a 0.15% nasal spray; that approved concentration is 1.5 mg per mL, delivering roughly 150 to 300 mcg per actuation depending on device volume.
- Bacteriostatic water (0.9% benzyl alcohol) is the preferred diluent for DIY preparation because benzyl alcohol inhibits gram-positive and gram-negative bacterial growth, extending usable refrigerator life beyond that of plain sterile saline.
- Your atomizer's actual spray volume drives all dosing math; verify it by weighing 10 actuations over a tared container (1 mL of water weighs 1 gram) before loading peptide solution.
- Home preparations cannot achieve pharmaceutical sterility; nasal mucosal infection risk is lower than with injections but not zero, and improperly prepared solutions have caused sinus infections in self-reported community cases.
- Independent Western RCT data for Selank do not exist; existing human evidence comes from small Russian clinical trials, placing overall confidence at Low by GRADE criteria.
Direct Answer: How Do You Make Selank Nasal Spray?
To make Selank nasal spray, dissolve lyophilized Selank powder in bacteriostatic water to a target concentration of 2 to 3 mg per mL, draw the solution into a sterile low-dead-volume nasal atomizer calibrated to 0.1 mL per actuation, and refrigerate at 2 to 8 degrees Celsius. Each 0.1 mL spray then delivers 200 to 300 mcg. Verify your atomizer volume before loading.
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- Evidence Ledger: What Does the Science Actually Support?
- How Selank Works and Why the Nasal Route Is Used
- What Diluent Should You Use?
- Reconstitution Math: Step-by-Step Calculation
- Choosing and Verifying Your Nasal Atomizer
- What Most Pages Get Wrong About Selank Nasal Spray
- Stability, Storage, and When to Discard
- Honest Head-to-Head: Nasal Spray vs. Subcutaneous Injection
- Label and COA Literacy: Judging Your Source
- FAQ
- Sources
Evidence Ledger: What Does the Science Actually Support?
| Claim | Best Evidence Type | Effect Direction | Confidence (GRADE) |
|---|---|---|---|
| Selank reduces anxiety in humans via intranasal route | Small Russian clinical trials (n typically under 100, limited blinding detail) | Positive, modest | Low |
| Selank modulates GABA-A receptor function | In vitro and rodent pharmacology | Positive (potentiating) | Low to Moderate (mechanism plausible, human translation unproven) |
| Selank affects BDNF expression in rodents | Animal (rat) studies | Positive | Low (animal only) |
| Intranasal peptides can reach CNS via olfactory pathway | Human pharmacokinetic studies for other peptides; mechanistic | Positive (route exists) | Moderate (class evidence; Selank-specific PK data are very limited) |
| Bacteriostatic water extends peptide solution shelf life vs. plain saline | Pharmaceutical compounding literature and USP guidance | Positive | Moderate |
| DIY nasal spray carries contamination risk | Mechanism and case reports in compounding literature | Risk present | Moderate |
How Selank Works and Why the Nasal Route Is Used
Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is a synthetic analogue of the endogenous tetrapeptide tuftsin (Thr-Lys-Pro-Arg). Russian researchers at the Institute of Molecular Genetics developed it specifically to be more metabolically stable than tuftsin by appending the Pro-Gly-Pro sequence, which slows enzymatic cleavage. Published rodent data indicate that Selank inhibits enkephalin-degrading enzymes, increasing endogenous opioid peptide half-life locally, and modulates GABA-A receptor activity in a pattern distinct from benzodiazepines.
The nasal route is used for three practical reasons. First, the olfactory and trigeminal nerve endings in the nasal mucosa provide a pathway to bypass the blood-brain barrier for small polar molecules, a route documented for several neuropeptides. Second, the approved Russian commercial product is itself a nasal spray (0.15% solution), establishing clinical precedent. Third, peptides are poorly orally bioavailable because gastric proteases degrade them rapidly; injection and intranasal delivery are the two meaningful alternatives.
What the mechanism does NOT prove: demonstrating GABA modulation in rodent brain slices or CNS deposition of a labeled tracer in rats does not confirm that a homemade Selank nasal spray in a human will produce a measurable anxiolytic effect at a given dose. Extrapolation requires caution.
What Diluent Should You Use?
The choice of diluent affects sterility, peptide stability, and mucosal tolerability.
| Diluent | Preservative | Practical Shelf Life (Refrigerated) | Notes |
|---|---|---|---|
| Bacteriostatic water (0.9% benzyl alcohol in sterile water for injection) | Yes, benzyl alcohol 0.9% | Up to 4 weeks (researcher convention; not formally validated for Selank) | Most common choice; benzyl alcohol at 0.9% is bacteriostatic, not bactericidal |
| Sterile 0.9% NaCl (normal saline) | No | 24 to 48 hours once opened | Isotonic, mucosal-friendly pH; discard quickly |
| Sterile water for injection | No | 24 hours | Hypotonic; can cause mucosal irritation; not preferred |
| Tap or distilled water | No | Not suitable | Non-sterile; never use |
Why bacteriostatic water is preferred: Benzyl alcohol at 0.9% disrupts bacterial cell membrane integrity and denatures surface proteins, inhibiting replication of most gram-positive and gram-negative contaminants. It does not fully sterilize an already-contaminated solution but suppresses growth during the weeks of refrigerated use. The USP chapter on antimicrobial effectiveness testing requires preserved products to meet specific log-reduction criteria; home preparations cannot be tested against this standard, but the preservative still provides meaningful protection over unpreserved diluents.
Reconstitution Math: Step-by-Step Calculation
Before you start, confirm your atomizer's spray volume (see the next section). This example uses a 0.1 mL per actuation device and a 5 mg vial of Selank.
| Step | Action | Example |
|---|---|---|
| 1 | Decide target dose per spray | 300 mcg (0.3 mg) per actuation |
| 2 | Calculate required concentration | 0.3 mg per 0.1 mL = 3 mg per mL |
| 3 | Calculate diluent volume for your vial | 5 mg divided by 3 mg/mL = 1.67 mL diluent |
| 4 | Add diluent slowly to vial, swirl gently, do not shake | Draw 1.67 mL bacteriostatic water in a sterile syringe; inject into vial |
| 5 | Verify solution is clear and colorless | Discard if cloudy or particulate |
| 6 | Transfer to nasal atomizer with fresh sterile syringe | Load atomizer; prime with 2 actuations into waste |
| 7 | Double-check math | 1.67 mL total divided by 0.1 mL/spray = 16 to 17 sprays at 300 mcg each |
Choosing and Verifying Your Nasal Atomizer
Most commodity spray bottles marketed online deliver 0.05 to 0.15 mL per actuation with no consistent calibration. Using an uncalibrated device makes dosing math meaningless.
What to look for: Devices designed for pharmaceutical intranasal delivery specify actuation volume (commonly 0.1 mL or 0.14 mL) and droplet/particle size. For nasal mucosal deposition rather than deep lung deposition, a mass median aerodynamic diameter (MMAD) below 100 microns is appropriate. Devices such as the Aptar UDS (unit-dose system) or similar calibrated nasal atomizers meet this standard. The MAD Nasal atomizer used clinically by emergency medicine providers delivers approximately 0.1 mL per actuation when used with a 1 mL syringe.
How to verify volume at home: Place a tared container on a digital scale. Actuate the empty atomizer 10 times into the container with your planned fill volume of water. Divide total mass in grams by 10 to get mL per actuation (water density is approximately 1 g/mL). If the result differs from the labeled volume by more than 10%, recalculate your concentration accordingly.
What Most Pages Get Wrong About Selank Nasal Spray
This is the section commodity blogs skip entirely.
1. They ignore dead volume. Most nasal atomizers have 0.05 to 0.2 mL of dead volume in the dip tube and valve assembly. If you fill an atomizer with exactly 1 mL of solution, you will not deliver 10 full 0.1 mL doses; the last 1 to 2 actuations will be sub-dose or air. Overfill slightly or account for this in your calculation.
2. They use nominal concentration without confirming the source peptide purity. A vial labeled "5 mg Selank" from a research chemical vendor may contain 80% to 98% peptide by weight depending on the supplier's synthesis quality. A 5 mg vial at 85% purity actually contains roughly 4.25 mg active peptide. This can shift your effective dose by 15% or more.
3. They assume refrigeration equals stability. Peptides in solution undergo hydrolysis and oxidation even at 4 degrees Celsius. The rate depends on pH, ionic strength, and specific residue chemistry. Selank contains no cysteine residues that would create disulfide scrambling issues, but the Thr and Arg residues can participate in slower degradation reactions. Formal stability data for Selank in bacteriostatic water do not appear to be publicly published; the 4-week convention used by researchers is based on analogy to similar peptide preparations, not Selank-specific stability studies.
4. They do not mention benzyl alcohol concentration limits. At 0.9%, benzyl alcohol is preservative-effective and is used in many approved nasal and injectable products. It is not zero-risk: high repeated nasal doses of benzyl alcohol have been associated with mucosal irritation. The concentration in bacteriostatic water is within the range of approved products, but it is not inert.
5. They conflate the Russian commercial product with DIY powder reconstitution. The approved 0.15% Selank nasal spray manufactured in Russia (brand Selanc by Pharmsyntez) is formulated under GMP, tested for sterility, endotoxin load, and potency. A home reconstitution is not equivalent to this product even if the peptide sequence is identical.
Stability, Storage, and When to Discard
| Condition | Recommendation | Reason |
|---|---|---|
| Lyophilized (dry) powder, sealed | Store at minus 20 degrees Celsius; room temperature acceptable for short shipping | Dry state dramatically slows hydrolysis; moisture is the primary degradation driver |
| Reconstituted in bacteriostatic water | Refrigerate at 2 to 8 degrees Celsius; use within 4 weeks | Lower temperature slows hydrolysis kinetics; preservative inhibits microbial growth |
| Room temperature (25 degrees Celsius) reconstituted | Use within 24 to 48 hours if unavoidable | Hydrolysis rates roughly double with every 10-degree Celsius increase (Arrhenius approximation); data for Selank specifically not published |
| Freeze-thaw cycles | Avoid repeated cycling | Ice crystal formation can mechanically disrupt peptide conformation; aliquot before freezing if long storage needed |
Discard if: the solution is no longer clear and colorless, visible particulates appear, or there is an unusual odor. These are nonspecific signs of degradation or contamination; a degraded peptide may still appear clear, so the 4-week guideline applies regardless of appearance.
Honest Head-to-Head: Nasal Spray vs. Subcutaneous Injection
| Parameter | Intranasal Selank | Subcutaneous Injection |
|---|---|---|
| Bioavailability | Lower and more variable; nasal peptide absorption typically ranges from roughly 10% to 40% for small peptides depending on formulation | Generally high (80 to 100% for subcutaneous peptides); more predictable |
| Onset | Rapid; nasal mucosa is highly vascularized | Rapid (minutes to tens of minutes) |
| CNS targeting | Olfactory route may provide direct CNS access bypassing BBB; class evidence, not Selank-specific | Relies on peripheral distribution and BBB transport |
| Convenience | No needles; easier to self-administer | Requires sterile injection technique |
| Infection risk (home preparation) | Lower than injection; nasal mucosa is not sterile | Higher; systemic infection possible from non-sterile injection |
| Established clinical precedent for Selank | Yes; Russian trials and approved product used this route | No published Selank clinical trials via SubQ |
| Dosing reproducibility (DIY) | Lower; atomizer variability, mucosal clearance variability | Higher with accurate syringe and insulin needle |
| Where nasal spray LOSES | Dose precision and bioavailability predictability | Wins on these parameters |
Label and COA Literacy: Judging Your Source
A certificate of analysis (COA) from a research peptide vendor should include at minimum:
- Identity confirmation: HPLC retention time or mass spectrometry (MS) confirming the correct molecular weight for Selank (MW approximately 751 Da).
- Purity percentage: Stated as area-under-the-curve (AUC) by HPLC. Below 95% is a meaningful quality concern for research use.
- Batch number and synthesis date: Allows you to assess how long the powder has been stored before reaching you.
- Endotoxin testing (LAL test): Especially important if subcutaneous use is intended. For intranasal use it matters less but still reflects overall quality control.
Red flags: a COA with no spectrometric data (only a stated percentage with no instrument trace), an unlabeled peak above 5% area in the HPLC trace, or no batch-specific data (a generic certificate printed for all products). Ask the vendor for a batch-specific COA, not a product-level certificate.
Reconstitution check: A properly synthesized lyophilized heptapeptide dissolves readily in bacteriostatic water at room temperature with gentle swirling. Difficulty dissolving, persistent cloudiness after 5 minutes of gentle mixing, or a pellet that does not break up suggests either degradation, contamination, or a non-peptide filler.
FAQ
How do you make Selank nasal spray from lyophilized powder?
Dissolve the lyophilized Selank vial in bacteriostatic water or sterile saline to your target concentration, transfer the solution into a sterile nasal atomizer bottle, and refrigerate. A common starting concentration is 300 mcg per 0.1 mL spray.
What diluent is best for Selank nasal spray?
Bacteriostatic water (0.9% benzyl alcohol) extends shelf life by inhibiting microbial growth. Sterile saline (0.9% NaCl) is also used but lacks a preservative and should be used within 24 to 48 hours once opened. Plain tap or distilled water is not appropriate.
What concentration should I make Selank nasal spray?
Research protocols typically range from 250 to 500 mcg per 0.1 mL actuation. A practical preparation is 3 mg total Selank dissolved in 1 mL diluent, delivering 300 mcg per 0.1 mL spray. Always verify your atomizer's actual spray volume before dosing.
What nasal atomizer should I use for Selank?
Use an atomizer calibrated to 0.1 mL per actuation with a particle size below 100 microns for nasal mucosal deposition. Devices such as the Aptar Unitdose or similar low-dead-volume nasal atomizers are preferred over repurposed spray bottles.
How long does homemade Selank nasal spray stay stable?
Reconstituted Selank in bacteriostatic water stored at 2 to 8 degrees Celsius is generally considered usable for up to 4 weeks by researchers, though formal stability data for home preparations are not publicly available. Discard if the solution is cloudy, discolored, or has particulates.
Can I use Selank nasal spray instead of subcutaneous injection?
Intranasal delivery avoids injection and can reach central nervous system targets via the olfactory route. However, intranasal bioavailability for peptides is typically lower and more variable than subcutaneous injection. Clinical studies on Selank used intranasal delivery, so there is at least precedent for the route.
Is making Selank nasal spray at home sterile enough?
Home preparation cannot replicate pharmaceutical-grade sterility. Use only sterile single-use syringes, sterile-filtered diluent, and a clean work surface. A laminar flow hood is ideal but rarely available. The nasal mucosa is not sterile, which reduces but does not eliminate infection risk compared with injection.
What are the risks of making Selank nasal spray incorrectly?
Risks include microbial contamination leading to nasal or sinus infection, incorrect dosing from miscalculation or wrong atomizer volume, peptide degradation from improper storage, and using an impure research compound. Nasal mucosal irritation from incorrect buffer pH is also possible.
Does Selank nasal spray actually work for anxiety?
Small Russian clinical trials conducted in the 1990s and 2000s reported anxiolytic effects with intranasal Selank at doses around 250 to 400 mcg per nostril. Sample sizes were small, blinding quality is uncertain, and independent replication in Western trials has not occurred. Evidence is Low by GRADE standards.
How do I calculate the right amount of diluent to add to Selank?
Divide the total peptide mass by your target concentration. Example: 5 mg Selank divided by 3 mg/mL target equals 1.67 mL diluent. Then check: each 0.1 mL spray delivers 0.3 mg (300 mcg). Always double-check with a second calculation before loading the atomizer.
Can I add anything to Selank nasal spray to improve absorption?
Some researchers add low concentrations of cyclodextrin or chitosan as permeation enhancers. These are not standard for DIY preparations and their safety in homemade peptide sprays is unvalidated. Avoid DMSO intranasally; it is a strong penetration enhancer with mucotoxic potential.
Where can I get pharmaceutical-grade Selank nasal spray?
Licensed Selank nasal spray (0.15%) is approved and manufactured in Russia under the brand Selanc. It is not FDA-approved in the United States. In the US, compounding pharmacies with 503A status may prepare Selank on a prescription basis, offering a more controlled alternative to DIY preparation.
Sources
- Semenova TP, Kozlovskaya MM, Zakharova NM, et al. Selank and tuftsin modulate the behavior of rats with different levels of anxiety in a chronic emotional stress model. Eksperimental'naia i Klinicheskaia Farmakologiia. 2009;72(4):6-10. (Russian-language primary trial; cited for clinical precedent.)
- Volkova A, Shadrina M, Kolomin T, et al. Analysis of the temporary effects on the expression of neurotrophins and their receptors in the hippocampus, frontal cortex, and cerebellum of rats receiving Selank. Bulletin of Experimental Biology and Medicine. 2012;153(6):741-743. PMC accessible.
- Zozulya AA, Neznamov GG, Siuniakov TS, 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;108(4):38-48. (Russian-language clinical report.)
- Illarioshkin SN, Klushnik TP, Danilov AB. Neuropeptide approach in therapy of anxiety disorders: Selank's place in the Russian clinical practice. Review article referenced in neurological conference proceedings.
- Ugur M, Bhatt DL, Bhatt S. Intranasal drug delivery and the nose-to-brain pathway: pharmacokinetics, mechanisms, and clinical relevance. Drug Delivery. Review literature; general class evidence for olfactory route.
- United States Pharmacopeia. USP Chapter 51: Antimicrobial Effectiveness Testing. USP-NF 2024. (Standard for preserved solutions including bacteriostatic water.)
- United States Pharmacopeia. USP Chapter 1, Injections and Implanted Drug Products. Guidance on benzyl alcohol as a preservative at 0.9%.
- Aptar Pharma. Nasal drug delivery systems product specifications. Aptar.com (device calibration data; accessed 2025).
- Guyatt GH, Oxman AD, Vist GE, et al. GRADE: an emerging consensus on rating quality of evidence and strength of recommendations. BMJ. 2008;336(7650):924-926. (GRADE framework applied throughout this article.)
- Pharmsyntez JSC. Selanc (Selank 0.15% nasal spray) product registration. Russian State Register of Medicines. (Documents existence of approved Russian product and concentration.)