Selank is a synthetic seven-amino-acid peptide developed in Russia and studied mainly for anxiety. It is registered as a medicine in Russia but not approved by the FDA, and almost all of its research comes from a few Moscow institutes.
Not FDA-approved
Limited human data
Also known as Thr-Lys-Pro-Arg-Pro-Gly-Pro, TKPRPGP, Tuftsin analogue
Written by Upzo editorial team
Legal status
Not FDA-approved for any use.
Checked on Oct 26, 2026
Example vials
5 mg · 10 mg
5 mg + 2 mL
2,500 mcg/mL
Per U-100 unit
25 mcg
Studies in library
8
01
What is Selank?
Selank is a chain of seven amino acids, Thr-Lys-Pro-Arg-Pro-Gly-Pro (Zozulya 2001). The first four are tuftsin, a natural fragment of an immune protein; the last three (Pro-Gly-Pro) are an added tail. It is described in the Russian literature as an anxiolytic (anti-anxiety) drug.
It was developed in Moscow, and its research is concentrated in a small number of Russian institutes, in particular the Institute of Molecular Genetics of the Russian Academy of Sciences, where many of the authors are based. Most clinical papers are in Russian, with English abstracts. In Russia it is registered as a 0.15% nasal drop sold without prescription, according to the Russian Vidal drug reference. We could not find approval by the FDA, the European Medicines Agency or any other Western regulator, or any trial registered and run outside Russia.
Independent analysts have noted that Selank, sold online as a "research peptide" in nasal sprays and injectable powders, has not completed clinical trials of the kind Western regulators require (Vanhee 2020).
Type: synthetic peptide, 7 amino acids (tuftsin plus Pro-Gly-Pro).
Studied for: generalised anxiety and related anxiety disorders, mainly in Russia.
Strongest evidence: a few small Russian clinical comparisons with benzodiazepines, published in Russian, with unclear randomisation and blinding.
Legal status: registered as a medicine in Russia; not approved in the US.
02
Selank protocols and supplies
Schedules reported for this peptide, with the syringe measure for each step and the supplies each one takes. Reported use is not evidence that a schedule works or is safe, and none of this is medical advice.
Intranasal, 3 times a day
Intranasal spray, 3 times a day
Community-reported
Reported in the research community. It has not been tested as a schedule in human trials. Worked out with a 10 mg vial made up to 10 mL of sterile saline (1 mg/mL, 100 mcg per 0.10 mL spray).
Amounts as reported, with the syringe or spray measure for the vial below. Not a recommendation.
Period
Amount each time
Sprays (0.10 mL)
Volume
Days 1-14
300 mcg
3
0.3 mL
Minimum supplies, worked out from the amounts above. Add a margin for losses.
Item
14 days
Doses
42
Total peptide
12.6 mg
Selank vials (10 mg)
2
Sterile saline
20 mL
Nasal spray bottles (one per vial)
2
03
Selank doses used in studies
The dose each published study gave its participants, copied from the paper. Not dosing instructions; animal doses do not convert directly to people.
At a glance: 8 studies report a dose (4 in people, 4 in animals).
Doses used in human studies
Uchakina ON 2008: 10^-7 M in blood cell cultures; dose in patients not given in the abstract; see the paper (In patients (route not given in the abstract) and added to blood cell cultures; 14 days in patients)
Every study
Doses as reported by each study. Not a recommendation.
Not applicable (laboratory analysis of products; no one was given the peptides)
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04
Evidence at a glance
What has been studied, by type of evidence. A result in animals or cells is a reason to study something in people, not proof that it works in people.
In humans
Summarised
The human studies we could verify in PubMed are all Russian, small, and published in a Russian-language journal. Their abstracts do not describe placebo groups or blinding:
Generalised anxiety and neurasthenia: 62 patients received Selank or medazepam, a benzodiazepine. Anti-anxiety effects were reported as similar, with additional anti-fatigue effects for Selank (Zozulia 2008).
Compared with phenazepam: in 60 patients with anxiety and related disorders, Selank was reported to reduce anxiety, with the effect lasting a week after the last dose (Medvedev 2014).
Added to phenazepam: in 70 patients, adding Selank to phenazepam was reported to speed up improvement and reduce benzodiazepine side effects such as sedation and memory problems (Medvedev 2015).
Immune markers: in patients with anxiety disorders, 14 days of Selank was followed by changes in the balance of blood immune signalling molecules (cytokines) (Uchakina 2008).
Verdict: the human evidence is thin. The studies are small, come from a small circle of Moscow researchers (the same researcher, N. F. Myasoedov, co-authored all four), and do not report placebo control or blinding in their abstracts. No trial outside Russia has been published. Whether Selank reduces anxiety more than placebo has not been reliably shown.
In animals
Summarised
Anxiety and stress in rats
In rats under chronic unpredictable stress, Selank alone reduced anxiety-like behaviour in a maze test, and combining it with diazepam was the most effective option in stressed animals (Kasian 2017).
Brain gene activity
In the rat frontal cortex, Selank changed the activity of dozens of genes involved in nerve signalling within hours, in a pattern that overlapped with the effect of GABA, the brain's main calming messenger (Volkova 2016).
In cells (in vitro)
Summarised
In human blood plasma, Selank blocked enzymes that break down enkephalins, the body's own opioid-like peptides, more strongly than standard enzyme blockers (Zozulya 2001). Effects in a test tube show what a molecule can do, not what it does in a body.
Proposed mechanisms from cell and animal studies. A plausible mechanism is not evidence of an effect in people.
No mechanism has been established. The Russian studies propose several, each shown in a test tube or in animals:
Slowing enkephalin breakdown: it inhibited enkephalin-degrading enzymes in human plasma, which could prolong the action of natural opioid-like peptides (Zozulya 2001).
GABA system: it changed the expression of genes for GABA receptors and related proteins in rat brain, which the authors interpret as a possible indirect effect on the GABA system that benzodiazepines act on (Volkova 2016).
Immune signalling: it changed levels of cytokines such as IL-6 in blood cells and in patients (Uchakina 2008).
06
Reconstitution
How concentration changes with the amount of liquid added. A U-100 insulin syringe holds 1 mL in 100 units, so each unit is 0.01 mL. Step-by-step guide.
Step by step
Wash your hands and work on a clean, uncluttered surface. Let a refrigerated vial reach room temperature so the stopper is easier to pierce.
Wipe the rubber stopper of the peptide vial and of the bacteriostatic water with a fresh alcohol swab, and let them air-dry.
Draw the chosen volume of bacteriostatic water into a sterile syringe. With 2 mL, a 5 mg vial ends up at 2,500 mcg/mL, or 25 mcg per U-100 unit.
Insert the needle through the stopper and let the water run slowly down the inside wall of the vial, not straight onto the powder.
Swirl or roll the vial gently until the powder dissolves. Do not shake it: foaming can damage some peptides.
Check the solution against the light. It should be clear; cloudiness or particles mean something is wrong with the vial or the water.
Write the date and the volume of water on the label. Every unit calculation later depends on that volume.
Store the reconstituted Selank vial in the refrigerator, away from light.
Concentration by volume
Concentration after adding the liquid, and how much peptide each U-100 unit (0.01 mL) holds.
Vial
Liquid added
Concentration
Per unit
5 mg
1 mL
5,000 mcg/mL
50 mcg
5 mg
2 mL
2,500 mcg/mL
25 mcg
5 mg
3 mL
1,667 mcg/mL
16.7 mcg
10 mg
1 mL
10,000 mcg/mL
100 mcg
10 mg
2 mL
5,000 mcg/mL
50 mcg
10 mg
3 mL
3,333 mcg/mL
33.3 mcg
Reconstitution calculator
Arithmetic only. It assumes the vial holds exactly what the label says.
Concentration
2,500 mcg/mL
Per U-100 unit
25 mcg
Volume for your amount
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07
Measuring with a U-100 syringe
What each mark on an insulin syringe holds once the vial is mixed. This is arithmetic, not a dose.
Reading a U-100 syringe: how much peptide each mark holds in a 5 mg vial mixed with 2 mL. Not a dose.
Syringe mark
Volume
Peptide in that volume
5 units
0.05 mL
125 mcg
10 units
0.1 mL
250 mcg
20 units
0.2 mL
500 mcg
25 units
0.25 mL
625 mcg
50 units
0.5 mL
1.25 mg
100 units
1 mL
2.5 mg
A U-100 insulin syringe holds 1 mL in 100 units, so each unit is 0.01 mL. The marks measure volume, not peptide.
Syringes come in 0.3 mL (30 units), 0.5 mL (50 units) and 1 mL (100 units) sizes. The smaller ones have finer marks and are easier to read for small volumes.
Read the volume at the top edge of the plunger's rubber seal, at eye level.
Tap out air bubbles before reading: a bubble takes up volume and makes the reading wrong.
Use a new sterile syringe and needle every time, and dispose of them in a sharps container.
08
Supplies
What reconstituting and measuring a vial takes.
The peptide vial, with its certificate of analysis (COA) for that batch. See how to read a COA.
Bacteriostatic water (water with 0.9% benzyl alcohol), which keeps a multi-use vial from growing bacteria. Sterile water has no preservative.
Sterile syringes to add the water, and U-100 insulin syringes to measure.
Alcohol swabs for the stoppers.
A sharps container for used needles.
A label or marker to write the date and the volume of water on the vial.
09
Side effects, safety and legal status
Side effects and long-term safety are not well documented outside the Russian clinical literature. The published abstracts describe it as well tolerated, but the studies are small and short and were not designed to detect uncommon problems.
Product quality: Selank sold online as a research peptide is not checked by any regulator. A Belgian control laboratory identified Selank and Semax in seized preparations of unknown content and warned that such peptides are freely sold as injectable powders and nasal sprays (Vanhee 2020).
Use with sedatives: it has been studied together with benzodiazepines in Russian patients and rats (Medvedev 2015; Kasian 2017). How it interacts with other sedatives, alcohol or psychiatric medicines has not been studied to Western regulatory standards.
Injection risks: the approved Russian product is a nasal drop. Injectable powders sold online add the risk of infection if they are not sterile.
FDA
Not FDA-approved for any use.
Status checked on
Oct 26, 2026
10
Storing Selank
Before mixing
Freeze-dried (lyophilised) peptide is the most stable form. It is usually kept refrigerated, or frozen for long storage, sealed and away from light.
Heat, moisture and light speed up degradation. Keep the vial in its box and avoid leaving it in a car or by a window.
After mixing
Keep the reconstituted vial refrigerated and away from light. Do not freeze it again: freezing and thawing a solution can break the peptide down.
How long a mixed vial stays good depends on the peptide and the diluent, and for most research peptides there is no published stability data. Follow the supplier's guidance and discard any vial that turns cloudy.
Pierce the stopper as few times as possible, and always with a new sterile needle after wiping it with alcohol.
Write the volume of water on the label (for example "2 mL"). Without it, the unit calculations cannot be checked later.
11
Questions about Selank
Is Selank FDA-approved?
Not FDA-approved for any use.
What doses of Selank have been studied?
Our library has 8 studies on Selank. The doses each one used are in section 03, next to the study. They are not dosing instructions.
How much Selank is in each syringe unit?
It depends on how much liquid is added to the vial. For a 5 mg vial with 2 mL, each U-100 unit holds 25 mcg. The reconstitution table and calculator work it out for other volumes.
Is Selank approved anywhere?
It is registered as a medicine in Russia, as 0.15% nasal drops. We could not find approval by the FDA, the European Medicines Agency or other Western regulators.
Why is almost all Selank research Russian?
Selank was developed in Moscow, and most of the studies come from a few Russian institutes linked to its development, often published in Russian. No independent trial outside Russia has been published.
Is Selank a benzodiazepine?
No. It is a peptide with a different structure. Russian studies compared it with benzodiazepines such as phenazepam and medazepam and suggested it may act indirectly on the same GABA system, but this has not been confirmed in independent research.
How much bacteriostatic water goes into a 5 mg Selank vial?
There is no single correct volume: it only changes the concentration. For a 5 mg vial, 1 mL gives 5,000 mcg/mL, 2 mL gives 2,500 mcg/mL, 3 mL gives 1,667 mcg/mL. More water makes small amounts easier to measure; less water keeps volumes small. Whatever volume is used, write it on the label.
What does one unit on an insulin syringe mean?
On a U-100 syringe, 100 units = 1 mL, so one unit is 0.01 mL. How much peptide that holds depends on the concentration of the vial, which depends on how much water was added.
Can doses from animal studies of Selank be converted to people?
No. Animal doses are reported per kilogram for a different species, and scaling them to people is not reliable. That is why Upzo shows each study dose next to its study, unconverted.
How should Selank be stored?
Unopened freeze-dried vials are usually kept refrigerated and away from light. Once mixed, keep the vial refrigerated and follow the supplier's guidance on how long it lasts.
12
References
Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia. Zozulia AA, Neznamov GG, Siuniakov TS, et al. Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova. 2008;108:38-48. PMID 18454096
A comparison of the anxiolytic effect and tolerability of selank and phenazepam in the treatment of anxiety disorders. Medvedev VE, Tereshchenko ON, Israelian AIu, et al. Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova. 2014;114:17-22. PMID 25176261
Optimization of the treatment of anxiety disorders with selank. Medvedev VE, Tereshchenko ON, Kost NV, et al. Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova. 2015;115:33-40. doi:10.17116/jnevro20151156133-40
Immunomodulatory effects of selank in patients with anxiety-asthenic disorders. Uchakina ON, Uchakin PN, Miasoedov NF, et al. Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova. 2008;108:71-75. PMID 18577961
The inhibitory effect of Selank on enkephalin-degrading enzymes as a possible mechanism of its anxiolytic activity. Zozulya AA, Kost NV, Yu Sokolov O, et al. Bulletin of Experimental Biology and Medicine. 2001;131:315-317. doi:10.1023/a:1017979514274
Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission. Volkova A, Shadrina M, Kolomin T, et al. Frontiers in Pharmacology. 2016;7:31. doi:10.3389/fphar.2016.00031
Peptide Selank Enhances the Effect of Diazepam in Reducing Anxiety in Unpredictable Chronic Mild Stress Conditions in Rats. Kasian A, Kolomin T, Andreeva L, et al. Behavioural Neurology. 2017;2017:5091027. doi:10.1155/2017/5091027
The occurrence of putative cognitive enhancing research peptides in seized pharmaceutical preparations: An incentive for controlling agencies to prepare for future encounters of the kind. Vanhee C, Francotte A, Janvier S, et al. Drug Testing and Analysis. 2020;12:371-381. doi:10.1002/dta.2717
Research and education only. Not medical advice. Many peptides on this site are not approved by the FDA for human use. Doses shown are the ones used in published studies and are not a recommendation. Talk to a licensed clinician before using any of them. Read the full disclaimer.