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PeptideLimited humanNot FDA approved

Selank

Selank

Last reviewed October 27, 2026 · 20 sources · Written for general readers · Compare with another compound →

The bottom line

Selank is a Russian made peptide studied mainly for anxiety. A few small Russian trials found it eased anxiety about as well as older sedative drugs, but none compared it with a placebo, and claims about focus, mood and immunity rest on even thinner data. It is not approved in the United States, and FDA says key safety information is missing.

Where the evidence stands

What it is

Selank is a lab made chain of seven amino acids, Thr-Lys-Pro-Arg-Pro-Gly-Pro.[1] PubChem lists its formula as C33H57N11O9.[2] FDA's substance registry lists its CAS number as 129954-34-3.[3]

Russian researchers study it mostly as an anxiety treatment.[4] In the United States it is not an approved drug, yet it has been sold to consumers labeled as a dietary supplement.[5]

Name
Selank (Selank)
Other names
selank acetate, TP-7, Thr-Lys-Pro-Arg-Pro-Gly-Pro
Type
Peptide
Sequence
TKPRPGP
CAS number
129954-34-3
Formula
C33H57N11O9
Molecular weight
About 751.9 g/mol

How it works

How selank works is not settled. Lab and animal studies point to a few ideas.[1]

  • In test tube studies, it changed how the calming brain chemical GABA binds to its receptors, which may overlap with how some anxiety drugs act.[1]
  • It slowed the breakdown of enkephalins, the body's own calming and pain relieving chemicals, in human blood samples.[6]
  • In rat brain slices, it increased calming (inhibitory) signals between nerve cells in the hippocampus.[7]
  • In mice, a drug that blocks opioid receptors cancelled one of selank's behavior effects, which points to the body's own opioid system.[8]
  • In rats, it changed the activity of dozens of genes tied to GABA signals within an hour.[4]

These are lab and animal findings, and the exact mechanism is still a hypothesis.

What the research shows

We keep animal and human evidence apart. A result in animals is a reason to study something in people, not proof that it works in people.

Animal and lab studies

Calming and learning effects in rodents

  • In rats under long term mild stress, selank reduced anxious behavior in a maze test, and it worked best when combined with diazepam.[9]
  • In rats whose brain chemical systems were damaged just after birth, selank restored learning, memory and attention that the damage had impaired.[10]
  • In mice, selank prevented the hyperactive behavior that alcohol causes.[11]
  • In mouse spleens, a single injection changed the activity of 34 of 84 immune and inflammation genes within a day.[12]
  • Rat gene studies show it shifts GABA related genes in the front of the brain, in ways that partly resemble GABA itself.[4]

Limit: Animal anxiety and memory tests do not reliably predict results in people, and nearly all of this work comes from one research network.

Human studies

A few small Russian trials, none against placebo

  • A randomized Russian trial of 62 people with generalized anxiety disorder or neurasthenia (a fatigue and stress condition) gave 30 selank and 32 medazepam, an older benzodiazepine drug. Anxiety eased about equally in both groups, and selank also eased fatigue and had a mild stimulating effect.[13]
  • In the same trial, patients had low blood levels of a marker tied to enkephalin activity, and the marker rose during selank treatment.[13]
  • A 2014 study of 60 patients with anxiety and body symptom disorders compared selank with phenazepam, another benzodiazepine. Selank eased anxiety, had a mild effect on thinking, and the calm lasted about a week after the last dose. Random assignment and blinding were not stated.[14]
  • A 2015 randomized study of 70 anxiety patients gave 40 selank plus phenazepam and 30 phenazepam alone. The combined group improved sooner, and had fewer phenazepam side effects such as sleepiness, memory trouble, weakness and sexual problems. Blinding was not described.[15]
  • A small Russian study measured immune signals in the blood of anxious patients over 14 days of selank and found shifts in the balance of immune messengers. It did not test whether people got fewer infections, and its size was not given in the summary.[16]
  • A brain scan study of 52 healthy adults compared selank, semax and placebo. It found short term changes in how the amygdala, a fear and emotion center, linked with nearby brain areas. It did not measure anxiety or mood.[17]

Limit: We found no large, independent, placebo controlled trial. The trials are small, published in Russian by the developer's network, and compare selank with other drugs.

Claims check

The most common claims about this compound, and what studies actually found. Verdicts rate the evidence, not whether you should use it.

Eases anxiety

Mixed results

In a randomized trial of 62 anxious patients, selank eased anxiety about as much as medazepam.[13] A 60 patient study found similar relief compared with phenazepam.[14] Without a placebo group, it is hard to know how much of the relief came from the drug itself.

Calms without sedation or dependence

Not tested

Small trials reported mild stimulating rather than sedating effects, but they were not designed to test sedation or dependence.[13] We found no human study of tolerance, dependence or withdrawal. FDA says important human safety information is missing.[18]

Sharpens focus and memory

Mixed results

In rats with early brain damage, selank restored learning and memory.[10] In a 60 patient anxiety study, the authors reported a mild effect on thinking, and a 70 patient study found it reduced memory and attention problems caused by phenazepam.[14][15] No trial has tested it for focus in healthy people.

Reduces fatigue and lifts mood

Mixed results

In a 62 patient trial, selank eased fatigue and had a mild stimulating effect compared with medazepam.[13] Quality of life scores improved in two other small studies.[14][15] None used a placebo.

Boosts the immune system

Mixed results

A small Russian study found shifts in blood immune messengers after 14 days of selank in anxious patients.[16] In mice, it changed many immune genes in the spleen.[12] No study has shown that people taking it get fewer or milder infections.

Softens side effects of sedative drugs

Mixed results

In a randomized study of 70 patients, adding selank to phenazepam reduced sleepiness, memory trouble, weakness and sexual side effects compared with phenazepam alone.[15] Blinding was not described, and no other trial has checked this.

Known risks and side effects

  • Unknown product quality. Selank sold online is not made under drug quality rules. FDA says impurities or clumped peptide could trigger immune reactions.[18]
  • Little human safety data. FDA says it lacks important information about safety problems selank may cause in people.[18] The published trial summaries rarely list side effects or how often they happened.[14]
  • Mixing with sedatives. Selank appears to act on the same GABA system as sedatives. Experts warn that high doses or mixing GABA acting drugs has caused dangerous breathing problems.[5]
  • Sport rules. WADA does not name selank, but its 2026 list bans any drug with no government approval for human use.[19]

Regulatory status

Today: Selank is not FDA approved. Its nomination for pharmacy compounding was withdrawn, and it was not on the July 2026 advisory committee agenda.[18][20]

  1. The 2026 WADA list took effect. It does not name selank, but its S0 rule bans any drug with no government approval for human use.[19]
  2. FDA listed selank acetate among substances once held in Category 2, its list of compounding safety risks, whose nominations were withdrawn.[18]
  3. FDA advisers reviewed seven peptides for compounding. Selank was not one of them.[20]

Sources

  1. Vyunova TV, Andreeva L, Shevchenko K, Myasoedov N. Peptide-based Anxiolytics: The Molecular Aspects of Heptapeptide Selank Biological Activity. Protein Pept Lett. 2018;25(10):914-923. PMID 30255741
  2. National Center for Biotechnology Information. PubChem Compound Summary for CID 11765600, Selank. PubChem CID 11765600
  3. U.S. FDA and NCATS Global Substance Registration System (GSRS). Selank, UNII TS9JR8EP1G. Codes: CAS 129954-34-3; PubChem CID 11765600. FDA GSRS
  4. Volkova A, Shadrina M, Kolomin T, Andreeva L, Limborska S, Myasoedov N, Slominsky P. Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission. Front Pharmacol. 2016;7:31. PMID 26924987
  5. Doyno CR, White CM. Sedative-Hypnotic Agents That Impact Gamma-Aminobutyric Acid Receptors: Focus on Flunitrazepam, Gamma-Hydroxybutyric Acid, Phenibut, and Selank. J Clin Pharmacol. 2021;61 Suppl 2:S114-S128. PMID 34396551
  6. Zozulya AA, Kost NV, Sokolov OYu, Gabaeva MV, Grivennikov IA, Andreeva LN, Zolotarev YA, Ivanov SV, Andryushchenko AV, Myasoedov NF, Smulevich AB. The inhibitory effect of Selank on enkephalin-degrading enzymes as a possible mechanism of its anxiolytic activity. Bull Exp Biol Med. 2001;131(4):315-317. PMID 11550013
  7. Povarov IS, Kondratenko RV, Derevyagin VI, Myasoedov NF, Skrebitsky VG. Effect of Selank on Spontaneous Synaptic Activity of Rat Hippocampal CA1 Neurons. Bull Exp Biol Med. 2017;162(5):640-642. PMID 28361410
  8. Meshavkin VK, Kost NV, Sokolov OYu, Zolotarev YuA, Myasoedov NF, Zozulya AA. Naloxone-blocked depriming effect of anxiolytic selank on apomorphine-induced behavioral manifestations of hyperfunction of dopamine system. Bull Exp Biol Med. 2006;142(5):598-600. PMID 17415472
  9. Kasian A, Kolomin T, Andreeva L, Bondarenko E, Myasoedov N, Slominsky P, Shadrina M. Peptide Selank Enhances the Effect of Diazepam in Reducing Anxiety in Unpredictable Chronic Mild Stress Conditions in Rats. Behav Neurol. 2017;2017:5091027. PMID 28280289
  10. Semenova TP, Kozlovskaya MM, Zakharova NM, Kozlovskii II, Zuikov AV. Effect of selank on cognitive processes after damage inflicted to the cerebral catecholamine system during early ontogeny. Bull Exp Biol Med. 2007;144(5):689-691. PMID 18683497
  11. Kolik LG, Nadorova AV, Seredenin SB. Selank Inhibits Ethanol-Induced Hyperlocomotion and Manifestation of Behavioral Sensitization in DBA/2 Mice. Bull Exp Biol Med. 2016;162(1):56-59. PMID 27878720
  12. Kolomin T, Shadrina M, Andreeva L, Slominsky P, Limborska S, Myasoedov N. Expression of inflammation-related genes in mouse spleen under tuftsin analog Selank. Regul Pept. 2011;170(1-3):18-23. PMID 21609736
  13. Zozulia 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]. Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108(4):38-48. PMID 18454096
  14. Medvedev VE, Tereshchenko ON, Israelian AIu, Chobanu IK, Kost NV, Sokolov OIu, Miasoedov NF. [A comparison of the anxiolytic effect and tolerability of selank and phenazepam in the treatment of anxiety disorders]. Zh Nevrol Psikhiatr Im S S Korsakova. 2014;114(7):17-22. PMID 25176261
  15. Medvedev VE, Tereshchenko ON, Kost NV, Ter-Israelyan AYu, Gushanskaya EV, Chobanu IK, Sokolov OYu, Myasoedov NF. [Optimization of the treatment of anxiety disorders with selank]. Zh Nevrol Psikhiatr Im S S Korsakova. 2015;115(6):33-40. PMID 26356395
  16. Uchakina ON, Uchakin PN, Miasoedov NF, Andreeva LA, Shcherbenko VE, Mezentseva MV, Gabaeva MV, Sokolov OIu, Zozulia AA, Ershov FI. [Immunomodulatory effects of selank in patients with anxiety-asthenic disorders]. Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108(5):71-75. PMID 18577961
  17. Panikratova YR, Lebedeva IS, Sokolov OYu, Rumshiskaya AD, Kupriyanov DA, Kost NV, Myasoedov NF. Functional Connectomic Approach to Studying Selank and Semax Effects. Dokl Biol Sci. 2020;490(1):9-11. PMID 32342318
  18. U.S. Food and Drug Administration. Certain bulk drug substances for use in compounding that may present significant safety risks. Content current as of April 22, 2026. FDA
  19. World Anti-Doping Agency. World Anti-Doping Code International Standard: Prohibited List 2026. In force January 1, 2026. WADA 2026 List
  20. U.S. Food and Drug Administration. Agenda, Pharmacy Compounding Advisory Committee meeting, July 23 to 24, 2026. FDA agenda
Medical disclaimer

This page is educational information only. It is not medical advice and does not replace care from a licensed medical provider. Do not use this page to decide whether to take any substance. Talk to a licensed medical provider first.

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