Selank

A Russian anxiolytic nasal drop built from an immune peptide, with a plausible mechanism, a small set of unblinded Russian trials against a benzodiazepine, and no study a non-Russian reader can fully examine.

Summary

• Selank is a synthetic heptapeptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro: the immune tetrapeptide tuftsin with a Pro-Gly-Pro tail added for stability. It was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences, the same institute as semax.1

• It is registered in Russia as 0.15 percent nasal drops for anxiety. It is approved nowhere else.2

• Its proposed mechanisms are inhibition of the enzymes that break down enkephalins, the body's own opioid peptides, and altered expression of genes involved in GABA signalling.13

• The human trials are Russian, published in Russian with English abstracts, open-label, and compare selank with or add it to phenazepam, a Russian benzodiazepine. The largest enrolled 70 people.45

• No placebo-controlled trial in English exists. No trial is registered on ClinicalTrials.gov.

• Proline-containing peptides of this family, including selank, have anticoagulant effects in animal work, a property the FDA flagged for semax and which applies here.6

• The FDA placed selank acetate in Category 2 of its compounding policy in 2023, stating it "lacks important information regarding any safety issues raised by selank acetate administered to humans." It was not among the peptides considered by the advisory committee in July 2026.2

• A targeted PubMed search returns 68 records, nearly all from Russian institutions.

The Most Common Error About This Compound

Reading "anxiolytic without sedation or dependence" as a demonstrated property rather than a design goal. The Russian trials report that selank reduced anxiety with fewer side effects than phenazepam and no withdrawal.4 They were not blinded, they had no placebo arm, and comparing anything favourably with a benzodiazepine on sedation and dependence is not a high bar. The claim may be right. The evidence that would show it has not been produced.

Identity

What Is Selank?

Tuftsin is a natural tetrapeptide, Thr-Lys-Pro-Arg, released from immunoglobulin G in the spleen, which stimulates phagocytosis and has been studied for decades as an immunomodulator.7 Selank adds Pro-Gly-Pro to its C-terminus, the same stabilising tail used in semax, producing a heptapeptide that resists enzymatic breakdown and, in the developers' account, acquires anxiolytic and nootropic effects the parent lacks. Its Russian code is TP-7.

How Might It Work?

Two mechanisms are proposed, from the developers' laboratory. Selank and semax both inhibit the enzymes in human serum that degrade enkephalins, with an IC50 of 20 micromolar for selank, which would raise the body's own opioid peptides.1 And in cell and animal work, selank altered the expression of genes involved in GABAergic neurotransmission, which is the pathway benzodiazepines act on.38 In rats, selank enhanced diazepam's anxiolytic effect under chronic stress and attenuated morphine withdrawal.9

Both mechanisms are coherent with an anxiolytic. Both are also mechanisms with implications a product page does not mention: the first is opioid-adjacent, and the second is the benzodiazepine pathway.

Evidence Base

What Human Trials Exist?

What these share: Russian authorship including the developers, publication in Russian with English abstracts, no placebo arm, no described blinding, and outcome measures that the abstracts summarise rather than report. The 2015 study is labelled a randomised controlled trial and its abstract describes a comparison between two active treatments. ONPEPS has not been able to examine the full methods and reports what the abstracts say.

That is a thinner human record than semax's, which at least had healthy-volunteer imaging studies in English. For selank there is nothing in English beyond the mechanism papers.

What Is It Sold For?

Anxiety, mood, focus, "calm without sedation," and as the second half of a semax-and-selank pair. The FDA, reviewing semax in July 2026, noted that semax is sold "in combination with a different peptide, selank."11 No study has tested the combination.

Safety

What Is Known?

The Russian trials report good tolerability and fewer side effects than phenazepam, in the abstracts.4 The Russian registration implies a safety review ONPEPS cannot examine. There is no human pharmacokinetic study by any route and no study of the injectable form some vendors sell.

The FDA's Category 2 entry is brief: compounded selank acetate "may pose risk for immunogenicity for certain routes of administration due to the potential for aggregation and peptide-related impurities," and the agency "lacks important information regarding any safety issues raised by selank acetate administered to humans."2

What Is Unknown

Three things worth naming. Bleeding: the developers' own laboratory has published on the anticoagulant effects of proline-containing regulatory peptides including selank, and the FDA raised the same concern for semax.611 Dependence: a compound acting on enkephalin degradation and GABA gene expression, sold for daily use against anxiety, has not been studied for tolerance or withdrawal in a design that could detect them. Immune effects: selank is a tuftsin analogue and alters cytokine balance, and nobody has asked what chronic immunomodulation by a nasal spray does over years.10

Regulatory Status

Where Is It Approved?

Russia, as 0.15 percent nasal drops. Nowhere else. It is not named on the WADA Prohibited List; because it holds a governmental approval, the S0 catch-all does not obviously apply, and ONPEPS cannot state a definitive status.

Where Does It Stand on Compounding?

In September 2023 the FDA placed selank acetate, listed as "Selank acetate (TP-7)," in Category 2 of its interim compounding policy. As of April 2026 it appears among substances nominated but withdrawn, with the original safety text unchanged.2

Unlike semax, selank was not among the seven peptides the Pharmacy Compounding Advisory Committee considered in July 2026, so the vote that recommended semax for three neurological conditions has no bearing on it.12 It is not on the 503A bulks list, and no pharmacy in the United States has a lawful basis on which to compound it. A "semax/selank" product from a US source is therefore half a recommended-but-not-adopted peptide and half a peptide that has never been reviewed.

Related ONPEPS Coverage

• Selank sourcing and quality: the other half of the Moscow pair

• Selank cost and access: a Russian registration and nothing else

• Semax: the same institute, the same tail, a July 2026 vote

• DSIP: another peptide sold on an opioid-adjacent mechanism

• FDA peptide news July 2026: the votes, the dissent and what happens next

What Would Change This Page

A placebo-controlled, blinded trial of intranasal selank in anxiety, published in English with its methods, would be the first evidence a reader could weigh. A nomination to the FDA's advisory committee would at least produce a regulator's reading of the Russian record. Neither is under way.

References

1. Kost NV, Sokolov OIu, Gabaeva MV, Grivennikov IA, Andreeva LA, Miasoedov NF, et al. Semax and selank inhibit the enkephalin-degrading enzymes from human serum. Bioorg Khim. 2001;27(3):180-183. In Russian; English abstract. pubmed.ncbi.nlm.nih.gov/11443939

2. US Food and Drug Administration. Category 2 of the Bulk Substances Nominated Under Sections 503A or 503B of the Federal Food, Drug, and Cosmetic Act. Entry for selank acetate (TP-7). Content current as of 22 April 2026. fda.gov

3. 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. Open access. pubmed.ncbi.nlm.nih.gov/26924987

4. Medvedev VE, Tereshchenko ON, Israelian AIu, Chobanu IK, Kost NV, Sokolov OIu, et al. 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. In Russian; English abstract. pubmed.ncbi.nlm.nih.gov/25176261

5. Medvedev VE, Tereshchenko ON, Kost NV, Ter-Israelyan AY, Gushanskaya EV, Chobanu IK, et al. Optimization of the treatment of anxiety disorders with selank. Zh Nevrol Psikhiatr Im S S Korsakova. 2015;115(6):33-40. In Russian; English abstract. pubmed.ncbi.nlm.nih.gov/26356395

6. Liapina LA, Pastorova VE, Obergan TIu, Samonina GE, Ashmarin IP, Miasoedov NF. Comparison of anticoagulant effects of regulatory proline-containing oligopeptides: specificity of glyprolines, semax, and selank and potential of their practical application. Izv Akad Nauk Ser Biol. 2006;(2):193-203. In Russian; English abstract. pubmed.ncbi.nlm.nih.gov/16634437

7. Siebert A, Gensicka-Kowalewska M, Cholewinski G, Dzierzbicka K. Tuftsin: properties and analogs. Curr Med Chem. 2017;24(34):3711-3727. Paywalled. pubmed.ncbi.nlm.nih.gov/28745220

8. Filatova E, Kasian A, Kolomin T, Rybalkina E, Alieva A, Andreeva L, et al. GABA, selank, and olanzapine affect the expression of genes involved in GABAergic neurotransmission in IMR-32 cells. Front Pharmacol. 2017;8:89. Open access. pubmed.ncbi.nlm.nih.gov/28293190

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. Open access. pubmed.ncbi.nlm.nih.gov/28280289

10. Uchakina ON, Uchakin PN, Miasoedov NF, Andreeva LA, Shcherbenko VE, Mezentseva MV, et al. Immunomodulatory effects of selank in patients with anxiety-asthenic disorders. Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108(5):71-75. In Russian; English abstract. pubmed.ncbi.nlm.nih.gov/18577961

11. US Food and Drug Administration. Semax-related bulk drug substances: FDA presentation to the Pharmacy Compounding Advisory Committee, 24 July 2026. Docket FDA-2025-N-6895. Cited for the semax/selank combination products and the bleeding concern. fda.gov

12. US Food and Drug Administration. July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory Committee. Agenda listing the seven substances considered; selank is not among them. Docket FDA-2025-N-6895. fda.gov

Not Medical Advice

Selank is a registered medicine in Russia and an unapproved substance everywhere else. Nothing here substitutes for its Russian label or for a prescriber. Given the anticoagulant property reported for this peptide family, anyone on blood-thinning medication should raise it with a clinician before use. Consult a qualified healthcare provider before acting on anything here.

Evidence counts on the library index retrieved 23 July 2026. Literature and regulatory sources verified 16 September 2026. Re-verify before relying on any regulatory statement here.