Educational Reference · Research-Use-Only
Selank: Mechanism, Research, and Regulatory Status
A research-grade overview of Selank — what it is, how it works at the molecular level, what published studies have shown, and answers to the questions researchers ask most.
Last reviewed 2026-07-28
What is Selank?
Selank is a synthetic heptapeptide analogue of the endogenous immunomodulatory tetrapeptide tuftsin, extended at the C-terminus with Pro-Gly-Pro. Two mechanistic lines dominate the literature. The first concerns the enkephalinergic system: Selank dose-dependently inhibits enzymatic hydrolysis of plasma enkephalin with a reported half-maximal inhibitory concentration of 15 micromolar, proving more potent in the same assay than the peptidase inhibitors bacitracin and puromycin, and the authors proposed that stabilization of endogenous enkephalins underlies its observed profile.
The second concerns GABAergic modulation: radioligand-receptor analysis indicated that Selank affects GABA binding as a positive allosteric modulator in a subtype-selective, concentration-dependent manner, and that its joint action with benzodiazepines is non-cumulative and differs from either agent alone, suggesting binding sites that are distinct but possibly partially overlapping. Expression studies in rat frontal cortex found that Selank altered the expression of a large fraction of an 84-gene neurotransmission panel, with changes correlating positively with those produced by GABA itself. Notably, the corresponding in vitro experiment in IMR-32 neuroblastoma cells found no direct effect of Selank on GABAergic gene transcript levels, while co-administration with GABA suppressed GABA-induced expression changes, a result the authors interpreted as consistent with modulation of GABA-receptor interaction rather than direct transcriptional action.
Selank has additionally been reported to influence Th1/Th2 cytokine balance and interleukin gene expression, consistent with its derivation from an immunopeptide. The mechanism should be regarded as incompletely characterized, and independent reviewers outside Russia have explicitly described the compound as poorly studied.
Research highlights
What published peer-reviewed research and preclinical studies have established about Selank:
- 01Selank inhibits enzymatic hydrolysis of plasma enkephalin with a reported IC50 of 15 micromolar, exceeding the potency of bacitracin and puromycin in the same assay (Zozulya 2001).
- 02Radioligand-receptor analysis indicates Selank acts as a subtype-selective positive allosteric modulator of GABA binding, with non-cumulative interaction when combined with benzodiazepines (Vyunova 2018).
- 03Administration to rats altered expression of 45 of 84 assayed neurotransmission-related genes in frontal cortex at one hour, falling to 22 genes at three hours (Volkova 2016).
- 04In IMR-32 neuroblastoma cells Selank alone produced no change in GABAergic gene transcript levels, indicating its in vivo effect is unlikely to be direct transcriptional action on those genes (Filatova 2017).
- 05An independent US pharmacology review characterizes Selank as a poorly studied Russian drug with a GABAergic mechanism, noting it is sold to US consumers as a dietary supplement despite lacking approved drug status (Doyno and White 2021).
- 06No Selank study is registered on ClinicalTrials.gov; the available human literature is unregistered, Russian-language, and generally lacks described blinding or placebo control.
Frequently asked questions about Selank
What is Selank?+
Selank, also designated TP-7, is a synthetic heptapeptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro — the endogenous immunopeptide tuftsin extended with a C-terminal Pro-Gly-Pro tripeptide. It is supplied as a lyophilized powder for laboratory research use only and is not FDA-approved for any human use.
What is the proposed mechanism?+
Two lines predominate: inhibition of enkephalin-degrading enzymes, which would prolong the action of endogenous enkephalins, and subtype-selective positive allosteric modulation of GABA binding. Cell-culture work indicates the GABAergic effect is not mediated by direct changes in GABAergic gene transcription. Immunomodulatory effects on cytokine expression are also reported, consistent with its tuftsin derivation.
How does Selank differ from a benzodiazepine in research models?+
Reported receptor-binding work suggests Selank's site of action, while possibly partially overlapping, is not identical to the benzodiazepine site: joint application with diazepam produces effects that are non-cumulative and differ from either compound alone. Selank is a peptide with a distinct pharmacokinetic profile and should not be modelled as a benzodiazepine equivalent.
How does Selank differ from Semax?+
They share only the C-terminal Pro-Gly-Pro motif. Selank derives from tuftsin and is investigated in GABAergic, enkephalinergic and immunological models; Semax derives from ACTH(4-7) and is investigated in neurotrophin and cerebral-ischemia gene expression models. They are pharmacologically distinct.
How robust is the published evidence?+
Weak by international standards. Human studies are unregistered, Russian-language, and generally lack blinding and placebo control, and no study appears on ClinicalTrials.gov. A 2021 peer-reviewed US pharmacology review explicitly describes Selank as poorly studied. Results should be treated as preliminary.
References & sources
Every citation below was resolved against its primary source before publication — each PMID against the PubMed record and each DOI through doi.org. Follow any link to read the paper at the publisher rather than taking our summary on trust.
- [1]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. Bulletin of Experimental Biology and Medicine. 2001. PMID: 11740595 DOI: 10.1023/a:1013014607897
- [2]Vyunova TV, Andreeva LA, Shevchenko KV, Myasoedov NF. Peptide-based anxiolytics: the molecular aspects of Heptapeptide Selank biological activity. Protein and Peptide Letters. 2018. PMID: 30182833 DOI: 10.2174/0929866525666180904111160
- [3]Volkova A, Shadrina M, Kolomin T, et al.. Selank administration affects the expression of some genes involved in GABAergic neurotransmission. Frontiers in Pharmacology. 2016. PMID: 26973525 DOI: 10.3389/fphar.2016.00031
- [4]Filatova E, Kasian A, Kolomin T, et al.. GABA, selank, and olanzapine affect the expression of genes involved in GABAergic neurotransmission in IMR-32 cells. Frontiers in Pharmacology. 2017. PMID: 28352232 DOI: 10.3389/fphar.2017.00089
- [5]Doyno CR, White CM. Sedative-hypnotic agents that impact gamma-aminobutyric acid receptors: focus on flunitrazepam, gamma-hydroxybutyric acid, phenibut, and selank. Journal of Clinical Pharmacology. 2021. PMID: 34396551 DOI: 10.1002/jcph.1922
Where this data comes from
- —Citations & trial data: PubMed (NCBI, U.S. National Library of Medicine), Crossref and ClinicalTrials.gov.
- —Chemical identity: PubChem and UniProt. Where sources conflicted, the disputed value is omitted rather than guessed.
- —Regulatory status: U.S. FDA publications and, where applicable, the WADA Prohibited List. Compounding status changes frequently — verify against FDA directly before relying on it.
- —Purity, form and storage are handling and supplier conventions, not literature-derived values. Confirm against the lot-specific certificate of analysis.
Content last reviewed 2026-07-28. Compiled by Veridian Research from the primary literature. This page is an educational reference for laboratory researchers — it is not medical advice, and it describes no human use.
Regulatory status
Selank is not approved by the U.S. Food and Drug Administration for any indication and is not authorized for human use in the United States. FDA has placed Selank acetate (TP-7) in Category 2 of the bulk drug substances nominated under sections 503A/503B of the FD&C Act — substances that may present significant safety risks — noting that compounded drugs containing selank acetate may pose immunogenicity risk for certain routes of administration due to potential aggregation and peptide-related impurities, and that FDA lacks important information regarding safety issues raised by selank acetate administered to humans. Selank is separately reported to be a registered medicine in the Russian Federation, and a 2021 peer-reviewed US review notes it is sold to US consumers as a dietary supplement notwithstanding its unapproved drug status. Supplied strictly for in vitro and non-human laboratory research; not for human or veterinary use.
Research-Use-Only Material
Specifications and certificate of analysis
Selank is stocked as a research reagent. Analytical documentation — identity, purity and the lot-specific certificate of analysis — is published on the product record.
View specifications & COA →