What Is Selank? Definition and What Research Reports
Selank is a synthetic seven-amino-acid peptide built from a fragment of the immune peptide tuftsin with a stabilising tripeptide tail. It was developed in Russia and studied mainly as an anxiolytic, with published work in rodents and some Russian clinical reports on anxiety disorders. Laboratory studies described effects on GABA-related gene expression, hippocampal synaptic activity, BDNF levels and stress markers. It is not an FDA-approved drug in the United States and remains a research compound elsewhere.
Plain definition
Selank is a short synthetic peptide — a chain of seven amino acids — that was designed in Russia as a laboratory and clinical research compound, most often described in the literature as an anxiolytic (an anti-anxiety agent). It was built by taking a naturally occurring immune-system peptide fragment called tuftsin and attaching a short chemical "tail" so the molecule survives longer in the body. In published research it has been given to rats and, in a smaller Russian literature, to people with anxiety disorders, and investigators measured things like behaviour under stress, brain gene expression and blood markers. This page defines the term and summarises what those published papers reported; it does not describe use.
This page is for educational purposes only and is not medical advice; consult a licensed physician about any health decision. Selank is not an approved medicine in the United States and material sold under this name outside of registered clinical settings is typically labelled research-use-only.
What Selank is in biochemical terms
Selank is a heptapeptide. Its parent structure is tuftsin, a four-amino-acid fragment (Thr-Lys-Pro-Arg) released from the heavy chain of immunoglobulin G and long studied for its effects on macrophages and immune signalling. Selank extends that tuftsin sequence with a three-amino-acid stabilising tail, which is the standard medicinal-chemistry trick for slowing enzymatic breakdown of a very short peptide. Papers in the verified literature consistently describe Selank as "a peptide analog of tuftsin" — that phrasing appears directly in study titles examining morphine-withdrawal signs in rats (PMID 36322304) and ethanol-related memory impairment (PMID 31625062).
Because it derives from an immune peptide but was investigated for brain-related endpoints, Selank sits awkwardly across categories. Research groups have treated it as: a regulatory peptide, a neuropeptide-based anxiolytic, and an immunomodulator. All three framings appear in the literature, and which one is used usually depends on the endpoint being measured in that particular study.
Regulatory status
- United States: no FDA-approved Selank product exists. It has not been through a US new-drug approval pathway, and it is not an FDA-approved indication for anxiety or any other condition.
- Russia: the clinical publications in the verified set were conducted in a Russian regulatory context, where the compound was studied in patients with generalised anxiety disorder and neurasthenia (PMID 18454096).
- Elsewhere: material bearing this name is generally supplied as a research chemical, not as a pharmaceutical product.
How the term is used in peptide research
In the published literature, "Selank" is used narrowly and consistently: it names one specific heptapeptide. Researchers typically pair it with a defined experimental model — restraint stress, foot-shock stress, "social" stress, chronic mild stress, morphine withdrawal, or ethanol exposure — and then report a measured biological endpoint. A functional connectomic analysis grouped Selank with Semax, another Russian-developed regulatory peptide, when comparing their effects on brain network measures (PMID 32342318).
Where the term is misused
- Treated as a "nootropic" product category. Non-scientific sources often list Selank alongside cognitive-enhancement supplements. The verified literature measures stress-model and neurochemical endpoints in animals, plus anxiety-scale outcomes in Russian clinical papers — not general cognitive enhancement in healthy people.
- Confused with Semax. The two are distinct peptides with distinct parent molecules. They appear together in one comparative study (PMID 32342318), which is probably why the names travel together, but they are not interchangeable.
- Described as an approved anti-anxiety medicine internationally. Approval in one jurisdiction is not global approval, and the English-language evidence base is small.
- Called "a benzodiazepine alternative." One rat study examined Selank with diazepam rather than as a substitute for it (PMID 28280289). The framing in that work was combination, not replacement.
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Try it freeRelated terms
| Term | Relationship to Selank |
|---|---|
| Tuftsin | The naturally occurring immune tetrapeptide from which Selank's core sequence is derived; Selank is repeatedly described as its analogue. |
| Semax | A separate Russian-developed regulatory peptide, compared with Selank in a connectomic analysis (PMID 32342318). |
| Anxiolytic | The pharmacological class label most often applied to Selank in the literature. |
| GABAergic neurotransmission | The signalling system whose gene expression was examined in Selank studies (PMID 26924987). |
| BDNF | Brain-derived neurotrophic factor, measured as an endpoint in a rat ethanol-memory study (PMID 31625062). |
| Regulatory peptide | Broad category term used for short endogenous-derived peptides studied for signalling effects. |
What the published literature reports
GABA-related gene expression
Two studies in Frontiers in Pharmacology examined whether Selank altered expression of genes tied to GABAergic neurotransmission. The first reported that Selank administration affected the expression of some of these genes (PMID 26924987). A follow-up compared Selank with GABA itself and with olanzapine in IMR-32 neuroblastoma cells and again reported effects on genes involved in GABAergic signalling (PMID 28293190). Researchers used these findings to argue for a GABA-system-linked mechanism rather than direct receptor binding.
Neuronal and network activity
An electrophysiological study assessed spontaneous synaptic activity of rat hippocampal CA1 neurons and reported that Selank modified it (PMID 28361410). At a coarser scale, the functional connectomic approach examined how Selank and Semax influenced brain network organisation (PMID 32342318).
Behavioural and stress models
In unpredictable chronic mild stress in rats, the study reported that Selank enhanced the anxiety-reducing effect of diazepam (PMID 28280289). A separate rat study reported that Selank attenuated aversive signs of morphine withdrawal (PMID 36322304). In an ethanol model, researchers reported protection against memory impairment alongside changes in BDNF content in the hippocampus and prefrontal cortex (PMID 31625062).
Peripheral and immune endpoints
Because of its tuftsin origin, several groups looked outside the brain. One study reported effects on cytokine levels under "social" stress conditions (PMID 32621722). Two liver-focused papers examined hepatocyte functional state under restraint stress (PMID 28853100) and morphological parameters of rat liver under chronic foot-shock stress (PMID 31243679).
Clinical reports
The human literature in this verified set is Russian-language. One paper examined efficacy and possible mechanisms of Selank as a peptide anxiolytic in generalised anxiety disorder and neurasthenia (PMID 18454096); another addressed optimisation of treatment of anxiety disorders with Selank (PMID 26356395).
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The verified papers listed here were designed around efficacy and mechanism endpoints rather than systematic safety surveillance, and their abstracts do not present structured adverse-event tables. The closest organ-level observations come from the two liver studies, which examined hepatocyte functional state (PMID 28853100) and liver morphology (PMID 31243679) in stressed rats, and the cytokine study under social stress (PMID 32621722). No conclusion about human safety can be drawn from this body of work; the absence of reported harms in a small, mostly preclinical literature is not evidence of safety.
Limits of the evidence
- Most primary data are from rats or cell lines, not humans.
- The human papers are Russian-language and were conducted in a single national research context.
- Endpoints vary widely across studies, which makes pooling or meta-analysis impractical.
- Independent replication outside the originating research tradition is limited.
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- Functional Connectomic Approach to Studying Selank and Semax Effects (Doklady Biological Sciences, 2020)
- Effect of Selank on Morphological Parameters of Rat Liver in Chronic Foot-Shock Stress (Bulletin of Experimental Biology and Medicine, 2019)
- The Influence of Selank on the Level of Cytokines Under the Conditions of "Social" Stress (Current Reviews in Clinical and Experimental Pharmacology, 2021)
- Selank, a Peptide Analog of Tuftsin, Attenuates Aversive Signs of Morphine Withdrawal in Rats (Bulletin of Experimental Biology and Medicine, 2022)
- Effect of Selank on Functional State of Rat Hepatocytes under Conditions of Restraint Stress (Bulletin of Experimental Biology and Medicine, 2017)
- GABA, Selank, and Olanzapine Affect the Expression of Genes Involved in GABAergic Neurotransmission in IMR-32 Cells (Frontiers in Pharmacology, 2017)
- Selank, Peptide Analogue of Tuftsin, Protects Against Ethanol-Induced Memory Impairment by Regulating of BDNF Content in the Hippocampus and Prefrontal Cortex in Rats (Bulletin of Experimental Biology and Medicine, 2019)
- Peptide Selank Enhances the Effect of Diazepam in Reducing Anxiety in Unpredictable Chronic Mild Stress Conditions in Rats (Behavioural Neurology, 2017)
- 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)
- Effect of Selank on Spontaneous Synaptic Activity of Rat Hippocampal CA1 Neurons (Bulletin of Experimental Biology and Medicine, 2017)
- Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission (Frontiers in Pharmacology, 2016)
- Optimization of the treatment of anxiety disorders with selank (Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova, 2015)
Frequently asked questions
What does the word "Selank" mean?▾
Selank is a coined product name, not a descriptive chemical term. It refers to one specific synthetic heptapeptide derived from the immune peptide tuftsin. Study titles in the literature describe it directly as "a peptide analog of tuftsin" (PMID 36322304, PMID 31625062). The name carries no separate meaning beyond identifying that molecule.
Is Selank the same thing as Semax?▾
No. They are two distinct peptides with different parent sequences and different research histories, though both were developed in Russia. They appear together in a functional connectomic analysis that compared their effects on brain network measures (PMID 32342318), which is likely why the names are often mentioned side by side, but they are not interchangeable.
What mechanism do researchers propose for Selank?▾
The most-cited proposal involves the GABA system. Researchers reported that Selank administration affected expression of genes involved in GABAergic neurotransmission (PMID 26924987), and a later study compared it with GABA and olanzapine in IMR-32 cells with similar framing (PMID 28293190). A separate study reported changes in spontaneous synaptic activity of rat hippocampal CA1 neurons (PMID 28361410).
Has Selank been studied in humans?▾
Yes, in a small Russian-language clinical literature. One paper examined its efficacy and possible mechanisms as a peptide anxiolytic in generalised anxiety disorder and neurasthenia (PMID 18454096), and another addressed optimisation of anxiety-disorder treatment with Selank (PMID 26356395). Most other published work in this area used rats or cultured cells rather than human participants.
Is Selank approved by the FDA?▾
No. There is no FDA-approved Selank product in the United States, and it has not gone through a US new-drug approval pathway for any indication. The clinical publications summarised here were conducted in a Russian regulatory context. Elsewhere, material under this name is typically supplied as research-use-only rather than as a pharmaceutical.
What non-brain effects have studies examined?▾
Because Selank derives from an immune peptide, several groups studied peripheral endpoints. One study reported effects on cytokine levels under "social" stress conditions (PMID 32621722). Two others examined rat liver: hepatocyte functional state under restraint stress (PMID 28853100) and liver morphological parameters under chronic foot-shock stress (PMID 31243679).
What are the main limitations of the Selank evidence base?▾
The literature is small, heavily preclinical, and dominated by a single national research tradition. Endpoints differ widely between studies, making pooled analysis impractical, and independent replication outside the originating groups is limited. This page is for educational purposes only and is not medical advice; consult a licensed physician about any health question.
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References
This page summarises published research for education — it is not medical advice, and nothing here is a recommendation to use, purchase, or dose any substance. Study parameters described are what researchers reported, not instructions. Consult a qualified clinician before any health decision.