Selank Peptide: molecular structure, anxiety research, cognitive functions, and experimental evidence

Selank is a synthetic peptide composed of seven amino acids, developed by scientists affiliated with the Institute of Molecular Genetics of the Russian Academy of Sciences. Its structure is based on tuftsine, an endogenous tetrapeptide with the sequence Thr–Lys–Pro–Arg (TKPR). The researchers extended the C-terminus of tuftsine with a fragment of Pro–Gly–Pro (PGP), obtaining the sequence Thr–Lys–Pro–Arg–Pro–Gly–Pro (TKPRPGP). This structural similarity became the basis for research on the activity of Selank in the nervous and immune systems.

The scientific literature on Selank includes behavioral experiments, gene expression analyses, biochemical studies, small clinical trials, and preliminary experiments regarding other physiological systems. An important part of this literature consists of studies related to anxiety. However, learning and memory, neurochemical signaling, inflammatory processes, gastrointestinal physiology, metabolism, liver function, and experimental models of viral infections and tumors were also analyzed.

The strength of the evidence varies significantly between these areas. Observations obtained in cell cultures or in rodents do not allow determining whether a given substance is effective and safe in humans.

What is Selank and what is its connection with tuftsyn?

Selank is a synthetic heptapeptide derived from tuftsyn. Tuftsyn consists of four amino acids and has been studied for its activity related to the immune system.

Selank retains the tuftsin sequence, but contains three additional amino acid residues. This creates a peptide that may differ in stability, metabolism, and biological effects.

The added PGP fragment is an important component of the molecular structure. However, the structural modification alone does not prove that the peptide exhibits greater clinical efficacy.

The researchers investigated whether Selank affects serotonin, dopamine, noradrenaline, gamma-aminobutyric acid (GABA), neurotrophic signaling, and the expression of genes related to immunity.

These are separate biological pathways. A change observed in one of them does not automatically mean that it is responsible for a specific behavioral or clinical effect.

Selank formulations and its chemical variants

In the published studies and descriptions of the Selank preparations, solutions for nasal administration are mentioned, including drops and aerosols, as well as formulations used in other experimental routes of administration.

The olfactory tract is of interest because the nasal mucosa provides different absorption conditions than the alimentary tract.

However, the formulation, concentration, delivery device, and quality of manufacture can all influence the body's exposure. Based on the studies discussed, no delivery route can be considered universally safer or more effective.

Several names appear in discussions about Selank's chemistry:

• Conventional Selank: the unmodified heptapeptide TKPRPGP, which forms the basis of most of the studies discussed in the article.
• N-acetyl-Selank: A chemically modified form that is attributed with potentially different stability or duration of action in the body. Claims of greater activity or clinical efficacy require direct comparative studies.
• Amorphous form of N-acetylselank: Another modified derivative for which the source material indicates a limited number of studies. Its effects should not be automatically equated with the effects of conventional Selank.

These variants should be clearly distinguished in scientific publications. Evidence regarding the original peptide cannot be directly transferred to its modified analogues.

Review of research: what was analyzed?

The cited studies concern Selank in many contexts: behavioral and cognitive experiments, anxiety disorders, regulation of neurotransmitters, expression of immune genes, responses to stress, models of gastrointestinal damage, an experimental metabolic syndrome, liver damage, cardiovascular physiology, models of influenza virus infection, and spontaneous tumors in mammary glands in mice.

The limited number of cited studies included human participants, primarily in the context of anxiety disorders.

Many of the other proposed applications still rely on animal or laboratory results.

Selank, learning, memory and cognitive processes

Changes in memory after exposure to ethanol

Kolik and colleagues studied Selank in rats with memory impairments associated with exposure to ethanol or its withdrawal.

They described changes in cognitive test results and measurements of neurotrophic factor of brain origin (BDNF) in the hippocampus and the prefrontal cortex.

Selank reduced some of the memory and attention disorders and inhibited the increase in BDNF levels observed in this model [1].

Because the response to BDNF depends on the time of measurement, the type of tissue and the experimental conditions, the result should not be simplified to state that increasing or decreasing BDNF is always beneficial.

Learning from mice with weaker initial results

Kozlovskii and Danchev evaluated active avoidance training in rats with relatively poor initial performance in cognitive tasks.

Animals receiving Selank made fewer errors and displayed more correct responses. The effect was observed after the first exposure, and additional changes appeared during subsequent sessions [2].

A related study described an improvement in the conditioning of active avoidance and suggested that the effect on learning may be particularly noticeable under conditions of emotional stress [5].

These experiments measure specific conditional behaviors, not the general intelligence of a person or memory in everyday life.

Cognitive disorders associated with catecholamines

In another mouse model, the researchers disrupted the functioning of the catecholaminergic system during early development, and then evaluated learning, attention, and memory.

Selank was associated with a partial restoration of impaired cognitive parameters [3].

Catecholamines include dopamine and noradrenaline, which are involved in the regulation of attention and behavior.

The experiment justifies further mechanistic studies, but does not confirm its effectiveness in the treatment of neurodevelopmental disorders in humans.

Serotonin metabolism and memory consolidation

Semenova and colleagues analyzed the effect of Selank on serotonin metabolism and the maintenance of learned responses.

They described greater durability of memory traces over a period of approximately 30 days and suggested that exposure during memory consolidation may affect subsequent information retention [4].

The association with serotonin and its metabolites indicates a possible mechanism, but the design of the study does not allow proving a single, exclusive causal pathway.

Experimental disorder of protein synthesis and noradrenergic signaling

The researchers also studied learning disorders caused by actinomycin D, a compound that inhibits transcription and thus disrupts the processes necessary for protein synthesis.

Selank reduced some of the associated deficits and shortened the time required to develop a conditioned response [6].

In a separate model involving damage to the noradrenergic system of the brain, Selank was associated with the recovery of selected learning and memory parameters [7].

Both studies used very specific experimental models. They do not confirm that Selank reverses memory disorders in clinical practice.

Taken together, these results explain why Selank appears in experimental studies of nootropic substances. However, they do not demonstrate reliable improvement in cognitive function in healthy people.

Gene expression, neurotransmission, and immune regulation

Expression of genes related to GABA

Volkova and colleagues analyzed genes related to GABAergic neurotransmission in an experimental model.

Of the 84 genes evaluated, 67 showed significant changes in expression after exposure to Selank. Clear responses were observed approximately one hour after administration [8].

GABA is one of the main inhibitory neurotransmitters, but altered gene expression does not necessarily mean stronger neuronal inhibition or reduced anxiety in a living human being.

In another study, embryonic stem cells IMR-32 were used to analyze GABA, Selank, and olanzapine.

Selank influenced the pattern of gene expression responses to other substances, although it did not itself cause the same changes in the measured GABA system mRNA transcripts [9].

The cellular line results describe molecular interactions under controlled laboratory conditions. They do not constitute evidence that the combination of these substances is clinically effective or safe.

Genes associated with inflammation in the spleen

Studies of Selank and its shorter fragments showed changes in genes related to inflammation in the spleen.

In one experiment, Selank was compared with Gly–Pro and changes in the transcription associated with resistance were observed [10].

In another study, changes were observed in 34 genes related to inflammation, including Bcl6, a regulator important for the differentiation of immune cells [11].

Experiments indicate that the peptide can affect molecular signals associated with immunity, but the direction and consequences of these changes depend on the biological context.

Transcranial hippocampal and cingulate comparisons suggested that the cingulate may show a broader response than the hippocampus for some of the analyzed genes.

The changes included changes in cell signaling pathways, organization of the cytoplasm and inflammatory processes [12].

In another study in mice, changes in the expression of genes for cytokines, chemokines, and receptors were described, especially after six and 24 hours of exposure [13].

These results are best interpreted as evidence of a molecular response, rather than confirmation of immune enhancement.

Expression of genes in the hippocampus

Researchers analyzing hippocampal tissue described changes in the expression of 36 genes after a single or repeated exposure to Selank.

Twenty genes showed similar responses after repeated administration, and several were associated with proteins found in or near the cell membrane [14].

The authors proposed a possible connection with ion transport and neuronal signaling.

This remains a hypothesis based on patterns of gene expression, rather than a confirmed clinical effect.

Human immune markers and experimental stress

In a study involving individuals with depressive or anxiety disorders, the relationship between Selank and changes in the activity of the interleukin 6 (IL-6) gene was described.

The response was observed in patients but not in healthy control participants [15].

IL-6 plays complex roles in the regulation of immunity. Suppressing a specific signal in a specific sample is not equivalent to treating a systemic inflammatory condition.

In rats subjected to social stress, scientists observed an increase in selected inflammatory cytokines.

The 20-day intervention with Selank was associated with lower values of several proinflammatory and anti-inflammatory cytokines [16].

The changes regarding both categories of cytokines highlight the need to describe Selank as a potential immune modulator rather than a compound with uniformly anti-inflammatory effects.

Selank and anxiety: mechanistic and clinical results

Effects on GABA receptors

The molecular review discussed the interactions of Selank with the GABAergic system and evidence consistent with the possibility of modulating the responses of GABA receptors [17].

The possibility of additional allosteric modulation has sparked interest, as GABA signaling plays an important role in the physiology of fear.

However, the proposed receptor mechanism itself does not confirm efficacy or predict the effects of combining with sedative drugs.

Comparison with diazepam in rats subjected to stress

Kasián and colleagues studied Selank, diazepam, and their combination in rats exposed to unpredictable chronic mild stress.

Both interventions used separately were associated with a reduction in anxiety-like behaviors.

In combined conditions, a stronger response was observed in some experimental measurements [18].

The results refer to the animal model and should not be used as instructions for combining drugs.

Clinical studies involving fenazepam

A clinical study compared the regimen consisting of Selank and phenazepam with other treatment conditions in patients with anxiety disorders.

The authors described a previous occurrence of a favorable response and a lower number of selected adverse reactions in the combination therapy group [19].

The study points to questions worth analyzing in larger, independently repeated trials, but does not justify a general recommendation to combine both substances.

In another comparative clinical study concerning phobic anxiety and somatization disorders, a reduction in anxiety symptoms and minor changes in cognitive parameters were described during the use of Selank.

The authors indicated that some effects remained detectable for about a week after the intervention ended [21].

When interpreting the results, the population being studied, the design, and the measurement methods used must be taken into account. The persistence of the effect in one study does not indicate a predictable duration of action in all individuals.

Encephalin metabolism and anxiety

Enkephalins are endogenous peptides involved in pain and stress-related signaling.

Zozulya and colleagues investigated whether Selank could inhibit the enzymes responsible for the breakdown of encaphalins, thereby affecting the time they remain in biological samples [20].

The proposed relationship between encaphalin metabolism and anti-anxiety activity is interesting in mechanistic terms, but it represents only one element of a much more complex neurobiological picture.

Generalized anxiety disorder and neurasthenia

In a study involving 62 people with a recognized generalized anxiety disorder or neurasthenia, Selank was compared with medazepam.

Researchers described improvements in anxiety symptoms and additional changes related to fatigue and mental activation in the Selank group [22].

Parameters related to the metabolism of leu-encephalin were also measured. In some patients, these were lower at the beginning of the study and increased during treatment, especially in participants with generalized anxiety disorder [22].

The results constitute preliminary clinical evidence and do not confirm the equivalence of Selank with standard methods of treating anxiety disorders.

Synaptic signaling and experiments with TP-7

Electrophysiological studies analyzed inhibitory synaptic conduction and discussed the possible effects of Selank and Noopept on neuronal signaling [23].

A separate study of the tuftsin analogue TP-7 showed a reduction in anxiety-like behaviors without corresponding changes in body weight, as well as changes in learning and memory performance [24].

The results regarding TP-7 are relevant for the broader family of peptides, but they should not be automatically considered as results applicable to every formulation of Selank.

Alcohol withdrawal models

In rats with experimentally induced alcohol-related behaviors, Selank reduced some anxiety-like reactions during withdrawal [25].

Another study described changes in pain sensitivity associated with withdrawal, including mechanical allodynia, without simultaneous effects on alcohol consumption [26].

Animal withdrawal models do not demonstrate that Selank is a stable method of treating alcohol dependence or withdrawal syndrome in humans.

Studies of the gastrointestinal tract: ulcers, changes in the large intestine, and the microbiome

Models of gastric ulcers and peptide metabolites

Pavlov and his colleagues studied Selank and peptide fragments in several experimental models of damage to the gastric mucosa.

The researchers described a reduction in the area or severity of ulcers, with different fragments showing activity in different models of damage.

The ATP triad was distinct in the stress-related model, whereas the GP and RP fragments showed activity under other conditions [27].

These distinctions are important because it cannot be assumed that the experimental effects of the metabolite correspond to the action of the unchanged parent peptide.

In a separate study, it was described that Selank and some derivatives limited the area of ulcers in models associated with ethanol and stress, and additional changes occurred after repeated experimental exposure [28].

The proposed mechanisms included effects on blood flow in the stomach, lymphatic circulation, and tissue responses to injury.

These are animal results, not evidence of approved anti-inflammatory treatment.

Morphological changes in the colon associated with stress

Chronic immobilization stress can alter the structure of intestinal tissues and the physiological markers of stress in rodents.

In one experiment, Selank was associated with a reduction in corticosterone levels and less severe morphological changes in the colon associated with stress [29].

The result depends on the specific stress model and the histological measurements used.

The intestinal microbiota during chronic stress

In another study in rats, changes in the population of gut microorganisms were described after prolonged immobilization stress.

Animals receiving Selank showed a different microbial profile than untreated animals subjected to stress, including changes in the population of organisms classified as obligate or opportunistic [30].

The authors discussed possible neurotrophic and immunotropic explanations.

The composition of the microbiome itself does not confirm an improvement in the health of the gastrointestinal tract nor does it allow for a similar response in humans to be predicted.

Blood and lymph flow in the stomach

Additional experimental studies concerned gastric circulation and the activity of lymphatic vessels.

Selank was associated with the maintenance of selected parameters of blood flow during pharmacologically induced gastric stress and with changes in the contractions of lymphatic vessels [31].

These observations provide possible explanations for the physiological results obtained in the ulcer models, but further research is needed.

Brain signaling, neurotrophic factors, and experimental neurological models

Expression of BDNF in the hippocampus

In an animal study, the effect of the reported Selank on BDNF mRNA in the hippocampus was described. Under certain conditions, measurements reached about twice the level compared to the control group [32].

BDNF is involved in the development of neurons, plasticity, and the survival of nerve cells.

However, the change in BDNF expression remains an observation regarding a biomarker, and not evidence of neuroprotection or improvement in cognitive function in humans.

Behavioral reactions related to serotonin

The tuftsyn and TP-7 studies evaluated behavioral responses to stress and changes in serotonin metabolism in rats.

TP-7 correlated with more pronounced responses than tuftsyn in some measurements [33].

In a separate experiment, Selank was studied in mice exposed to apomorphine, which stimulates dopaminergic signaling.

Selank altered behavioral manifestations, and naloxone modified this response, suggesting a possible involvement of pathways related to the opioid system [34].

Another study in rats showed changes in serotonin metabolism after exposure to Selank, especially in the brain stem tissue [35].

The results suggest the involvement of many interconnected neurochemical pathways, rather than a single defined molecular target.

Functional connectivity of the brain

Panikratova and colleagues used a functional connectivity-based approach to study Selank and Semax.

Changes in connectivity have been described, including the relationship between the right amygdala and the right temporal cortex [36].

Functional connectivity describes the statistical relationships between brain signals.

Such a result in itself does not prove an improvement in emotional regulation or clinical benefit.

Excessive activity caused by ethanol and behavioral sensitization

In DBA/2 mice, Selank limited the excessive motor activity induced by ethanol and the development of certain behavioral sensitization reactions.

The results were compared with the effects associated with naloxone in the experimental model used [37].

The model is relevant for research on neurobehavioral responses to alcohol, but it does not support effective intervention in alcohol use disorders.

Models of prenatal hypoxia

In two related studies, adult rats that were exposed to oxygen deficiency during prenatal development were analyzed.

Selank was associated with changes in exploratory activity, sensory attention, learning, and measurements of serotonin or norepinephrine in the brain [38,39].

The studies concern models of developmental damage and cannot be generalized to human cognitive disorders without clinical evidence.

Damage resembling Parkinsonism

In rats with a dopamine system impairment caused by 6-hydroxydopamine, the behavioral effects of Selank and Semax were evaluated.

The results regarding Selank included a reduction in anxiety-like behaviors without a clear improvement in overall motor parameters [40].

Therefore, the experiment should not be presented as evidence that Selank cures Parkinson's disease or restores lost dopaminergic neurons.

Discontinuation of morphine

In a study in rats, a reduction of about 40 percent in the composite index of adverse withdrawal symptoms was described after exposure to Selank.

The changes included more infrequent seizure reactions, eyelid droop, and abnormal body positions.

In the studied conditions, the effect was weaker than in the case of diazepam [41].

The study does not confirm the effectiveness of treatment for opioid withdrawal syndrome in humans.

Behavioral tests related to depression

In models of rats and mice, researchers described post-administration of Selank changes in immobility, behaviors resembling learned helplessness, and parameters related to anhedonia [42].

These tests provide experimental endpoints regarding behavior, but they do not reproduce the full clinical picture of major depression.

Differences between mouse strains

In another study, it was found that responses related to fear and neurochemistry after exposure to Selank differed between mouse strains [43].

This suggests that biological responses may depend on genetics and initial reactivity to stress, even before taking into account differences between animals and humans.

Intracerebral hemorrhage

In the mouse model of cerebral hemorrhage, Selank was associated with improvements in functional parameters.

However, the researchers did not observe a reduction in the volume of the capillary or the swelling surrounding it [44].

Distinguishing between functional and structural damage indicators is crucial for interpreting this study.

Selank and behaviors related to stress

In studies of peptides from the tuftsyn family, including Selank, the adaptive behaviors of rats and mice subjected to stress were analyzed.

Researchers described differences in exploratory behaviors, emotional reactivity, and stress-related test results [45,46].

The publications concern related experiments and should not be automatically counted as independent confirmations of the same effects.

Another study described persistent behavioral changes after exposure to Selank, including reduced fear- or aggression-related responses, increased exploration, and changes in memory or physiological stress parameters [47].

A separate study linked Selank with longer retention of leu-enkephalin in plasma and reduced activity of enzymes that break down enkephalins in mice with different stress response phenotypes [48].

The observations support research on stress-related pathways, but do not confirm the overall effect of stress-relieving interventions in humans.

Metabolic syndrome and lipid parameters

In a mouse experimental model of metabolic syndrome associated with a high-fat diet, the researchers analyzed the effect of Selank on blood lipids, glucose-related parameters, hemostasis, and body weight.

Lower values of total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides were described, as well as changes in coagulation parameters and the course of weight changes [49].

The model does not prove that Selank prevents weight gain, diabetes, or cardiovascular events in humans.

Liver morphology and oxidative stress

Histological changes during chronic stress

Fomenko and his colleagues evaluated the liver tissue of Wistar rat males subjected to chronic stress caused by electric shock pulses to the paws.

The exposure to Selank was associated with less intense hepatocellular necrosis, nuclear and cytoplasmic changes, local necrosis, and swelling of inflammatory cells.

The authors found a clear response in one of the tested groups at a dose of 300 μg/kg [50].

This value describes an animal experiment and does not constitute a dosage recommendation for humans.

Liver enzymes and antioxidant markers

In a separate experiment concerning immobilization stress, aminotransferases in serum and oxidative stress markers in the liver were measured.

Selank was associated with lower values of selected enzymes and malondialdehyde, altered superoxide dismutase activity, and changes in total antioxidant activity [51].

Importantly, reduced superoxide dismutase activity should not be automatically presented as an improvement in antioxidant defense.

The interpretation depends on the entire oxidative stress profile and the experimental context.

Studies of cardiovascular system and hemostasis

Arterial pressure and blood flow through the brain

In an experiment involving cats under sedation, Selank was associated with a reduction in arterial pressure and an increase in cerebral blood flow.

No comparable changes in heart rate frequency, respiratory rate, or acetylcholine-related responses were observed [52].

The acute physiological response in an anesthetized animal does not confirm cardiovascular benefits or safety in humans.

Blood clotting measurements

Thromboelastographic experiments involving gliprolin-derived peptides containing arginine, including the TKPRPGP sequence, showed changes in clot formation and strength consistent with antiplatelet activity under experimental conditions [53].

Such laboratory results do not prove that Selank is a safe anticoagulant drug.

However, they may indicate questions regarding bleeding risk and interactions that require further investigation.

Studies on influenza A virus: laboratory and animal models

In the study of the A/Aichi/2/68 (H3N2) influenza virus, Selank was analyzed in cell and animal experiments.

The researchers described the restriction of viral replication under certain conditions, including after exposure before infection, and changes in interferon alpha expression.

However, no equivalent changes were observed in all of the analyzed immune markers, including IL-4, IL-10, and TNF-alpha [54].

The results are preliminary and do not confirm the prevention of influenza or its treatment in humans.

Experimental results regarding mammary gland tumors

Meshavkin and colleagues studied several oligopeptides in female mice with spontaneous mammary gland tumors.

The article described an approximately fourfold increase in tumors in the control group, compared with a 2.1-fold increase in one of the groups receiving Selank.

The size of the tumors decreased in about one-third of the mice that received Selank.

Survival in the groups receiving the peptides was, according to the authors, 53–70% longer than in the control groups, which corresponds to approximately four to six additional months under the experimental conditions used [55].

These values apply to the animal model that includes several different peptide interventions.

They do not confirm the effectiveness of anti-cancer drugs in humans, do not identify a proven resistance-dependent mechanism, and do not justify replacing established methods of treating cancer.

Routes of administration in studies, exposure and pharmacokinetics

The cited studies include the administration of oral and other experimental methods of delivering the substance.

The original material also mentions drop-in syringes, aerosols, and injection preparations.

However, differences in the quality of formulations, inertness, absorption, and the risk associated with the route of administration make simple comparisons impossible.

The source provides a bioavailability reported as 92.8%, detectable in the blood within 30 seconds, a half-life in the blood of several minutes, and effects lasting for several hours.

However, the material provided does not assign these exact pharmacokinetic values to a clearly identifiable study among the 55 cited publications.

Therefore, they should be treated as unverified source claims, rather than established fixed pharmacokinetic values.

Similarly, the number of doses of aerosol in the package and the declared start and duration of action depend on the characteristics of the specific product and cannot be generalized.

Why are the original dosing instructions cautious?

The article provided contains specific instructions for self-administration, the length of cycles, and the declared daily amount of 300–900 mg.

However, a verifiable clinical basis for these recommendations has not been presented, and the unit or dose size may be incorrect.

In this version they were not repeated as practical instructions.

The experimental doses found in individual studies only describe the protocols used and cannot be directly translated into appropriate dosing regimens for humans.

Safety, side effects and interactions with medications

The source material describes Selank as generally well-tolerated and mentions possible sensory discomfort or allergic reactions.

However, the cited evidence does not allow for determining the full safety profile in all formulations, populations, or with prolonged exposure.

The absence of published reports of overdose does not prove that overdose cannot occur.

Interactions remain particularly uncertain.

Laboratory and animal studies on GABAergic substances, diazepam, phenazepam or other psychoactive substances do not confirm the safety of their combined use.

The evidence reviewed is also insufficient to support claims that Selank does not cause addiction, is appropriate during pregnancy or breastfeeding, or can replace prescribed anti-anxiety medications.

Issues related to individual treatment require evaluation by a qualified specialist.

How strong are the scientific evidence regarding Selank?

The most substantiated conclusion from the submitted material is that Selank has been studied in several biological systems and measurable effects have been observed in selected experimental models.

Clinical evidence in humans is much more limited and focuses on anxiety-related disorders, with relatively small research populations.

Some of the publications are older, relate to specialized experimental endpoints, or come from related research teams.

The source does not contain sufficient information to confirm robust independent replication of the results, comprehensive monitoring of adverse events, or international regulatory approval for all proposed indications.

Therefore, it is worth distinguishing three categories: laboratory changes observed, behavioral or physiological results in animals, and clinical results concerning patients.

The change in gene expression is not the result of treatment. The improvement in the rodents' maze performance does not prove better memory in humans, and a small comparative clinical trial does not necessarily confirm long-term efficacy or safety.

Summary

Selank is a synthetic heptapeptide derived from tuftsyn, for which there is a significant body of exploratory research.

The published papers describe the effects on anxiety-related behaviors, learning tasks, neurotransmitter signaling, neurotrophic markers, immune gene expression, gastrointestinal stress patterns, metabolism, liver tissue, cardiovascular physiology, and experimental infection and tumor systems.

The most clinically relevant part of the cited literature concerns anxiety-related studies, while many broader proposed applications remain in the preclinical stage.

The results justify scientific interest, but do not allow for broad claims about proven therapeutic benefits.

More rigorous, independently repeated studies in humans are needed to establish clinical results, formulation-dependent pharmacokinetics, interactions, and long-term safety.

Most frequently asked questions about Selank

Does Selank cause addiction?

The sources provided do not confirm that Selank causes addiction, but they also do not contain sufficient long-term data in humans to prove the absence of such a risk. Experimental results should not be used to make categorical claims regarding safety.

Can Selank cause insomnia or increased alertness?

Individual reports may describe sleep disorders or changes in alertness levels, but the cited studies do not establish their frequency or mechanism. Such symptoms should not be automatically attributed to changes in norepinephrine without adequate evidence.

Are the interactions between Selank and other medications known?

Information regarding interactions is incomplete. Studies of GABAergic pathways and connections with psychoactive drugs indicate that potential interactions require analysis, not that such combinations are safe. Changes in pharmacotherapy should be discussed with a doctor.

Is the long-term use of Selank supported by clinical studies?

The available literature does not confirm long-term safety or efficacy in different populations. Short-term experiments and limited clinical observations do not allow answering questions regarding prolonged exposure.

Can Selank replace Xanax or another benzodiazepine?

The available evidence does not justify replacing alprazolam (Xanax) or other prescribed benzodiazepines with Selank. Rapid discontinuation of benzodiazepines can be dangerous, and the cited animal studies and small clinical trials do not support a validated treatment replacement or discontinuation scheme.

What is known about the stability of Selank during travel?

Stability depends on the specific formulation, packaging, temperature, and validated storage conditions. The provided studies do not establish a universal number of days for safe transport or a standard method for transporting all Selank preparations.

Does Selank increase or decrease BDNF levels?

The experimental literature described both directions of change, depending on the tissue, model, time, and type of measurement. In one study in rats, a reduction in elevated BDNF responses was observed after ethanol-related disorders [1], whereas others showed increased mRNA expression of BDNF in the hippocampus under different conditions [32]. The results do not have to be contradictory, as they pertain to different experimental contexts.

Is Selank a recognized treatment method for anxiety disorders?

The source material includes clinical studies describing beneficial results related to anxiety [19,21,22]. However, these observations alone do not confirm efficacy in all populations or equivalence with established treatment methods. Regulatory status and clinical recommendations vary by country.

How was Selank administered in scientific studies?

The source describes the oral preparations and other experimental routes of administration. The route used in the study does not constitute a recommendation for self-administration, and the differences in formulation and dosage remain significant.

References

1. Kolik, L. G., Nadorova, A. V., Antipova, T. A., Kruglov, S. V., Kudrin, V. S., & Durnev, A. D. (2019). 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, 167(5), 641-644. https://doi.org/10.1007/s10517-019-04588-9 https://pubmed.ncbi.nlm.nih.gov/31625062/
2. Kozlovskii, I. I., & Danchev, N. D. (2003). The optimizing action of the synthetic peptide Selank on a conditioned active avoidance reflex in rats. Neuroscience and behavioural physiology, 33(7), 639-643. https://doi.org/10.1023/a:1024444321191 https://pubmed.ncbi.nlm.nih.gov/14552529/
3. Semenova, T. P., Kozlovskaya, M. M., Zakharova, N. M., Kozlovskii, I. I., & Zuikov, A. V. (2007). Effect of selank on cognitive processes after damage inflicted to the cerebral catecholamine system during early ontogeny. Bulletin of experimental biology and medicine, 144(5), 689-691. https://doi.org/10.1007/s10517-007-0406-2 https://pubmed.ncbi.nlm.nih.gov/18683497/
4. Semenova, T. P., Kozlovskiĭ, I. I., Zakharova, N. M., & Kozlovskaia, M. M. (2010). Eksperimental'naia i klinicheskaia farmakologiia, 73(8), 2-5. https://pubmed.ncbi.nlm.nih.gov/20919548/
5. Kozlovskiĭ, I. I., & Danchev, N. D. (2002). Optimiziruiushchee deĭstvie sinteticheskogo peptida Selanka na uslovnyĭ refleks aktivnogo izbeganiia u krys [Optimizing action of synthetic peptide Selank on active avoidance conditioning test in rats]. Zhurnal vysshei nervnoi deiatelnosti imeni I P Pavlova, 52(5), 579-584. https://pubmed.ncbi.nlm.nih.gov/12449836/
6. Kozlovskiĭ, I. I., Belozertsev, F. I.u, Andreeva, L. A., & Kozlovskaia, M. M. (2013). Eksperimental'naia i klinicheskaia farmakologiia, 76(12), 3-7. https://pubmed.ncbi.nlm.nih.gov/24605419/
7. Kozlovskiĭ, I. I., Belozertsev, I.uF., Semenova, T. P., Zuĭkov, A. V., & Kozlovskaia, M. M. (2008). Eksperimental'naia i klinicheskaia farmakologiia, 71(2), 3-7. https://pubmed.ncbi.nlm.nih.gov/18488898/
8. Volkova, A., Shadrina, M., Kolomin, T., Andreeva, L., Limborska, S., Myasoedov, N., & Slominsky, P. (2016). Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission. Frontiers in pharmacology, 7, 31. https://doi.org/10.3389/fphar.2016.00031 https://pubmed.ncbi.nlm.nih.gov/26924987/
9. Filatova, E., Kasian, A., Kolomin, T., Rybalkina, E., Alieva, A., Andreeva, L., Limborska, S., Myasoedov, N., Pavlova, G., Slominsky, P., & Shadrina, M. (2017). GABA, Selank, and Olanzapine Affect the Expression of Genes Involved in GABAergic Neurotransmission in IMR-32 Cells. Frontiers in pharmacology, 8, 89. https://doi.org/10.3389/fphar.2017.00089 https://pubmed.ncbi.nlm.nih.gov/28293190/
10. Kolomin, T., Morozova, M., Volkova, A., Shadrina, M., Andreeva, L., Slominsky, P., Limborska, S., & Myasoedov, N. (2014). The temporary dynamics of inflammation-related gene expression under tuftsin analog Selank action. Molecular immunology, 58(1), 50-55. https://doi.org/10.1016/j.molimm.2013.11.002 https://pubmed.ncbi.nlm.nih.gov/24291245/
11. Kolomin, T., Shadrina, M., Andreeva, L., Slominsky, P., Limborska, S., & Myasoedov, N. (2011). Expression of inflammation-related genes in mouse spleen under tuftsin analog Selank. Regulatory peptides, 170(1-3), 18-23. https://doi.org/10.1016/j.regpep.2011.05.001 https://pubmed.ncbi.nlm.nih.gov/21609736/
12. A. Kolomin; M. I. Shadrina; Ya. V. Agniullin; S. I. Shram; P. A. Slominskii; S. A. Limborska; N. F. Myasoedov (2010). Transcriptomic response of rat hippocampus and spleen cells to single and chronic administration of the peptide selank. , 430(1), 5-6. doi:10.1134/s1607672910010023  https://sci-hub.mksa.top/10.1134/s1607672910010023
13. Kolomin, T. A., Shadrina, M. I., Slominskiĭ, P. A., Limborskaia, S., & Miasoedov, N. F. (2011). Genetics, 47(5), 711-714. https://pubmed.ncbi.nlm.nih.gov/21786679/
14. Kolomin, T. A., Agapova, T. I.u, Agniullin, I.aV., Shram, S. I., Shadrina, M. I., Slominskiĭ, P. A., Limborskaia, S. A., & Miasoedov, I. F. (2013). Zhurnal vysshei nervnoi deiatelnosti imeni I P Pavlova, 63(3), 365-374. https://doi.org/10.7868/s0044467713030052 https://pubmed.ncbi.nlm.nih.gov/24450168/
15. Uchakina, O. N., Uchakin, P. N., Miasoedov, N. F., Andreeva, L. A., Shcherbenko, V. E., Mezentseva, M. V., Gabaeva, M. V., Sokolov, O. I.u, Zozulia, A. A., & Ershov, F. I. (2008). Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 108(5), 71-75. https://pubmed.ncbi.nlm.nih.gov/18577961/
16. Leonidovna, Y. A., Aleksandrovna, S. M., Aleksandrovna, T. A., Aleksandrovna, B. O., Fedorovich, M. N., & Aleksandrovna, A. L. (2021). The Influence of Selank on the Level of Cytokines Under the Conditions of „Social” Stress. Current reviews in clinical and experimental pharmacology, 16(2), 162-167. https://doi.org/10.2174/1574884715666200704152810 https://pubmed.ncbi.nlm.nih.gov/32621722/
17. Vyunova, T. V., Andreeva, L., Shevchenko, K., & Myasoedov, N. (2018). Peptide-based Anxiolytics: The Molecular Aspects of Heptapeptide Selank Biological Activity. Protein and peptide letters, 25(10), 914-923. https://doi.org/10.2174/0929866525666180925144642 https://pubmed.ncbi.nlm.nih.gov/30255741/
18. Kasian, A., Kolomin, T., Andreeva, L., Bondarenko, E., Myasoedov, N., Slominsky, P., & Shadrina, M. (2017). Peptide Selank Enhances the Effect of Diazepam in Reducing Anxiety in Unpredictable Chronic Mild Stress Conditions in Rats. Behavioural neurology, 2017, 5091027. https://doi.org/10.1155/2017/5091027 https://pubmed.ncbi.nlm.nih.gov/28280289/
19. Medvedev, V. E., Tereshchenko, O. N., Kost, N. V., Ter-Israelyan, A. Y., Gushanskaya, E. V., Khobanu, I. K., Sokolov, O. Y., & Myasoedov, N. F. (2015). Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 115(6), 33-40. https://doi.org/10.17116/jnevro20151156133-40 https://pubmed.ncbi.nlm.nih.gov/26356395/
20. Zozulya, A. A., Kost, N. V., Yu Sokolov, O., Gabaeva, M. V., Grivennikov, I. A., Andreeva, L. N., Zolotarev, Y. A., Ivanov, S. V., Andryushchenko, A. V., Myasoedov, N. F., & Smulevich, A. B. (2001). The inhibitory effect of Selank on enkephalin-degrading enzymes as a possible mechanism of its anxiolytic activity. Bulletin of experimental biology and medicine, 131(4), 315-317. https://doi.org/10.1023/a:1017979514274 https://pubmed.ncbi.nlm.nih.gov/11550013/
21. Medvedev, V. E., Tereshchenko, O. N., Israelian, A. I.u, Khobanu, I. K., Kost, N. V., Sokolov, O. I.u, & Miasoedov, N. F. (2014). Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 114(7), 17-22. https://pubmed.ncbi.nlm.nih.gov/25176261/
22. Zozulia, A. A., Neznamov, G. G., Siuniakov, T. S., Kost, N. V., Gabaeva, M. V., Sokolov, O. I.u, Serebriakova, E. V., Siranchieva, O. A., Andriushenko, A. V., Telesheva, E. S., Siuniakov, S. A., Smulevich, A. B., Miasoedov, N. F., & Seredenin, S. B. (2008). Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 108(4), 38-48. https://pubmed.ncbi.nlm.nih.gov/18454096/
23. Skrebitskiĭ, V. G., Kondratenko, R. V., Povarov, I. S., & Dereviagin, V. I. (2011). Rossiiskii fiziologicheskii zhurnal imeni I.M. Sechenova, 97(11), 1169-1178. https://pubmed.ncbi.nlm.nih.gov/22390072/
24. Czabak-Garbacz, R., Cygan, B., Wolanski, L., & Kozlovsky, I. (2006). Influence of long-term treatment with tuftsin analogue TP-7 on the anxiety-phobic states and body weight. Pharmacological reports : PR, 58(4), 562-567. https://pubmed.ncbi.nlm.nih.gov/16963804/
25. Kolik, L. G., Nadorova, A. V., & Kozlovskaya, M. M. (2014). Efficacy of peptide anxiolytic selank during modeling of withdrawal syndrome in rats with stable alcoholic motivation. Bulletin of experimental biology and medicine, 157(1), 52-55. https://doi.org/10.1007/s10517-014-2490-4 https://pubmed.ncbi.nlm.nih.gov/24913576/
26. Kozlovskiĭ, I. I., Andreeva, L. A., Kozlovskaia, M. M., Nadorova, A. V., & Kolik, L. G. (2012). Eksperimental'naia i klinicheskaia farmakologiia, 75(2), 10-13. https://pubmed.ncbi.nlm.nih.gov/22550852/
27. Pavlov, T. S., Samonina, G. E., Bakaeva, Z. V., Zolotarev, Y. A., & Guseva, A. A. (2007). Selank and its metabolites maintain homeostasis in the gastric mucosa. Bulletin of experimental biology and medicine, 143(1), 51-53. https://doi.org/10.1007/s10517-007-0014-1 https://pubmed.ncbi.nlm.nih.gov/18019011/
28. Pavlov, T. S., Samonina, G. E., Andreeva, L. A., Myasoedov, N. F., & Ashmarin, I. P. (2004). A new property of the synthetic anxiolytic Selank and its derivatives. Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections, 397, 281-283. https://doi.org/10.1023/b:dobs.0000039692.94366.2c https://sci-hub.mksa.top/10.1023/b:dobs.0000039692.94366.2c
29. Mukhina, A. Y., Mishina, E. S., Bobyntsev, I. I., Medvedeva, O. A., Svishcheva, M. V., Kalutskii, P. V., Andreeva, L. A., & Myasoedov, N. F. (2020). Morphological Changes in the Large Intestine of Rats Subjected to Chronic Restraint Stress and Treated with Selank. Bulletin of experimental biology and medicine, 169(2), 281-285. https://doi.org/10.1007/s10517-020-04868-9 https://pubmed.ncbi.nlm.nih.gov/32651826/
30. Mukhina, A. Y., Medvedeva, O. A., Svishcheva, M. V., Shevchenko, A. V., Efremova, N. N., Bobyntsev, I. I., Kalutskii, P. V., Andreeva, L. A., & Myasoedov, N. F. (2019). State of Colon Microbiota in Rats during Chronic Restraint Stress and Selank Treatment. Bulletin of experimental biology and medicine, 167(2), 226-228. https://doi.org/10.1007/s10517-019-04496-y https://pubmed.ncbi.nlm.nih.gov/31236882/
31. Pavlov, T. S., Sanzhieva, L. T.s, Samonina, G. E., Sergeev, V. I., & Lelekova, T. V.. (2005). Rossiiskii fiziologicheskii zhurnal imeni I.M. Sechenova, 91(2), 178-183. https://pubmed.ncbi.nlm.nih.gov/15835541/
32. S. Inozemtseva; E. A. Karpenko; O. V. Dolotov; N. G. Levitskaya; A. A. Kamensky; L. A. Andreeva; I. A. Grivennikov (2008). Intranasal administration of the peptide Selank regulates BDNF expression in the rat hippocampus in vivo. , 421(1), 241-243. doi:10.1134/s0012496608040066  https://sci-hub.mksa.top/10.1134/s0012496608040066
33. Seredenin, S. B., Semenova, T. P., Kozlovskaia, M. M., Medvinskaya, N. I., & Nezovibat’ko, V. N. (1995). The characteristics of the anxiolytic action of taftsin and its analog TP-7 on behavior and serotonin metabolism in the brain of rats with chronic deprivation of serotoninergic system activity. Eksperimental'naia i klinicheskaia farmakologiia, 58(6), 3-6. https://pubmed.ncbi.nlm.nih.gov/8704608/
34. Meshavkin, V. K., Kost, N. V., Sokolov, O. Y., Zolotarev, Y. A., Myasoedov, N. F., & Zozulya, A. A. (2006). Naloxone-blocked depressant effect of anxiolytic selank on apomorphine-induced behavioral manifestations of hyperfunction of dopamine system. Bulletin of experimental biology and medicine, 142(5), 598-600. https://doi.org/10.1007/s10517-006-0428-1 https://pubmed.ncbi.nlm.nih.gov/17415472/
35. Semenova, T. P., kozlovskiĭ, I. I., Zakharova, N. M., & Kozlovskaia, M. M. (2009). Eksperimental'naia i klinicheskaia farmakologiia, 72(4), 6-8. https://pubmed.ncbi.nlm.nih.gov/19803361/
36. Panikratova, Y. R., Lebedeva, I. S., Sokolov, O. Y., Rumshiskaya, A. D., Kupriyanov, D. A., Kost, N. V., & Myasoedov, N. F. (2020). Functional Connectomic Approach to Studying Selank and Semax Effects. Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections, 490(1), 9-11. https://doi.org/10.1134/S001249662001007X https://pubmed.ncbi.nlm.nih.gov/32342318/
37. Kolik, L. G., Nadorova, A. V., & Seredenin, S. B. (2016). Selank Inhibits Ethanol-Induced Hyperlocomotion and Manifestation of Behavioral Sensitization in DBA/2 Mice. Bulletin of experimental biology and medicine, 162(1), 56-59. https://doi.org/10.1007/s10517-016-3544-6 https://pubmed.ncbi.nlm.nih.gov/27878720/
38. Semenova, T. P., Kozlovskaia, M. M., Zuĭkov, A. V., Kozlovskiĭ, I. I., Zakharova, N. M., & Andreeva, L. A. (2006). Rossiiskii fiziologicheskii zhurnal imeni I.M. Sechenova, 92(11), 1332-1338. https://pubmed.ncbi.nlm.nih.gov/17385425/
39. Semenova, T. P., Kozlovskaya, M. M., Zuikov, A. V., Kozlovskii, I. I., Zakharova, N. M., & Andreeva, L. A. (2008). Use of Selank to correct measures of integrative brain activity and biogenic amine levels in adult rats resulting from antenatal hypoxia. Neuroscience and behavioural physiology, 38(2), 203-207. https://doi.org/10.1007/s11055-008-0030-2 https://pubmed.ncbi.nlm.nih.gov/18197389/
40. Slominsky, P. A., Shadrina, M. I., Kolomin, T. A., Stavrovskaya, A. V., Filatova, E. V., Andreeva, L. A., Illarioshkin, S. N., & Myasoedov, N. F. (2017). Peptides semax and selank affect the behaviour of rats with 6-OHDA-induced PD-like parkinsonism. Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections, 474(1), 106-109. https://doi.org/10.1134/S0012496617030048 https://pubmed.ncbi.nlm.nih.gov/28702721/
41. Konstantinopolsky, M. A., Chernyakova, I. V., & Kolik, L. G. (2022). Selank, a Peptide Analog of Tuftsin, Attenuates Aversive Signs of Morphine Withdrawal in Rats. Bulletin of experimental biology and medicine, 173(6), 730-733. https://doi.org/10.1007/s10517-022-05624-x https://pubmed.ncbi.nlm.nih.gov/36322304/
42. Sarkisova, K. I.u, Kozlovskiĭ, I. I., & Kozlovskaia, M. M. (2008). Zhurnal vysshei nervnoi deiatelnosti imeni I P Pavlova, 58(2), 226-237. https://pubmed.ncbi.nlm.nih.gov/18661785/
43. Narkevich, V. B., Kudrin, V. S., Klodt, P. M., Pokrovskiĭ, A. A., Kozlovskaia, M. M., Maĭskiĭ, A. I., & Raevskiĭ, K. S. (2008). Eksperimental'naia i klinicheskaia farmakologiia, 71(5), 8-12. https://pubmed.ncbi.nlm.nih.gov/19093364/
44. Skvortsova, V. I., Tvorogova, T. V., Dubina, A. I., Burenchev, D. V., Gubskiĭ, L. V., Stakhovskaia, L. V., & Povarova, O. V.. (2009). Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova, 109(12 Suppl 2), 62-66. https://pubmed.ncbi.nlm.nih.gov/20873405/
45. Kozlovskaya, M. M., Kozlovskii, I. I., Val’dman, E. A., & Seredenin, S. B. (2003). Selank and short peptides of the tuftsin family in the regulation of adaptive behavior in stress. Neuroscience and behavioural physiology, 33(9), 853-860. https://doi.org/10.1023/a:1025988519919 https://pubmed.ncbi.nlm.nih.gov/14969422/
46. Kozlovskaia, M. M., Kozlovskiĭ, I. I., Val’dman, E. A., & Seredenin, S. B. (2002). Selank and short peptides of taftsin in regulation of adaptive behavior of animals in stress. Rossiiskii fiziologicheskii zhurnal imeni I.M. Sechenova, 88(6), 751-761. https://pubmed.ncbi.nlm.nih.gov/12154572/
47. (2008). Zhurnal evoliutsionnoi biokhimii i fiziologii, 44(3), 284-290. https://pubmed.ncbi.nlm.nih.gov/18727417/
48. Sokolov, O. Y., Meshavkin, V. K., Kost, N. V., & Zozulya, A. A. (2002). Effects of Selank on behavioral reactions and activities of plasma enkephalin-degrading enzymes in mice with different phenotypes of emotional and stress reactions. Bulletin of experimental biology and medicine, 133(2), 133-135. https://doi.org/10.1023/a:1015582302311 https://pubmed.ncbi.nlm.nih.gov/12432865/
49. Mjasoedov, N. F., Andreeva, L. A., Grigorjeva, M. E., Obergan, T. Y., Shubina, T. A., & Lyapina, L. A. (2014). The influence of Selank on the parameters of the haemostasis system, lipid profile, and blood sugar level in the course of experimental metabolic syndrome. Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections, 458, 267-270. https://doi.org/10.1134/S0012496614050020 https://pubmed.ncbi.nlm.nih.gov/25371249/
50. Fomenko, E. V., Bobyntsev, I. I., Ivanov, A. V., Belykh, A. E., Andreeva, L. A., & Myasoedov, N. F. (2019). Effect of Selank on Morphological Parameters of Rat Liver in Chronic Foot-Shock Stress. Bulletin of experimental biology and medicine, 167(2), 293-296. https://doi.org/10.1007/s10517-019-04512-1 https://pubmed.ncbi.nlm.nih.gov/31243679/
51. Fomenko, E. V., Bobyntsev, I. I., Kryukov, A. A., Ivanov, A. V., Andreeva, L. A., & Myasoedov, N. F. (2017). Effect of Selank on Functional State of Rat Hepatocytes under Conditions of Restraint Stress. Bulletin of experimental biology and medicine, 163(4), 415-418. https://doi.org/10.1007/s10517-017-3817-8 https://pubmed.ncbi.nlm.nih.gov/28853100/
52. Gan’shina, T. S., & Kozlovskiĭ, I. I. (2005). Eksperimental'naia i klinicheskaia farmakologiia, 68(4), 33-35. https://pubmed.ncbi.nlm.nih.gov/16193654/
53. Rogozinskaya, E. Y., & Lyapina, M. G. (2017). Anticoagulant Effects of Arginine-Containing Peptides of the Glyproline Family (His-Phe-Arg-Trp-Pro-Gly-Pro and Thr-Lys-Pro-Arg-Pro-Gly-Pro) Revealed by Thromboelastography. Bulletin of experimental biology and medicine, 164(2), 170-172. https://doi.org/10.1007/s10517-017-3950-4 https://pubmed.ncbi.nlm.nih.gov/29181670/
54. Ershov, F. I., Uchakin, P. N., Uchakina, O. N., Mezentseva, M. V., Alekseeva, L. A., & Miasoedov, N. F. (2009). Voprosy virusology, 54(5), 19-24. https://pubmed.ncbi.nlm.nih.gov/19882898/
55. Meshavkin, V. K., Kost, N. V., Sokolov, O. Y., Andreeva, L. A., & Myasoedov, N. F. (2013). The influence of oligopeptides on spontaneous carcinogenesis in mice. Doklady biological sciences : proceedings of the Academy of Sciences of the USSR, Biological sciences sections, 449, 79-81. https://doi.org/10.1134/S0012496613020087 https://sci-hub.mksa.top/10.1134/S0012496613020087