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Selank

Tier 2 · Preclinical
Also known as TP-7

The strongest evidence present is Tier 1 human clinical work: an fMRI study in 52 healthy participants examining resting-state functional connectivity (src-17), a comparator-controlled trial of 62 patients versus medazepam (src-1, src-3), and a controlled trial of Selank plus phenazepam (src-30). However, most mechanistic detail comes from Tier 2 animal, in vitro and small Russian studies, and much of the descriptive material comes from Tier 3 reference, vendor and practitioner sites. Long-term safety data is described as limited, and several specific figures (BDNF percentages, HAM-A reduction, FDA Category 2 status) rest on single Tier-3 sources.

Half-life
~0.04 h
Routes
Intranasal · Subcutaneous injection
Goals
Anxiety and mood · Cognitive enhancement · Stress resilience · Immune modulation
Cost / mg
Not recorded

How it works

Selank is a lab-made seven-amino-acid peptide built from tuftsin, a natural immune-signaling fragment of human antibody (IgG), with a short tail added to make it last longer in the body. Sources describe it as producing calming (anxiolytic), memory-supporting (nootropic) and immune-modulating effects. Rather than binding the same site as Valium-type drugs, animal studies report it fine-tunes the brain's main calming system (GABA) indirectly, nudges serotonin and dopamine activity, boosts growth factors like BDNF, and slows the breakdown of the body's own pain- and mood-regulating enkephalins. Reviews note its overall profile resembles low-dose tranquilizers but is reported without the amnesia, withdrawal or dependence that accompany benzodiazepines.

Overview

What Selank Is

Reference sites describe Selank (alias TP-7, CAS 129954-34-3) as a synthetic heptapeptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro, developed in the late 1990s at the Institute of Molecular Genetics of the Russian Academy of Sciences (src-4, src-17), in cooperation with the V.V. Zakusov Research Institute of Pharmacology according to one sports-medicine site (src-9). Reviews describe it as a synthetic analog of the endogenous tetrapeptide tuftsin (Thr-Lys-Pro-Arg, a fragment of the human IgG heavy chain discovered in 1970 whose documented activity is immune stimulation of phagocytic cells), extended at the C-terminus by a Pro-Gly-Pro tail to improve metabolic stability and prolong duration (src-2, src-6, src-8, src-37). A vendor site notes that with three of its seven residues being proline, most internal bonds are resistant to common proteases (src-8). Sources agree the molecular weight is approximately 751.9 Da, though they disagree on the molecular formula (src-8 and src-11 give C33H57N11O9; src-9 gives C37H51N11O9).

Regulatory Status

Reference sites report Selank was registered by the Russian Federation Ministry of Health in 2009 and approved for medical use as an anxiolytic and nootropic drug indicated for generalized anxiety disorder (GAD) and neurasthenia in Russia and Ukraine, marketed as a 0.15% intranasal solution (brand name Selanc), typically in 14-day treatment courses (src-4, src-13, src-18, src-45). A podcast states it was made over-the-counter in Russia in 2017 (src-14). A vendor site and dosing guide state Selank is not approved by the FDA or any other Western regulator (src-8, src-41). One Tier-3 guide states that 'as of April 2026' Selank is classified as an FDA Category 2 bulk drug substance (src-46) — this appears in only one source and carries a prospective date.

Clinical Evidence

  • A 2008 clinical study reported anxiolytic effects in patients with GAD and neurasthenia similar to medazepam, across 62 patients (30 Selank, 32 medazepam), and additionally reported antiasthenic and psychostimulant effects (src-1, src-3). The study observed decreased tau(1/2) leu-enkephalin levels correlating with disease duration and symptom severity, and that Selank treatment increased this parameter, mostly in GAD patients (src-1).
  • An fMRI study in 52 healthy participants (PMID:32342318) reported effects on whole-brain resting-state functional connectivity, notably between the right amygdala and fusiform, temporal and parahippocampal regions, assessed at 5 and 20 minutes post-injection (src-17).
  • A controlled trial of 30 patients on phenazepam monotherapy versus 40 on Selank plus phenazepam reported that adding Selank decreased phenazepam side effects (attention/memory impairment, asthenia, sedation, sexual disturbances, emotional indifference, orthostatism), achieved phenazepam's positive HDRS effect earlier, and improved quality of life (src-30).
  • A Tier-3 review cites Kozlovskaya et al. (2003) reporting a 62% reduction in HAM-A scores (p<0.01 vs placebo) with onset within 3-5 days and no sedation, cognitive impairment or withdrawal (src-5) — this specific figure comes from a single Tier-3 source. A guide states Russian clinical data report anxiolytic activity in GAD with no sedation in the comparator-controlled trial (src-13).

Reviews note that clinical studies have shown similarity between Selank's spectrum of physiological effects and classical benzodiazepines such as diazepam and phenazepam (src-2, src-16, src-24, src-27).

Preclinical Evidence

Animal studies report pronounced anxiolytic activity and neuropsychotropic, antidepressant and antistress effects that relieve aggression and fear reactions, plus nootropic action on memory and learning and marked immunomodulatory activity (src-2, src-8, src-9). In an elevated plus maze and unpredictable chronic mild stress model, rat studies reported Selank's anxiolytic effect comparable to classical benzodiazepines, with individual Selank most effective against course-induced elevated anxiety and a diazepam-plus-Selank combination most effective under chronic mild stress (src-6, src-31). A rat study reported a single 0.3 mg/kg IP injection reduced the total morphine withdrawal index by 39.6% (comparable but slightly inferior to diazepam 2 mg/kg at 49.3%) (src-22, src-13). Foot-shock and social-stress rat studies reported hepatoprotective and anti-inflammatory effects, including reductions in IL-1β and IL-6 and restoration of the hepatocyte nucleus/cytoplasm ratio, with maximum stress-limiting effect at 300 μg/kg (src-23, src-28). A review of tuftsin analogues notes tuftsin derivatives show anti-tumor, anti-inflammatory, antimicrobial and anti-viral activity and are used in vaccines (src-21).

Caveats

As the sources themselves note, most mechanistic evidence comes from rat models, in vitro systems and small Russian clinical studies rather than large human trials; the largest cited human trial had 62 patients and the fMRI study 52 healthy participants, and long-term safety data is described as limited (src-15, src-60). A vendor site highlights that the Western research vial is sold as an injectable, whereas the approved Russian product and all published evidence use the intranasal route (src-8, src-35).

What the research shows

239 findings extracted from the 31 sources cited below, strongest evidence first within each group. Every one links to the source it came from.

What human studies found

Based on 4 human trial findings, 13 human study findings, 19 animal findings, 1 in vitro finding and 10 expert opinion findings.

  • human trialSelank combined with phenazepam decreased the level of undesirable side-effects of phenazepam including attention and memory impairment, asthenia, sedation, increase in sleep duration, sexual disturbances, emotional indifference and orthostatism during the course of treatment and after tranquilizer withdrawal3

  • human trialThe positive effect of phenazepam was achieved earlier in the optimization of treatment with selank on HDRS3

  • human trialCombined treatment with selank and phenazepam had a positive impact on quality-of-life compared to phenazepam monotherapy3

  • human trialZozulia 2008 demonstrated anxiolytic efficacy comparable to medazepam in 62 patients with generalized anxiety disorder and neurasthenia26

  • human studySelank showed anxiolytic effects in patients with generalized anxiety disorder (GAD) and neurasthenia, with effects similar to medazepam1

  • human studySelank had antiasthenic and psychostimulant effects in addition to anxiolytic effects1

  • human studyClinical studies have shown the similarity of the spectrum of physiological effects of Selank and classical benzodiazepines, such as diazepam and phenazepam, suggesting a similar basis of their mechanism of action4

  • human studyClinical studies have shown the similarity of the spectrum of physiological effects of Selank and classical benzodiazepines, such as diazepam and phenazepam5

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  • human studyClinical studies have shown that Selank had an anxiolytic effect comparable to that of classical benzodiazepine drugs11

  • human studyThirty-two documents concern activity of tuftsin in the human organism13

  • human studyClinical studies have shown the similarity of the spectrum of physiological effects of Selank and classical benzodiazepines, such as diazepam and phenazepam14

  • human studySelank has anxiolytic effects comparable in Russian trials to medazepam18

  • human studySelank has cognitive-supportive nootropic activity18

  • human studySelank has measurable immunomodulation18

  • human studyRussian clinical data report anxiolytic activity in generalized anxiety disorder, with no sedation observed in the comparator-controlled trial22

  • human studyKozlovskaya et al. (2003) study showed 62% reduction in Hamilton Anxiety Rating Scale (HAM-A) scores with statistically significant improvement vs. placebo (p <0.01)25

  • human studyAnxiety disorder trial results showed onset of anxiolytic action within 3–5 days25

  • animalSingle intraperitoneal injection of Selank in an anxiolytic dose of 0.3 mg/kg reduced the total index of morphine withdrawal syndrome by 39.6%7

  • animalSelank significantly attenuated convulsive reactions, ptosis, and posture disorders in morphine-dependent rats7

  • animalSelank 0.3 mg/kg 9-fold increased the tactile sensitivity threshold in morphine-dependent rats7

  • animalSelank was slightly inferior to diazepam in a dose of 2 mg/kg by pharmacological activity in reducing morphine withdrawal syndrome7

  • animalIn animals exposed to social stress, there was a statistically significant increase in the level of IL-1β, IL-6 and TGF-β18

  • animalUnder stress conditions, there was a tendency to decrease the concentration of IL-4 and increase the level of TNF-α but these indicators were not statistically significant8

  • animalSelank reduces the concentration of IL-1β, IL-6 and TNF-α, as well as TGF-β1, practically reaching control values under social stress conditions8

  • animalInjection of Selank in all doses reduced the intensity of stress-induced degenerative changes9

  • animalAdministration of Selank in doses of 300 and 1000 μg/kg restored the nucleus/cytoplasm ratio in hepatocytes9

  • animalThe anxiolytic effect of Selank is comparable to that of classical benzodiazepine drugs12

  • animalAdministration of a course of test substances changed anxiety indicators toward their deterioration, but changes after Selank administration were less pronounced12

  • animalIn conditions of chronic stress, anxiety indicator values after simultaneous use of diazepam and Selank did not differ from values observed before chronic stress exposure12

  • animalTuftsin derivatives show anti-tumor activity13

  • animalTuftsin derivatives show anti-inflammatory activity13

  • animalTuftsin derivatives show antimicrobial activity13

  • animalTuftsin derivatives show anti-viral activity13

  • animalSelank monotherapy reduced experimentally elevated anxiety scores in rat unpredictable chronic mild stress paradigm24

  • animalDiazepam–Selank combination was more effective than either compound alone in chronic mild stress model in rats24

  • animalSelank normalized pathologically elevated BDNF in the hippocampus and prefrontal cortex while improving cognitive endpoints in ethanol-induced memory impairment model24

  • in vitroHeptapeptide Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) exhibits prolonged anti-anxiety and nootropic effects10

  • expert opinionSelank has anxiolytic effects within 30-60 minutes with sustained benefits over 7-14 days16

  • expert opinionSelank provides clinically meaningful anxiolysis through GABAergic modulation without the sedation, cognitive impairment, tolerance, or physical dependence associated with benzodiazepines16

  • expert opinionSelank compares favorably to benzodiazepines in head-to-head human studies17

  • expert opinionResearch suggests Selank can help us think more clearly, feel calmer, and enjoy a higher quality of life19

  • expert opinionClinical studies demonstrate Selank's efficacy in treating primary anxiety symptoms with significant reduction in Hamilton Anxiety Rating Scale scores20

  • expert opinionSelank shows potential benefits in treatment-resistant depression as adjunctive therapy and mood stabilization in bipolar spectrum disorders20

  • expert opinionPreclinical and clinical evidence supports Selank benefits in attention and concentration enhancement, learning capacity and information processing speed20

  • expert opinionResearch demonstrates Selank protective potential in age-related cognitive decline, post-stroke cognitive recovery, and traumatic brain injury rehabilitation20

  • expert opinionSelank is a synthetic heptapeptide approved in Russia for generalized anxiety disorder22

  • expert opinionDemonstrates anxiolytic effects comparable to benzodiazepines without sedation, cognitive impairment, or dependence liability26

How it works

Based on 3 human trial findings, 3 human study findings, 44 animal findings, 15 in vitro findings, 55 expert opinion findings and 9 theoretical findings.

  • human trialSelank affects whole-brain resting-state functional connectivity in healthy participants2

  • human trialSelank produces effects on functional connectivity between the right amygdala and regions in fusiform, inferior and middle temporal as well as parahippocampal gyri in the right hemisphere2

  • human trialSelank has specific effects on functional connectivity between the right amygdala and the right temporal cortex2

  • human studyPatients with GAD and neurasthenia had decreased levels of tau(1/2) leu-enkephalin1

  • human studyDecreased tau(1/2) leu-enkephalin was correlated with disease duration, severity of symptoms related to anxiety and asthenia and autonomic disorders1

  • human studyTreatment with selank increased tau(1/2) leu-enkephalin parameter, mostly in patients with GAD1

  • animalSelank administration resulted in significant changes in the expression of 45 genes 1 hour after administration in the frontal cortex of rats4

  • animalThree hours after Selank administration, 22 genes changed their expression in the frontal cortex of rats4

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  • animalOne of Selank's possible molecular mechanisms is associated with allosteric modulation of the GABAergic system4

  • animalSelank caused changes in the expression of genes involved in neurotransmission including major subunit of the GABA receptor, transporters, ion channels, dopamine, and serotonin receptors4

  • animalSelank and GABA affect the expression of genes involved in GABAergic neurotransmission5

  • animalSelank administration causes significant changes in the expression of genes involved in neurotransmission in rat frontal cortex5

  • animalExpression changes were observed in 45 genes 1 hour after Selank administration at 300 μg/kg in rats5

  • animalSelank allosterically modulates GABA-A receptor activity, altering the affinity of endogenous ligands for the receptor without directly binding to the benzodiazepine site6

  • animalSelank significantly altered expression of 45 of 84 examined neurotransmission-related genes in the rat frontal cortex at 1 hour post-administration, including GABA receptor subunits, transporters, and ion channels6

  • animalA single injection of selank activated 5-HT metabolism in the hypothalamus and caudal brain stem for 30 minutes to 2 hours6

  • animalSelank enhanced 5-HT metabolism in the brain stem within 30 minutes in rats with pharmacologically depleted serotonin6

  • animalSelank modulated serotonin and its metabolite 5-HIAA in a strain-dependent manner across hippocampus, hypothalamus, striatum, and frontal cortex6

  • animalIntranasal selank at 250 and 500 mcg/kg elevated BDNF mRNA in the rat hippocampus at 3 hours and BDNF protein at 24 hours post-administration6

  • animalSelank prevented ethanol-induced memory impairment through regulation of BDNF content in the hippocampus and prefrontal cortex6

  • animalStressful effects can enhance production of IL-1β, IL-6 and other cytokines8

  • animalSelank causes a decrease in the concentration of IL-1β and IL-6 under stress conditions8

  • animalSelank restores the level of IL-4 under stress conditions8

  • animalSelank suppresses the production of TGF-β1 and TNF-α under stress conditions8

  • animalChronic foot-shock stress induced hydropic degeneration of hepatocytes, an increase of the nucleus/cytoplasm ratio due to an increase in the area of nuclei and reduction of the cytoplasm area, the appearance of focal necroses, and lymphohistiocyte infiltration9

  • animalThe basis of the mechanism of action of Selank and benzodiazepines may be similar12

  • animalSelank and GABA showed significant changes in the expression of 45 genes 1 h after administration in the frontal cortex of rats14

  • animalThree hours after Selank or GABA administration, 22 genes changed their expression in rat frontal cortex14

  • animalPositive correlation was found between the changes in genes expression within 1 h after administration of Selank or GABA in rats14

  • animalSelank is characterized by complex effects on nerve cells, with one possible molecular mechanism associated with allosteric modulation of the GABAergic system14

  • animalSynthetic tuftsin analogue Selank and its fragments cause alterations in the expression of genes involved in inflammation in mouse spleen15

  • animalSelank causes a significant 3-fold decrease in C3 mRNA level 30 minutes after intraperitoneal injection15

  • animalGly-Pro (short fragment of Selank) causes similar 3-fold decrease in C3 mRNA level as Selank15

  • animalSelank injection produces wave-like alteration in Casp1 mRNA level15

  • animalSelank and Gly-Pro cause significant alteration in Il2rg gene mRNA level at early time points15

  • animalSelank and its fragment cause almost equal reduction in Xcr1 mRNA level 90 minutes after administration15

  • animalSelank and Gly-Pro influence expression of genes that mediate different types of immune responses to maintain immune system balance15

  • animalGly-Pro dipeptide contributes actively to the final effect of Selank15

  • animalElectrophysiological studies show enhanced inhibitory postsynaptic currents in hippocampal neurons after Selank exposure, blocked by bicuculline but insensitive to flumazenil18

  • animalRodent studies report increased 5-hydroxyindoleacetic acid (5-HIAA) to serotonin ratios in the hypothalamus and striatum, suggesting accelerated serotonin turnover18

  • animalSingle intranasal doses of Selank produce measurable upregulation of BDNF and NGF messenger RNA in the hippocampus within hours18

  • animalSelank produces differential expression of hundreds of genes involved in neuronal plasticity and inflammation18

  • animalSelank inhibits enkephalin-degrading enzymes, prolonging the half-life of endogenous enkephalins18

  • animalA 2016 rat study analyzed 84 neurotransmission-related genes in rat frontal cortex following a 300 μg/kg dose of selank, with 45 of the 84 genes showing significant expression changes at 1 hour post-administration and 22 at 3 hours22

  • animalA single intraperitoneal dose of selank (0.3 mg/kg) attenuated aversive signs of naloxone-precipitated morphine withdrawal in outbred rats, reducing the total withdrawal index by approximately 39.6%22

  • animalSelank's effect level against withdrawal was comparable to diazepam 2 mg/kg22

  • animalIntraperitoneal Selank administration in BALB/c mice altered the expression of multiple genes involved in GABAergic neurotransmission in frontal cortex tissue24

  • animalSelank restored serotonin metabolism in the brainstem within 30 minutes of administration in rats pretreated with PCPA24

  • animalIntranasal Selank elevated BDNF mRNA in rat hippocampus at 3 hours post-administration and BDNF protein at 24 hours24

  • animalA 2016 study in Acta Naturae demonstrated that Selank administration increased BDNF mRNA levels by approximately 30–40% in rat hippocampal tissue, with effects sustained over the 7-day observation period25

  • in vitroSelank dose-dependently inhibits the enzymatic hydrolysis of enkephalins in human serum with an IC50 of approximately 15-20 microM6

  • in vitroOnly the heptapeptide and its pentapeptide fragments of selank showed enkephalinase inhibitory effect; smaller fragments did not6

  • in vitroSelank affects the [3H]GABA binding as a positive allosteric modulator10

  • in vitroThe joint action of Selank and some of benzodiazepines regulates activity of [3H]GABA binding in specific manner, which is not cumulative and differs from either substance individually10

  • in vitroSelank is able to block the modulatory activity of Diazepam and Olanzapine, the location of their and peptide binding sites apparently not the same, but potentially may partially overlaps10

  • in vitroSelank anti-anxiety molecular mechanisms can be associated with subtype selective concentration-dependent allosteric modulation of GABA receptors10

  • in vitroSelank has no direct effect on the mRNA levels of the GABAergic system genes in neuroblastoma IMR-32 cells11

  • in vitroThe combined effect of GABA and Selank led to nearly complete suppression of changes in expression of genes in which mRNA levels changed under the effect of GABA11

  • in vitroWhen Selank was used in conjunction with olanzapine, the expression alterations of more genes were observed compared with olanzapine alone11

  • in vitroSelank may enhance the effect of olanzapine on the expression of the genes studied11

  • in vitroTuftsin fragment is biologically active on macrophages and neutrophils18

  • in vitroHuman leukocyte cultures exposed to Selank show cytokine shifts including induction of type I and type II interferons18

  • in vitroSelank acts as a positive allosteric modulator of GABA binding at GABA-A receptors without directly engaging the benzodiazepine site22

  • in vitroSelank in IMR-32 human neuroblastoma cells modulated expression of GABAergic-pathway genes, with effects most pronounced on GABA receptor subunit transcripts24

  • in vitroMeasured enkephalinase inhibition IC50 ~15 uM26

  • expert opinionSelank has nootropic and anxiolytic effects acting on brain cells1

  • expert opinionSelank has significant antiviral effects1

  • expert opinionSelank is a synthetic analogue of a short fragment of the human immunoglobulin G heavy chain1

  • expert opinionSelank is a synthetic analog of the endogenous tuftsin molecule (the short Thr-Lys-Pro-Arg fragment of the human immunoglobulin G heavy chain), which was elongated at the C terminus via the addition of three natural L-amino acids (Pro-Gly-Pro) to improve its metabolic stability and yield a relatively longer duration4

  • expert opinionSelank was designed by extending the naturally occurring immunomodulatory tetrapeptide tuftsin with a C-terminal Pro-Gly-Pro tripeptide to improve metabolic stability and duration of action6

  • expert opinionTuftsin (TKPA) is an immunomodulator designed to regulate the immune response of the organism against infections of varying etiology13

  • expert opinionSelank is a synthetic analog of the endogenous immunomodulatory peptide tuftsin (Thr-Lys-Pro-Arg) with an added Pro-Gly-Pro sequence conferring enzymatic stability16

  • expert opinionSelank enhances GABAergic signaling through allosteric GABA-A modulation without direct benzodiazepine-site binding16

  • expert opinionSelank increases serotonin metabolism and turnover in key brain regions (hippocampus, frontal cortex, hypothalamus)16

  • expert opinionSelank robustly upregulates brain-derived neurotrophic factor (BDNF) expression, supporting neuroplasticity16

  • expert opinionSelank modulates IL-6, IFN-gamma, and T-helper (Th1/Th2) cytokine balance16

  • expert opinionSelank influences enkephalin degradation via inhibition of enkephalinase (neprilysin)16

  • expert opinionSelank is a synthetic heptapeptide derived from Tuftsin17

  • expert opinionSelank modulates GABA, glutamate, opioid, and monoamine systems to reduce anxiety17

  • expert opinionSelank has immunomodulatory and Tuftsin-derived properties17

  • expert opinionSelank has immunomodulatory, anti-inflammatory, and antiviral mechanisms17

  • expert opinionSelank is a synthetic heptapeptide consisting of seven amino acids (Thr-Lys-Pro-Arg-Pro-Gly-Pro) derived from the naturally occurring immunoregulatory peptide tuftsin20

  • expert opinionSelank represents a metabolically stable analog of the tuftsin tetrapeptide (Thr-Lys-Pro-Arg) found in human immunoglobulin G heavy chains20

  • expert opinionSelank exhibits remarkable stability compared to its endogenous counterpart and maintains bioactivity through modulation of GABAergic, dopaminergic, and serotonergic neurotransmitter systems20

  • expert opinionSelank demonstrates no sequence homology with other known anxiolytic compounds20

  • expert opinionSelank acts as a positive allosteric modulator of GABA-A receptors, leading to enhanced inhibitory neurotransmission and anxiolytic effects similar to benzodiazepines without sedation or dependence20

  • expert opinionThe peptide influences neurotransmitter systems through upregulation of serotonin metabolism in the brainstem and modulation of dopamine and norepinephrine concentrations20

  • expert opinionSelank promotes rapid elevation of brain-derived neurotrophic factor (BDNF) expression in the hippocampus20

  • expert opinionThe peptide demonstrates protective effects on endogenous opioid systems through inhibition of enkephalin-degrading enzymes in plasma and prolongation of enkephalin half-life20

  • expert opinionIt modulates serotonin, BDNF, and enkephalin systems to reduce anxiety and enhance cognition without sedation21

  • expert opinionDeveloped in the 1990s at the Institute of Molecular Genetics of the Russian Academy of Sciences, it was engineered by extending the naturally occurring immune peptide tuftsin with a C-terminal Pro-Gly-Pro tripeptide to improve metabolic stability21

  • expert opinionSelank administration rapidly alters the expression of genes involved in GABAergic neurotransmission, including genes encoding GABA-A receptor subunits21

  • expert opinionThe peptide appears to allosterically modulate GABA-A receptors in a manner pharmacologically similar to benzodiazepines, enhancing inhibitory neurotransmission to reduce anxiety, but without directly binding the benzodiazepine site21

  • expert opinionSelank enhances GABA-A sensitivity rather than replacing the endogenous signal, distinguishing it from benzodiazepines which bind directly to the receptor22

  • expert opinionSelank modulates enkephalin and BDNF expression22

  • expert opinionSelank is a synthetic seven-amino-acid peptide, a stabilized copy of the natural immune fragment tuftsin with a Pro-Gly-Pro tail23

  • expert opinionSelank is a linear seven-residue peptide with the sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro23

  • expert opinionMolecular formula is C₃₃H₅₇N₁₁O₉, molecular weight about 752 daltons, CAS number 129954-34-3, PubChem CID 1176560023

  • expert opinionSelank ends in a free carboxylic acid, not an amide23

  • expert opinionThe first four residues are tuftsin, a natural tetrapeptide discovered in 197023

  • expert opinionTuftsin is cleaved from the heavy chain of immunoglobulin G and its documented activity is immune: it stimulates the phagocytic cells that engulf pathogens23

  • expert opinionThe Pro-Gly-Pro tail makes the peptide far more resistant to the enzymes that would otherwise degrade it23

  • expert opinionWith three of its seven residues being proline, most of the internal bonds are ones common proteases cannot cut23

  • expert opinionSelank has reported effects on GABAergic neurotransmission, monoamine turnover, and brain-derived neurotrophic factor (BDNF) expression24

  • expert opinionSelank was designed as a synthetic analog of tuftsin, the endogenous tetrapeptide Thr-Lys-Pro-Arg24

  • expert opinionSelank is described as a positive allosteric modulator of GABA-A receptor function24

  • expert opinionSelank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is a synthetic heptapeptide derived from the immunomodulatory protein tuftsin25

  • expert opinionSelank modulates GABA transmission through indirect mechanisms including enhancement of GABA synthesis, modulation of GABA receptor sensitivity, and regulation of GABAergic interneuron activity25

  • expert opinionSelank produces anxiolysis without the sedation, amnesia, motor impairment, and dependence liability characteristic of direct GABA-A modulators25

  • expert opinionSelank inhibits enkephalin-degrading enzymes, particularly enkephalinases, extending the half-life of endogenous enkephalin peptides25

  • expert opinionSelank modulates serotonin, dopamine, and norepinephrine metabolism25

  • expert opinionMicroarray studies have revealed that Selank influences the expression of over 40 genes in the brain25

  • expert opinionSynthetic heptapeptide derived from the immunomodulatory peptide tuftsin26

  • expert opinionModulates gene expression of GABA-A receptor subunits, enhancing inhibitory neurotransmission26

  • expert opinionInhibits enzymes that degrade enkephalins26

  • expert opinionIncreases brain-derived neurotrophic factor in the hippocampus and frontal cortex26

  • expert opinionModulates 5-HT1A and 5-HT2A receptor expression26

  • expert opinionC-terminal Pro-Gly-Pro extension confers CNS activity and enhanced stability26

  • expert opinionWorks primarily through gene expression modulation, producing sustained effects without tolerance or dependence26

  • expert opinionSelank is a neuroactive peptide that enhances brain-derived neurotrophic factor and HGF/c-Met pathways critical to neuroplasticity27

  • theoreticalSelank can enhance the inhibitory effect of GABA by allosteric modulation of GABA receptors11

  • theoreticalThe molecular mechanism of the effect of Selank may be related to its ability to affect the performance of the GABAergic system11

  • theoreticalSelank may affect the interaction of GABA with GABA receptors11

  • theoreticalTuftsin can serve as carriers of biologically active substances13

  • theoreticalSelank sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP), extending the natural tetrapeptide Tuftsin with a stabilising Pro-Gly-Pro tail18

  • theoreticalThe Pro-Gly-Pro tail in Selank shielding it from peptidase degradation18

  • theoreticalThe Pro-Gly-Pro tail improves blood-brain-barrier permeability18

  • theoreticalSelank does not bind the benzodiazepine site on the GABA-A receptor but acts as a positive allosteric modulator through a distinct site18

  • theoreticalSelank produces GABAergic tone without the classical benzodiazepine profile of sedation, amnesia, and tolerance18

Dosing

Based on 2 animal findings and 7 expert opinion findings.

  • animalSelank was injected intraperitoneally in doses of 100, 300 and 1000 μg/kg 15 min before each stress session9

  • animalThe maximum stress-limiting effect was attained after administration of 300 μg/kg Selank9

  • expert opinionTypical intranasal dose is 250-500 mcg per nostril, 2-3 times daily; subcutaneous dose is 250-750 mcg daily16

  • expert opinionTypical cycle duration is 14-21 days per course with repeat after 1-2 week interval16

  • expert opinionIntranasal and subcutaneous are the available forms of Selank17

  • expert opinionCycling strategies are important for Selank to maximize benefit and minimize risk17

  • expert opinionSelank is delivered intranasally rather than orally18

  • expert opinionPrimarily administered intranasally21

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  • expert opiniontypically in 14-day treatment courses21

How the body handles it

Based on 5 expert opinion findings and 1 theoretical finding.

  • expert opinionThe peptide is metabolized rapidly in the liver and eliminated through renal excretion, with complete clearance from circulation within 10 minutes post-administration20

  • expert opinionreaches the central nervous system within minutes of intranasal administration21

  • expert opiniontuftsin itself proved impractical as a therapeutic agent due to rapid enzymatic degradation, with a plasma half-life measured in seconds21

  • expert opinionThe Pro-Gly-Pro tail extends biological half-life and supports activity after intranasal administration24

  • expert opinionSelank is administered primarily via intranasal delivery, which provides direct access to the CNS through the olfactory and trigeminal nerve pathways, bypassing first-pass hepatic metabolism and achieving brain bioavailability within minutes25

  • theoreticalTuftsin on its own has a plasma half-life measured in seconds18

Safety and side effects

Based on 2 human study findings and 7 expert opinion findings.

  • human studyThe effect of Selank is similar to that of tranquilizers at low doses, but is not accompanied by the unwanted side effects of benzodiazepine tranquilizers such as amnesia, withdrawal, and dependence4

  • human studyAnxiety trials showed no sedation, cognitive impairment, or withdrawal symptoms25

  • expert opinionSelank likely avoids tolerance and dependence unlike benzodiazepines17

  • expert opinionInjectable Selank is not FDA-approved for human use17

  • expert opinionThe intranasal form of Selank is approved in Russia but not the US or EU17

  • expert opinionLong-term safety data for Selank is limited17

  • expert opinionSelank is not approved for human use in the European Union or the United States18

  • expert opinionSelank is not FDA-approved for any indication in the United States22

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  • expert opinionAs of April 2026, selank is classified as an FDA Category 2 bulk drug substance22

What people use it for

Based on 2 human trial findings, 7 animal findings, 16 expert opinion findings and 1 theoretical finding.

  • human trialSelank is an anxiolytic peptide2

  • human trialSelank is effective as add-on therapy to benzodiazepine tranquilizers in treatment of anxiety-spectrum disorders3

  • animalSelank has pronounced anxiolytic activity and acts as a stable neuropsychotropic, antidepressant, and antistress drug that relieves aggression and fear reaction in different animal species4

  • animalSelank has nootropic action, which positively influences the formation of memory and learning processes4

  • animalSelank has marked immunomodulatory activity4

  • animalSelank, like diazepam, weakens the aversive signs of morphine withdrawal in rats with opiate dependence7

  • animalSelank glyprolin neuropeptide drug has stress-protective activity8

  • animalIndividual administration of Selank was most effective in reducing elevated anxiety induced by administration of a course of test substances12

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  • animalCombination of diazepam with Selank was most effective in reducing anxiety in unpredictable chronic mild stress conditions12

  • expert opinionSelank was registered by the Russian Federation Ministry of Health in 2009 and approved for medical use as an anxiolytic and nootropic drug6

  • expert opinionSelank is indicated for the treatment of generalized anxiety disorder (GAD) and neurasthenia in Russia and Ukraine6

  • expert opinionTuftsin-based peptides are contained in vaccines13

  • expert opinionSelank is approved in Russia since 2009 as an intranasal anxiolytic and nootropic medication16

  • expert opinionSelank has cognitive performance, memory, and nootropic effects17

  • expert opinionSelank provides benefits for depression, adjustment disorder, pain, stroke recovery, and gut health17

  • expert opinionIn Russia Selank is registered as Selank 0.15 percent nasal drops for generalised anxiety disorder and neurasthenia18

  • expert opinionSelank is a therapeutic peptide developed in Russia and used there for its potential nootropic, anxiolytic, and immunomodulatory benefits19

  • expert opinionSelank is a synthetic heptapeptide derived from tuftsin, developed in Russia as an anxiolytic and nootropic21

  • expert opinionmarketed as a 0.15% nasal spray solution for the treatment of generalized anxiety disorder (GAD)21

  • expert opinionSelank is a registered medicine in Russia23

  • expert opinionThe Russian medicine is a nasal spray, while the vial sold to researchers in the West is an injection, a different route than any of the published evidence describes23

  • expert opinionRussia's Ministry of Health registered it in 2009 as an intranasal solution for generalized anxiety disorder23

  • expert opinionIt is not approved by the FDA or any other Western regulator23

  • expert opinionEvery Russian study used the nose, while the product sold for research in the West is injected23

  • expert opinionDeveloped by Russian researchers and approved in Russia since 2009 for anxiety and neurasthenia26

  • theoreticalTuftsin can be used to prepare fusion proteins in the treatment of cancer13

Other findings

Based on 12 expert opinion findings and 1 theoretical finding.

  • expert opinionSelank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is a synthetic heptapeptide developed in the late 1990s at the Institute of Molecular Genetics of the Russian Academy of Sciences6

  • expert opinionSelank has been approved in Russia since 2009 and made over-the-counter in 201717

  • expert opinionSelank is a synthetic heptapeptide developed in the 1990s at the Institute of Molecular Genetics of the Russian Academy of Sciences18

  • expert opinionSelank is supplied as a lyophilised white powder in 10 mg glass vials at ≥99 percent purity by HPLC18

  • expert opinionMuch of the research on Selank is in Russian, not English, so scientific literature about its effects and mechanisms can be challenging to find19

  • expert opinionOriginally developed at the Institute of Molecular Genetics of the Russian Academy of Sciences in cooperation with the V.V. Zakusov Research Institute of Pharmacology20

  • expert opinionApproved in Russia as a prescription anxiolytic; not FDA-approved in the US21

  • expert opinionSelank (TP-7) is a synthetic heptapeptide with the amino acid sequence Thr-Lys-Pro-Arg-Pro-Gly-Pro and a molecular weight of 751.9 Da21

Show the remaining 5

  • expert opinionSelank was approved by the Russian Federation Ministry of Health in 2009 and is available by prescription in Russia under the brand name Selanc21

  • expert opinionIt was designed at the Institute of Molecular Genetics in Moscow23

  • expert opinionThe research below was conducted in rat models, in vitro systems, and small Russian clinical studies of an intranasal drug product23

  • expert opinionSelank is a synthetic heptapeptide developed at the Institute of Molecular Genetics of the Russian Academy of Sciences24

  • theoreticalSelank has molecular formula C33H57N11O9 with molecular weight 751.90 g/mol and CAS registry number 129954-34-318

Points of contention

Where the evidence is unsettled, thin, or says less than the popular claim — worth knowing before you draw conclusions.

Limited evidence

Most mechanistic evidence is from animal, in vitro and small Russian studies, not large human trials

Reference sites and reviews note the research was conducted in rat models, in vitro systems, and small Russian clinical studies; the largest cited human trial had 62 patients and the fMRI study 52 healthy participants. Long-term safety data is described as limited.

Contested

Reported clearance/half-life figures vary across sources

Tier-2/3 sites give a plasma half-life of approximately 2-3 minutes with complete clearance within 10 minutes (Selank: Research Evidence & Safety Profile | PeptideInsight, Selank Peptide | Calm & Cognitive Support), while other sources describe the parent peptide half-life only as 'several minutes' or 'measured in seconds' for tuftsin (Selank (TP-7) - Clinical Monograph | Anxiolytic Nootropic Peptide Guide | PeptidePrescriber, Selank Dosing Guide: Intranasal Research Protocols, Selank Peptide: Anxiolytic Nootropic From Tuftsin). Biological effects are variously reported to persist 3-6 hours.

Other

Route sold to Western researchers differs from all published evidence

A vendor site notes the Russian approved product is an intranasal 0.15% nasal spray/drops, matching all published Russian studies, whereas the vial sold for research in the West is an injectable — a route not covered by the published evidence.

Single source

FDA Category 2 classification reported by only one source with a future date

Only one tier-3 guide states that 'as of April 2026' selank is classified as an FDA Category 2 bulk drug substance; no other source corroborates this and the date is prospective.

Single source

Specific BDNF and HAM-A percentages come from single tier-3 sources

The 30-40% BDNF mRNA increase (citing a 2016 Acta Naturae study) and the 62% HAM-A reduction with p<0.01 (citing Kozlovskaya 2003) each appear in only one tier-3 review, not corroborated by the primary tier-1/2 sources.

Using it with other compounds

Check a stack
  • SemaxComplementary

    May be complementary

    Selank and Semax are sister Russian regulatory peptides that both raise BDNF/NGF and both inhibit enkephalinase (extending your own opioid peptides), yet they push in different directions: Selank is calming/anxiolytic while Semax is stimulating and pro-attention. Stacked, one tends to smooth out the over-activation of the other, which is why they are a widely used nootropic pairing.

    Tier 3Largely anecdotal — commonly discussed

    What the research doesn't fully establish

    The mechanism descriptions clearly establish all three claimed shared dimensions: (1) dopaminergic_system—both peptides explicitly modulate serotonergic and dopaminergic pathways; (2) anti_inflammatory—both are tagged anti_inflammatory and target immune/cytokine signaling (Selank via Th1-Th2 and interferon, Semax via interferon and antigen-presentation); (3) BDNF_signaling—both are tagged BDNF_signaling and upregulate BDNF/NGF (Selank via BDNF/NGF signaling, Semax via BDNF/NGF-TrkB neurotrophin signaling). The proposed complementarity is also mechanistically justified: Selank targets GABA-A (allosteric, anxiolytic) and 5-HT1A/2A (calming), while Semax targets TrkB and melanocortin receptors with attention/stimulation effects. Both inhibit enkephalinase, supporting the shared opioid-peptide extension claim. The sister-peptide pairing and opposing functional profiles (calming vs. stimulating) while sharing core neurotrophin and immune pathways align with the complementary relationship type.

    Timing Often dosed together in the daytime; if Semax feels over-stimulating, take Selank alongside or shortly after.

    Shares dopaminergic system · anti inflammatory · BDNF signaling

  • ThymulinComplementary

    Worth caution

    Selank is built from tuftsin, an immune-signaling antibody fragment, and shares T-cell/cytokine-balancing and anti-inflammatory activity with thymulin. They modulate immunity through different mechanisms (thymic-hormone maturation vs. tuftsin-like Th1/Th2 balancing), so they can complement each other in immune normalization.

    Tier 4Theoretical — not established

    What the research doesn't fully establish

    Both peptides' mechanisms clearly establish the claimed shared dimensions. Selank explicitly targets T_cell_regulation (approved tag) and anti_inflammatory (approved tag) via Th1-Th2 balancing and cytokine signaling. Thymulin explicitly targets T_cell_regulation (approved tag) and anti_inflammatory (approved tag) via T-lymphocyte maturation, CD4/CD8 modulation, and cytokine network suppression. The proposed relationship correctly identifies that they operate through distinct mechanistic pathways (thymic hormone maturation vs. tuftsin-derived immune signaling) while both converging on immune normalization endpoints. This mechanistic distinction without target overlap supports the complementary relationship claim.

    Shares T cell regulation · anti inflammatory

  • VilonComplementary

    No documented conflict

    Selank (a tuftsin-derived peptide) carries immunomodulatory and Th1/Th2-balancing activity alongside its main anxiolytic/nootropic role. That immune-modulating side overlaps with Vilon's T-cell and cytokine effects, so the two can complement each other where both immune support and CNS/stress effects are desired.

    Tier 4Theoretical — not established

    What the research doesn't fully establish

    Both peptides' mechanisms clearly establish the claimed shared dimensions. Vilon demonstrates T_cell_regulation (stimulation of thymus tissue growth, immune cell differentiation, improved CD4/CD8 ratio, reactivation of age-silenced genes in aged lymphocytes) and anti_inflammatory effects (IL-1β/IL-6/TNF-α cytokine suppression, IL-2 upregulation). Selank demonstrates T_cell_regulation (Th1-Th2 balancing via cytokine/interferon signaling) and anti_inflammatory activity (approved tags include both). The proposed complementary relationship is justified: Vilon operates primarily through gene-promoter DNA binding and chromatin remodeling to modulate immune function, while Selank operates through receptor-mediated pathways (GABA-A, serotonin, enkephalinase) with immune modulation as a secondary effect. Their distinct mechanisms of action supporting overlapping immune outcomes (T-cell regulation and anti-inflammatory effects) logically support a complementary rather than redundant relationship.

    Shares anti inflammatory · T cell regulation

  • DSIPComplementary

    Worth caution

    Both peptides calm the nervous system through overlapping routes: DSIP enhances GABA-A currents and releases enkephalins, while Selank is an anxiolytic that positively modulates GABA-A signaling and boosts enkephalins by inhibiting enkephalinase (neprilysin). Their shared GABA and enkephalin actions make this a plausible anxiolytic/sleep-support pairing, though the combined sedative/calming effect should be monitored.

    Tier 4Theoretical — not established

    What the research doesn't fully establish

    Both peptides' mechanisms clearly establish GABA_signaling as a shared dimension. DSIP is described as enhancing GABA-A receptor functional currents (without direct binding) and increasing GABAergic tone in the ventrolateral preoptic nucleus. Selank is explicitly described as producing allosteric modulation of GABA-A receptors (positive modulation). Both also converge on enkephalin system enhancement—DSIP via direct Met-enkephalin release, Selank via enkephalinase inhibition. The proposed 'complementary' relationship type is justified: the mechanisms show overlapping anxiolytic and GABAergic pathways that would plausibly combine without direct antagonism. The explanation accurately reflects the provided mechanism material.

    Timing DSIP is best taken before bed for sleep; Selank is often used earlier in the day for daytime anxiety, so consider separating them to avoid excess sedation.

    Shares GABA signaling

  • PidotimodComplementary

    No documented conflict

    Selank is derived from tuftsin, an immune-signaling antibody fragment, and has reported immunomodulatory and Th1/Th2-balancing effects alongside its nootropic action. This overlaps with pidotimod's T-cell/cytokine tuning, so they share an immune-regulation dimension; the combination is plausible but the immune contribution of Selank is secondary to its CNS effects.

    Tier 4Theoretical — not established

    What the research doesn't fully establish

    Both peptides' mechanisms explicitly include T_cell_regulation in their approved tags. Pidotimod directly targets TLR-2/TLR-7, HLA-DR, and CD83/CD86 to drive Th1 differentiation and T-lymphocyte proliferation. Selank's mechanism includes 'Th1-Th2 and interferon signaling' pathways and carries the T_cell_regulation tag. Both are tagged anti_inflammatory. The proposed relationship correctly identifies these as shared dimensions: T-cell regulation (explicit in both) and anti-inflammatory effects (both tagged). The explanation accurately characterizes Selank's immune contribution as secondary to CNS effects while still present, which aligns with the mechanism material showing immunomodulatory effects alongside dopaminergic/GABAergic/BDNF actions. The 'complementary' relationship type is justified—they approach immune regulation through different primary mechanisms (innate/adaptive immunity vs. neuroimmune modulation) but converge on shared T-cell and anti-inflammatory dimensions.

    Shares anti inflammatory · T cell regulation

  • ImunofanComplementary

    No documented conflict

    Selank (a tuftsin analog) has immunomodulatory and Th1/Th2-balancing, anti-inflammatory effects alongside its main anxiolytic/nootropic role. Its immune actions run parallel to imunofan's without sharing the same receptor, so the two could complement each other where mild immune modulation plus CNS support is the goal.

    Tier 4Theoretical — not established

    What the research doesn't fully establish

    Both peptides' mechanisms clearly support anti-inflammatory and T_cell_regulation dimensions. Imunofan targets thymopoietin receptors and modulates Th1/Th2 balance with explicit TNF/IL-6 reduction and CD4/CD8 normalization. Selank targets GABAergic and serotonergic systems but its mechanisms include Th1-Th2 and interferon signaling pathways, plus immunomodulatory effects. The proposed relationship correctly identifies that they operate through distinct receptor systems (thymopoietin vs. GABA/5-HT/enkephalin) while both producing anti-inflammatory and T-cell regulatory outcomes. This non-overlapping receptor profile with parallel functional endpoints is a valid basis for calling them complementary rather than redundant. The explanation accurately reflects the mechanism material provided.

    Shares anti inflammatory · T cell regulation

  • CerebrolysinComplementary

    No documented conflict

    Selank supports BDNF signaling, modulates monoamines and adds GABAergic anxiolytic tone plus immunomodulation, complementing Cerebrolysin's neurotrophic and anti-inflammatory profile. A reasonable nootropic/anxiolytic pairing, though only anecdotally documented together.

    Tier 4Theoretical — not established

    What the research doesn't fully establish

    The mechanism descriptions clearly establish all three claimed shared dimensions: (1) dopaminergic_system—both peptides modulate dopamine (Cerebrolysin via kinase inhibition affecting dopaminergic system; Selank via dopamine receptor modulation and monoamine metabolism); (2) anti_inflammatory—both are tagged with anti_inflammatory effects (Cerebrolysin via TNF-α downregulation and microglia modulation; Selank via immunomodulatory and cytokine signaling); (3) BDNF_signaling—both explicitly upregulate or support BDNF (Cerebrolysin via BDNF upregulation pathway; Selank via BDNF signaling pathway). The explanation correctly identifies complementary mechanisms: Cerebrolysin provides broad neurotrophic/neuroprotective effects while Selank adds GABAergic anxiolytic tone and enkephalinase inhibition. The proposed relationship type (complementary) is justified by the distinct but non-overlapping primary mechanisms (Cerebrolysin's TrkA/TrkB targeting vs. Selank's GABA-A modulation) combined with shared downstream effects on the three dimensions. The caveat about anecdotal documentation does not undermine the mechanistic support.

    Shares dopaminergic system · anti inflammatory · BDNF signaling

  • NoopeptComplementary

    May be complementary

    Selank and Noopept both engage BDNF signaling and both report anxiolytic plus nootropic effects, but through distinct mechanisms — Selank via GABAergic/serotonergic modulation and enkephalinase inhibition, Noopept via AMPA/TrkB neurotrophic pathways. Their overlapping calming-plus-cognitive profiles are complementary and this combination is a well-known real-world nootropic pairing.

    Tier 4Theoretical — not established

    What the research doesn't fully establish

    The mechanism descriptions clearly establish both shared dimensions: (1) BDNF_signaling is explicitly listed in approved tags for both peptides, and both pathways sections reference BDNF/NGF neurotrophin signaling; (2) anti_inflammatory is explicitly approved for both. The explanation correctly identifies distinct mechanistic routes—Selank via GABAergic/serotonergic/enkephalinase pathways versus Noopept via AMPA/TrkB/HIF-1 pathways—that converge on overlapping anxiolytic and nootropic effects. This constitutes a valid complementary relationship: shared functional outcomes (anxiety reduction, cognitive support) achieved through non-overlapping molecular mechanisms, with both engaging the claimed shared dimensions. The distinction between mechanisms supports rather than undermines complementarity.

    Shares anti inflammatory · BDNF signaling

  • CortexinComplementary

    May be complementary

    Both influence GABAergic tone and neurotransmitter balance and support BDNF signaling, but by different routes — Cortexin protects against glutamate excitotoxicity and Selank adds anxiolytic GABA-A/serotonergic modulation plus enkephalinase inhibition. Together they cover both the neuroprotective and the calm/anxiolytic side of brain function.

    Tier 4Theoretical — not established

    What the research doesn't fully establish

    The mechanisms clearly establish the four shared dimensions: (1) GABA_signaling—both target GABA-A receptor (Cortexin: direct modulation via multiple glutamate receptors and GABAergic effects; Selank: allosteric modulation); (2) BDNF_signaling—both explicitly list BDNF-like/NGF-like neurotrophic signaling and BDNF signaling in their pathways; (3) dopaminergic_system—both include dopaminergic neurotransmitter balance/modulation in their mechanisms; (4) anti_inflammatory—both have anti-inflammatory effects listed. The complementary relationship is justified: Cortexin acts primarily through glutamate receptor modulation, caspase inhibition, and antioxidant/neuroprotective mechanisms, while Selank acts through serotonergic (5-HT1A/2A) and enkephalinergic pathways with allosteric GABA-A modulation. The explanation accurately reflects that they converge on shared neurotransmitter systems (GABA, dopamine, BDNF) but via distinct mechanistic routes—one emphasizing excitotoxicity protection and the other anxiolytic/serotonergic modulation—making them genuinely complementary rather than redundant.

    Shares dopaminergic system · anti inflammatory · GABA signaling · BDNF signaling

  • P21Same downstream effect

    No documented conflict

    Selank supports BDNF (and NGF) signaling alongside its anxiolytic/nootropic actions, overlapping with the BDNF/TrkB pathway P21 activates. Coming from different upstream mechanisms and converging on BDNF-mediated plasticity, they are plausibly complementary for cognition and mood support.

    Tier 4Theoretical — not established

    What the research doesn't fully establish

    Both peptides' mechanisms explicitly include BDNF signaling as a pathway. P21 directly targets TrkB receptor via induced BDNF and lists BDNF/TrkB as a core pathway with approved tag BDNF_signaling. Selank lists BDNF signaling as an explicit pathway and carries the same BDNF_signaling approved tag. The proposed relationship correctly identifies that despite different upstream mechanisms (P21 via CNTF-mimicry and TrkB activation; Selank via GABAergic, serotonergic, and enkephalinase pathways), both converge on BDNF-mediated signaling. The explanation accurately characterizes this as downstream convergence on a shared dimension (BDNF signaling) that supports neuroplasticity-related effects. The mechanism descriptions fully justify the same_downstream relationship type and the BDNF_signaling shared dimension claim.

    Shares BDNF signaling

Safety and side effects

Reported Safety Profile

A review states Selank's effect is similar to that of low-dose tranquilizers but is not accompanied by benzodiazepine side effects such as amnesia, withdrawal and dependence (src-2). A Tier-3 reference site states it works primarily through gene-expression modulation producing sustained effects without tolerance or dependence (src-3), and a Tier-3 review citing Kozlovskaya (2003) reports no sedation, cognitive impairment or withdrawal symptoms (src-5). In the phenazepam combination trial, adding Selank was reported to decrease the tranquilizer's side effects both during treatment and after withdrawal (src-30). A guide states Russian clinical data report anxiolytic activity in GAD with no sedation observed in the comparator-controlled trial (src-13).

Important Limitations

  • Limited long-term data. A podcast and reference sites note that long-term safety data is limited and that much of the research is in Russian and difficult to access (src-14, src-15, src-60).
  • Route mismatch. A vendor site notes the Russian medicine is a nasal spray while the vial sold to Western researchers is an injection — a different route than any published evidence describes (src-8, src-35).
  • Not approved in the West. Vendor and dosing sources state Selank is not approved by the FDA or any other Western regulator and is not approved for human use in the EU or US (src-8, src-41). One Tier-3 guide states that 'as of April 2026' it is classified as an FDA Category 2 bulk drug substance — a single, prospective claim not corroborated elsewhere (src-46).

This section reports what the sources describe and is not medical advice.

Reconstitution and handling

Formulation

A dosing guide states Selank is supplied to Western researchers as a lyophilised white powder in 10 mg glass vials at ≥99% purity by HPLC (src-11). In Russia the approved product is an entirely different presentation: a 0.15% intranasal solution / nasal drops (Selank/Selanc), which is the form used in all published Russian studies (src-4, src-13, src-41, src-45). A vendor site flags that the injectable vial sold for research in the West does not match the intranasal route of the published evidence (src-8, src-35).

Dosing

No dose has been established for this compound outside of Russia's national approval. There is no FDA/EMA label; the figures below are what sources report, not guidance.

  • The Russian approved product is a 0.15% intranasal solution indicated for GAD and neurasthenia, typically given in 14-day treatment courses (src-4, src-45).
  • A practitioner protocol suggests intranasal dosing of 250-500 mcg per nostril, 2-3 times daily; subcutaneous dosing of 250-750 mcg daily; and cycle duration of 14-21 days per course, repeated after a 1-2 week interval (src-7). The subcutaneous route is not covered by the published evidence.
  • Practitioner and reference sources describe onset of anxiolytic effect within 30-60 minutes, with biological effects reported to persist 3-6 hours and sustained benefits over 7-14 days (src-7, src-33).

Delivery and Pharmacokinetics

Review sites state Selank is administered primarily via intranasal delivery, providing direct CNS access through olfactory and trigeminal nerve pathways, bypassing first-pass hepatic metabolism and achieving brain bioavailability within minutes (src-5, src-24). Reference sites report a plasma half-life of approximately 2-3 minutes with complete clearance within 10 minutes (src-4, src-9), while other sources describe the parent-peptide half-life only as 'several minutes' (src-7) — with the Pro-Gly-Pro tail said to shield the peptide from peptidase degradation and improve blood-brain-barrier permeability (tuftsin alone has a half-life measured in seconds) (src-11, src-12, src-42). A sports-medicine site adds that Selank is metabolized rapidly in the liver and eliminated renally (src-9).

Reconstitution arithmetic depends on the vial: for a 10 mg powder vial, adding 2 mL of bacteriostatic water yields 5 mg/mL, so 0.1 mL delivers 500 mcg; adding 1 mL yields 10 mg/mL. These are calculations about the container, not a dosing recommendation.

Sources

Ordered by evidence quality — the strongest first.

  1. Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia(opens in a new tab)
    Tier 1Web · researchgate.net
  2. Functional Connectomic Approach to Studying Selank and Semax Effects.(opens in a new tab)
    Tier 1PubMed · pubmed.ncbi.nlm.nih.gov · 2020
  3. [Optimization of the treatment of anxiety disorders with selank].(opens in a new tab)
    Tier 1PubMed · pubmed.ncbi.nlm.nih.gov · 2015
  4. Selank Administration Affects the Expression of Some Genes ... - PMC(opens in a new tab)
    Tier 2Web · pmc.ncbi.nlm.nih.gov
  5. Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission(opens in a new tab)
    Tier 2Web · pmc.ncbi.nlm.nih.gov
  6. Selank: Research Evidence & Safety Profile | PeptideInsight(opens in a new tab)
    Tier 2Web · peptideinsight.com · 2026
  7. Selank, a Peptide Analog of Tuftsin, Attenuates Aversive Signs of Morphine Withdrawal in Rats.(opens in a new tab)
    Tier 2PubMed · pubmed.ncbi.nlm.nih.gov · 2022
  8. The Influence of Selank on the Level of Cytokines Under the Conditions of "Social" Stress.(opens in a new tab)
    Tier 2PubMed · pubmed.ncbi.nlm.nih.gov · 2021
  9. Effect of Selank on Morphological Parameters of Rat Liver in Chronic Foot-Shock Stress.(opens in a new tab)
    Tier 2PubMed · pubmed.ncbi.nlm.nih.gov · 2019
  10. Peptide-based Anxiolytics: The Molecular Aspects of Heptapeptide Selank Biological Activity.(opens in a new tab)
    Tier 2PubMed · pubmed.ncbi.nlm.nih.gov · 2018
  11. GABA, Selank, and Olanzapine Affect the Expression of Genes Involved in GABAergic Neurotransmission in IMR-32 Cells.(opens in a new tab)
    Tier 2PubMed · pubmed.ncbi.nlm.nih.gov · 2017
  12. Peptide Selank Enhances the Effect of Diazepam in Reducing Anxiety in Unpredictable Chronic Mild Stress Conditions in Rats.(opens in a new tab)
    Tier 2PubMed · pubmed.ncbi.nlm.nih.gov · 2017
  13. Tuftsin - Properties and Analogs.(opens in a new tab)
    Tier 2PubMed · pubmed.ncbi.nlm.nih.gov · 2017
  14. Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission.(opens in a new tab)
    Tier 2PubMed · pubmed.ncbi.nlm.nih.gov · 2016
  15. The temporary dynamics of inflammation-related genes expression under tuftsin analog Selank action.(opens in a new tab)
    Tier 2PubMed · pubmed.ncbi.nlm.nih.gov · 2014
  16. Selank (TP-7) - Clinical Monograph | Anxiolytic Nootropic Peptide Guide | PeptidePrescriber(opens in a new tab)
    Tier 3Web · peptideprescriber.com
  17. Selank Deep Dive: Anxiety, Cognition, Immune System - Mechanisms, Risks, Forms, & Dosing(opens in a new tab)
    Tier 3Web · youtube.com
  18. Selank Dosing Guide: Intranasal Research Protocols(opens in a new tab)
    Tier 3Web · parahealth.de
  19. Selank Peptide | Benefits, Safety & Buying Advice [2026](opens in a new tab)
    Tier 3Web · innerbody.com
  20. Selank Peptide | Calm & Cognitive Support(opens in a new tab)
    Tier 3Web · paragonsportsmedicine.com
  21. Selank Peptide: Anxiolytic Nootropic From Tuftsin(opens in a new tab)
    Tier 3Web · peptidepedia.org
  22. Superpower(opens in a new tab)
    Tier 3Web · superpower.com
  23. Selank: A Literature Review of the Russian Tuftsin Analog | Peerless Peptides(opens in a new tab)
    Tier 3Web · peerlesspeptides.com · 2026
  24. Selank: heptapeptide anxiolytic research from Russian neuropharmacology | Compound Review(opens in a new tab)
    Tier 3Web · compoundreview.org · 2026
  25. Selank Peptide: Clinical Evidence, Mechanisms, and Therapeutic Applications in 2026 | Peptide Publicus(opens in a new tab)
    Tier 3Web · peptidepublicus.com · 2026
  26. Selank: 25 Studies Reviewed (2026) | PepCodex(opens in a new tab)
    Tier 3Web · pepcodex.com · 2026
  27. Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions.(opens in a new tab)
    Tier 3PubMed · pubmed.ncbi.nlm.nih.gov · 2026
  28. Selank Peptide Benefits: Anxiety, Focus & Dosing(opens in a new tab)
    Tier 4Web · empiremedicaltraining.com
  29. Atrial fibrillation-associated electrical remodelling in human induced pluripotent stem cell-derived atrial cardiomyocytes: a novel pathway for antiarrhythmic therapy development.(opens in a new tab)
    Tier 4PubMed · pubmed.ncbi.nlm.nih.gov · 2023
  30. Long-term Survival of Adhesively Luted Post-endodontic Restorations.(opens in a new tab)
    Tier 4PubMed · pubmed.ncbi.nlm.nih.gov · 2022
  31. Isoselenocarbonyl complexes.(opens in a new tab)
    Tier 4PubMed · pubmed.ncbi.nlm.nih.gov · 2019