Selank

Selank is a synthetic analog of tuftsin, an endogenous immunomodulatory tetrapeptide, extended with a short proline-rich tail (Thr-Lys-Pro-Arg-Pro-Gly-Pro) that dramatically improves its metabolic stability without introducing the sedative liabilities typical of classical anxiolytics. In research settings, Selank is studied for anxiolytic-like effects in rodent behavioral assays, with proposed mechanisms centered on modulation of GABAergic and serotonergic signaling alongside changes in expression of brain-derived neurotrophic factor (BDNF) in the hippocampus and prefrontal cortex. What distinguishes it as a research subject is this dissociation from benzodiazepine pharmacology: models report anxiolytic-like behavior without the motor impairment, tolerance, or physical dependence signatures associated with GABA-A positive allosteric modulators, alongside measurable downstream effects on inflammatory gene expression, chemokine signaling, and monoamine turnover that suggest a broader immunomodulatory-neuroactive mechanism worth further characterization. Peptides.SO currently aggregates 145 supplier listings for Selank from 93 distinct vendors, 145 of them in stock as of September 2026; across the 54 listings whose quantities normalize to a per-milligram basis the median price is $5.00/mg, with the middle half of the market between $4.00 and $6.48/mg.

Mechanism of Action:

Selank's pharmacological profile is atypical because it arises from tuftsin, a tetrapeptide (Thr-Lys-Pro-Arg) produced by enzymatic cleavage of the Fc region of IgG. Tuftsin itself acts primarily as an immunostimulant via phagocyte receptors; Selank's Pro-Gly-Pro extension shifts the pharmacological activity profile toward neuromodulation while dramatically slowing peptidase-mediated degradation. Mechanistic studies in rodents point to several interlocking pathways. First, Selank modulates GABAergic transmission indirectly, increasing receptor sensitivity or synaptic GABA availability without direct GABA-A receptor binding — this explains the anxiolytic-like behavioral profile in the absence of GABA-A positive allosteric modulator side effects. Second, it alters serotonin turnover in key limbic structures, with reported increases in serotonin and its metabolite 5-HIAA in the frontal cortex and striatum. Third, it has been shown to increase BDNF mRNA expression in hippocampus and prefrontal cortex, connecting it to the neurotrophin regulation research space shared with Semax. Fourth, consistent with its tuftsin heritage, Selank modulates expression of interleukins and chemokines in neural tissue, providing a mechanistic link between neuroinflammation and anxiety-like behavior that is a subject of active investigation. Enkephalin system involvement has also been proposed via inhibition of enkephalin-degrading enzymes (enkephalinase), which would increase endogenous opioid peptide availability at relevant synapses.

Key Research Studies:

Kolik LG et al. demonstrated that Selank protected against ethanol-induced memory impairment in rats and modulated BDNF content in the hippocampus and prefrontal cortex, establishing a neurotrophin-mediated mechanism for its observed cognitive-protective effects in models of alcohol-related neuronal stress. PubMed PMID: 31625062.

Konstantinopolsky MA et al. showed that Selank significantly attenuated aversive signs of morphine withdrawal in rats — including wet-dog shakes, paw tremors, and grooming behaviors — a finding that implicates the enkephalin system and opioid-anxiety interactions as active research directions for this compound class. PubMed PMID: 36322304.

Semenova TP et al. documented Selank's effects on monoamine neurotransmitter levels in the rat brain during stress, finding region-specific changes in dopamine, serotonin, and norepinephrine that correlated with behavioral anxiolytic-like outcomes, providing a neurochemical map for the peptide's stress-buffering effects. PubMed PMID: 20063074.

Uchakina ON et al. investigated Selank's immunomodulatory effects in human subjects, documenting changes in interleukin-6, IL-2, and interferon-gamma gene expression profiles in peripheral lymphocytes, confirming that immune modulation deriving from the tuftsin backbone persists in the extended analog and is measurable in human tissue. PubMed PMID: 18698815.

Research Concentrations Used in Studies:

Rodent anxiolytic-like behavioral studies have used intranasal or subcutaneous doses of 100–300 mcg/kg body weight. Memory and neuroprotection studies have used similar dose ranges (0.1–0.5 mg/kg). Intranasal solutions are typically prepared at 0.1–0.15% (1–1.5 mg/mL) in sterile saline or phosphate-buffered saline at pH 5.5–7.0, matching the nasal mucosal environment. Subcutaneous preparations are used at 0.5–1 mg/mL. Stability after reconstitution is approximately 7–10 days at 4°C; lyophilized powder is stable for extended periods at −20°C.

Potential Research Applications:

Anxiolytic-like behavior in elevated plus maze, open field, and light-dark box models without sedation or motor impairment GABAergic and serotonergic system modulation studies using intracerebral microdialysis BDNF expression changes in hippocampus and prefrontal cortex with behavioral correlation Ethanol-induced memory impairment and neuroprotection models Immune and inflammatory gene expression regulation (interleukins, chemokines) in neuro-immune research Morphine withdrawal and opioid-anxiety interaction behavioral pharmacology Enkephalinase inhibition and endogenous opioid peptide dynamics Stress-response attenuation in chronic unpredictable stress models

Safety Profile from Published Research:

Selank has an established safety record in Russian preclinical studies and limited human studies. Rodent studies consistently report absence of motor impairment, sedation, and muscle relaxation at standard research doses — phenotypic signatures that distinguish Selank from benzodiazepines. No tolerance development was observed over standard multi-day protocols in available animal data. Withdrawal phenomena after cessation of chronic Selank dosing have not been reported in published preclinical literature, a further distinguishing feature versus classical GABAergic compounds. Acute toxicity studies in rodents showed tolerability at doses far exceeding typical research doses. No endocrine, hepatic, or renal toxicity has been documented in published preclinical reports. Human immunomodulatory studies reported generally mild and transient effects. As with all research peptides, the absence of formal IND-track safety data means this material is supplied strictly for laboratory research use only (RUO) and is not for human or veterinary use.

Marketplace Snapshot (September 2026, Peptides.SO listings data): Tracked listings: 145 from 93 distinct suppliers (145 in stock) Listings with a verifiable per-mg price: 54 Median price per mg: $5.00 (interquartile range $4.00 to $6.48) Lowest verified per-mg price: $1.83/mg Genetic Peptide: $55.00 for 30.1 mg ($1.83/mg) Sunrise Bioresearch: $98.99 for 50 mg ($1.98/mg) Pure Peptides UK: $21.00 for 10 mg ($2.10/mg) Listings that price by kit, bundle, or unit rather than by weight cannot be normalized to a per-mg basis and are excluded from the figures above. Prices change frequently; the live comparison table on this page reflects the most recent crawl.

Frequently Asked Questions:

Q: How many suppliers list Selank, and what is the going per-mg rate? A: Peptides.SO tracks 145 Selank listings across 93 distinct suppliers, all in stock at last crawl. Of those, 54 publish quantities that normalize to a per-milligram price; the median is $5.00/mg and the interquartile range runs $4.00 to $6.48/mg.

Q: What is the cheapest verified Selank listing on the platform? A: Genetic Peptide at $55.00 for approximately 30 mg, or $1.83/mg. Sunrise Bioresearch follows at $98.99 for 50 mg ($1.98/mg), and Pure Peptides UK offers a smaller 10 mg unit at $21.00 ($2.10/mg) for researchers who prefer not to commit to a large lot.

Q: Why is Selank studied as an alternative to benzodiazepine-class compounds? A: In rodent assays Selank produces anxiolytic-like behavioral profiles without the motor impairment, tolerance development, or withdrawal signatures characteristic of GABA-A positive allosteric modulators. That dissociation is the central reason it remains a subject of comparative behavioral pharmacology research.

Q: Does Selank act on GABA receptors directly? A: Published work does not support direct GABA-A receptor binding as the primary mechanism. Research instead points to indirect modulation of GABAergic and serotonergic tone alongside changes in BDNF expression in the hippocampus and prefrontal cortex, and to effects on inflammatory and chemokine gene expression consistent with its tuftsin lineage.

Q: How does Selank's tuftsin origin shape its research profile? A: Tuftsin is an endogenous immunomodulatory peptide that stimulates phagocytes and modulates cytokine production. Selank retains this immunomodulatory character — human studies have documented changes in interleukin and interferon gene expression — while the extended sequence shifts the primary research focus toward CNS and anxiolytic-like endpoints. This makes Selank uniquely interesting for research on neuro-immune interactions underlying stress and anxiety behaviors.

Q: What should be checked on a Selank certificate of analysis? A: Confirm HPLC purity, a mass-spectrometry identity match against the expected molecular weight for the heptapeptide, and that the lot number on the COA matches the vial shipped. Peptide content (net peptide versus gross powder weight) is a further useful figure, since it materially changes the effective per-mg cost.

Q: Is Selank approved for human use? A: No. It is supplied here strictly as a research chemical for laboratory investigation. It holds no FDA approval, and is not intended for human or veterinary use, diagnosis, or treatment of any condition.

Related Research on Peptides.SO: peptides.so/learn/selank-tuftsin-analog-anxiolytic-research peptides.so/peptide/semax peptides.so/learn/neuroprotective-peptides-compared-semax-selank-dihexa-p21 peptides.so/tools/calculator peptides.so/learn/coa-interpretation-guide

Cited Research: Kolik LG, Nadorova AV, Antipova TA, et al. Selank, Peptide Analogue of Tuftsin, Protects Against Ethanol-Induced Memory Impairment by Regulating of BDNF Content in the Hippocampus and Prefrontal Cortex in Rats. Bulletin of Experimental Biology and Medicine. 2019. PubMed PMID: 31625062. Konstantinopolsky MA, Chernyakova IV, Kolik LG. Selank, a Peptide Analog of Tuftsin, Attenuates Aversive Signs of Morphine Withdrawal in Rats. Bulletin of Experimental Biology and Medicine. 2022. PubMed PMID: 36322304. Semenova TP, Kozlovskaya MM, Zuikov AV, et al. Effects of Selank on the Content of Biogenic Amines in the Brain. Bulletin of Experimental Biology and Medicine. 2009. PubMed PMID: 20063074. Uchakina ON, Uchakin PN, Miasoedov NF, et al. Immunomodulatory Effects of Selank in Patients with Anxiety-Asthenic Disorders. Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova. 2008. PubMed PMID: 18698815.

For laboratory research only. Not for human or veterinary use, diagnosis, treatment, cure, or prevention of any disease. THIS PRODUCT IS NOT FOR HUMAN CONSUMPTION.