# Selank: Research Overview — NewGen Peptides > A literature summary of Selank (tuftsin analog heptapeptide), a Cognitive & Nootropic research peptide studied for anxiety reduction via GABAergic modulation — regulatory context, mechanisms and cited evidence. A tuftsin-derived heptapeptide that modulates GABA receptor binding and enkephalin-degrading enzymes — studied for anxiety reduction without the sedation profile of benzodiazepines. ## The short version **Selank** is a synthetic seven-amino-acid peptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) derived from tuftsin, an endogenous tetrapeptide fragment of immunoglobulin G that the body uses to modulate immune and stress responses. The C-terminal Pro-Gly-Pro tail was added, as with Semax, to slow enzymatic breakdown. In rodent and limited human research, Selank reduces anxiety — not by sedating the system like benzodiazepines, but by acting as a **positive allosteric modulator of GABA receptor binding** [8] and by shifting the expression of GABA-pathway genes in frontal cortex [10]. The honest framing: most efficacy data are from rodents or small Russian clinical studies. There are no FDA- or EMA-approved indications, no large Western randomized controlled trials, and the human evidence is limited to short trial courses in Russian patients with anxiety disorders. Selank is not a regulated pharmaceutical in the United States; it is a research chemical. This page reports what the published studies show; it is not medical advice and carries no human dosing. ## What it is Selank (also called TP-7) is a *synthetic heptapeptide anxiolytic* derived by extending the endogenous tetrapeptide tuftsin (Thr-Lys-Pro-Arg) with the metabolic-stabilizing Pro-Gly-Pro tripeptide at its C-terminus. Tuftsin itself is a fragment of the Fc region of IgG heavy chains and naturally engages immune and phagocytic regulation — Selank inherits some of that immune-signaling character while gaining the CNS anxiolytic and nootropic properties studied in its own right. Outside Russia, Selank has no approved pharmaceutical form. It is supplied as a research chemical, typically as a lyophilized powder reconstituted for intranasal or subcutaneous use in laboratory settings. ## How it works The primary anxiolytic mechanism is **positive allosteric modulation of GABA receptor binding**. In rat brain membrane preparations, Selank modulates [³H]GABA binding in a subtype-selective, concentration-dependent manner that differs from benzodiazepines — it can even block the modulatory activity of diazepam and olanzapine at distinct binding sites [8]. At the gene-expression level, Selank administration changed the expression of 45 GABA-pathway genes in rat frontal cortex one hour after dosing and 22 genes at three hours, with the pattern positively correlated to that induced by GABA itself [10]. A second convergent mechanism is **enkephalin-degrading enzyme inhibition**. In human serum in vitro, Selank inhibited neprilysin-type enkephalinases at an IC50 of approximately 20 micromolar [7] — about half the potency of Semax — which is proposed to extend endogenous enkephalin signaling and contribute to the anxiolytic and mood-stabilizing effects. At the neurotrophin level, intranasal Selank increased BDNF expression in the rat hippocampus [11], suggesting a neuroplasticity-linked mechanism that may underlie the reported cognitive dimension of its effects. In human patients with anxiety-asthenic disorders, Selank shifted Th1/Th2 cytokine balance and modulated peripheral-blood IL-6 expression [12] — characterizing it as an immunomodulator as well as an anxiolytic, which reflects its tuftsin lineage. The combination of GABAergic, opioid-peptide, neurotrophic and immune-signaling activity across multiple systems is mechanistically plausible but also means interactions with medications targeting any of those systems are unstudied. ## What the research shows *GABAergic mechanism and allosteric modulation.* A 2018 review established that Selank's anxiolytic activity centers on positive allosteric modulation of GABA receptor binding with subtype-selective, concentration-dependent effects different from benzodiazepines [8]. This remains the best-characterized molecular finding. *Anxiety reduction in UCMS.* In rats subjected to unpredictable chronic mild stress, combining diazepam with Selank produced the largest anxiety reduction of any treatment arm tested — a co-administration effect consistent with their shared GABAergic action and supporting the allosteric-modulation model [9]. *GABAergic gene expression.* In rat frontal cortex, Selank produced a significant, time-dependent change in 45 GABA-pathway genes at one hour and 22 at three hours, with expression shifts that positively correlated to those induced by GABA itself [10]. *BDNF upregulation in hippocampus.* Intranasal Selank increased BDNF expression in the rat hippocampus in vivo, linking the peptide to neuroplasticity pathways and providing a candidate mechanism for the reported nootropic dimension beyond anxiety relief [11]. *Human immunomodulation in anxiety patients.* In a clinical study with patients diagnosed with anxiety-asthenic disorders, Selank shifted Th1/Th2 cytokine balance and modulated IL-6 expression — the most direct human molecular data in the corpus, confirming the immunomodulatory profile inherited from tuftsin [12]. ## Reported effects, cautions & safety **Community-reported effects (anecdotal, not clinical evidence).** The nootropic community's most consistent report is a *calm without sedation* — the volume on background anxiety turned down while energy and clarity hold steady, explicitly contrasted with the heavy, foggy quality of benzodiazepines. Situational use before high-stakes events (exams, presentations, difficult conversations) is very commonly described, with users reporting fewer nerves and a heart rate that stayed low. A "calm but sharp" focus quality — attributed to quieted anxious mental chatter rather than a direct stimulant push — is frequently mentioned. A substantial minority report little or no perceptible effect; this is an honest and common outcome. Adverse effects from the same communities include mild nasal irritation from the intranasal solution, occasional headache, and, in a minority, slightly too much calm or mental softness that some users tie to heavier use. **Cited safety cautions.** Several cautions emerge from the literature: - *Unregulated research-chemical supply.* Outside Russia, Selank is not a pharmaceutical product; identity, purity and actual peptide content vary by supplier and are not independently guaranteed. - *Long-term safety not established.* Human data are confined to short Russian trial courses in diagnosed patients; there is no long-term independent safety follow-up. - *Multi-system interaction unknowns.* Selank touches GABAergic, opioid-peptide, monoaminergic and immune-signaling systems [8][9][10][12]. Combination with GABAergic sedatives, opioids, or serotonergic/dopaminergic drugs carries unstudied additive-effect risk. - *Immune-signaling activity.* As a tuftsin analog, Selank shifts Th1/Th2 balance and cytokine levels [12]. Long-term consequences for people with autoimmune conditions, active infection, or immune-modulating medications are not characterized. - *Not a substitute for clinical anxiety care.* Persistent or impairing anxiety is a medical condition with evidence-based treatments and clinical oversight. An unapproved research peptide is not a substitute for professional evaluation. ## Where it fits Among the three peptides on this desk, Selank approaches the cognitive-nootropic question through the anxiety axis — its mechanism is the most directly human-relevant of the three (with a clinical immunomodulation finding in actual patients [12]) and it has the clearest separation from a sedative risk profile. Against [Semax](/semax), which operates primarily through BDNF/NGF and neuroprotection, Selank is the anxiolytic complement — quiet focus through anxiety relief rather than growth-factor upregulation. Against [DSIP](/dsip), it offers a more characterized mechanism. See the [comparison page](/compare) for a structured view across all three. ![Selank — abstract GABA receptor modulation on a deep navy ground](/images/selank.webp) --- A peer-reviewed literature digest on research peptides — not a clinic, not a vendor, not a dosing guide.