Compound reference
Selank
Also known as TP-7
Selank is a synthetic tuftsin-derived heptapeptide, approved in Russia as an anxiolytic that calms anxiety without benzodiazepine-style sedation or dependence. Its evidence is real but largely a single Russian research tradition, with limited independent Western replication and no FDA approval.
- CAS
- 129954-34-3
- Formula
- C₃₃H₅₇N₁₁O₉
- Molar mass
- ≈751.9 g/mol
- Sequence
- Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP) — the tuftsin fragment plus a Pro-Gly-Pro stabilizer
Regional/research peptide; not FDA-approved as a drug in the United States.
Mode of action
Selank is a synthetic heptapeptide, Thr-Lys-Pro-Arg-Pro-Gly-Pro. Its front half is tuftsin (Thr-Lys-Pro-Arg), a naturally occurring immunomodulatory tetrapeptide, and — as with Semax — its back half is a Pro-Gly-Pro stabilizer that resists enzymatic degradation. It comes from the same Russian research program (the Institute of Molecular Genetics), and is also given intranasally.
Its signature effect is anxiolytic, and the proposed mechanism is what makes it interesting: rather than acting as a benzodiazepine, Selank appears to be a positive allosteric modulator of GABAergic neurotransmission. Binding studies show it alters GABA receptor characteristics, and it changes the expression of GABAergic genes in the brain — producing a benzodiazepine-like calming spectrum without the sedation, muscle relaxation, tolerance, or dependence that limit benzodiazepines. It also engages serotonergic pathways, inhibits enkephalin-degrading enzymes (raising enkephalin levels), influences BDNF, and retains tuftsin's immunomodulatory activity. As with Semax, the mechanism is plausible and multi-layered but largely documented by one research lineage.
Main intended effect
Anxiolysis — reducing anxiety — together with anti-asthenic and mild nootropic effects, the selling point being relief without benzodiazepine-style drawbacks.
Areas of interest
The lead indication is generalized anxiety disorder, for which Selank is approved and used in Russia; related uses there include neurasthenia and stress-related and asthenic conditions, with additional interest in its immunomodulatory effects. Outside Russia it circulates as an anti-anxiety and nootropic research peptide, typically as a nasal spray.
Evidence for intended effects
Like Semax, Selank has real clinical use rather than purely speculative status: it is a registered anxiolytic in Russia, and Russian clinical work supports that role. A randomized study in anxiety-spectrum disorders found that adding Selank to the benzodiazepine phenazepam brought on the therapeutic effect earlier while significantly reducing benzodiazepine side effects — sedation, memory impairment, sleep disturbance — and improving quality of life. Other reports examine its onset kinetics in generalized anxiety disorder. The mechanistic literature (GABA modulation, gene expression, enkephalinase inhibition) is consistent with an anxiolytic that spares the benzodiazepine liabilities.
The same provenance caveat applies. The evidence base is predominantly early-phase Russian research from a single tradition, with limited large controlled trials and little independent Western replication. Regulators outside Russia have not approved it: the FDA briefly listed Selank acetate as a Category 2 bulk substance over safety-risk and impurity concerns, then removed it when the compounding nomination was withdrawn — neither step being an approval. And it appears in the same forensic surveys of seized "nootropic" peptides as Semax, sold online without having completed Western clinical trials.
| Strand | What exists | Tier |
|---|---|---|
| Generalized anxiety disorder | Russian controlled/clinical studies; approved in Russia | Regional clinical (limited replication) |
| Mechanism | GABA allosteric modulation, gene expression, enkephalinase | Strong preclinical (single tradition) |
| Western regulatory | No approval; transient FDA 503A Category 2 then withdrawn | Not approved |
Studied amounts (literature dosing context)
Selank is administered intranasally (the Russian product is a nasal-spray formulation), and clinical studies have used it both on its own and as an add-on to benzodiazepines such as phenazepam. Specific regimens come from regional trials and product labeling rather than international dose-finding studies; there is no FDA-approved dose, and this page does not provide dosing guidance.
Safety and regulatory status
Selank's claimed advantage is precisely safety-related: an anxiolytic effect without the sedation, cognitive blunting, tolerance, and dependence of benzodiazepines, a profile supported by its Russian clinical use. As with Semax, that record sits mostly within one regional literature and has not been confirmed in large independent trials. Selank is not FDA- or EMA-approved; its brief appearance on the FDA 503A Category 2 list (later withdrawn) reflects unresolved questions about immunogenicity and impurities in compounded peptide, not an endorsement. Material sold online is an unregulated gray-market research compound of unverified identity and purity.
Sources
A new generation of drugs: synthetic peptides based on natural regulatory peptides
Narrative review in Neuroscience and Medicine examining synthetic peptide drugs derived from natural regulatory peptides, with particular focus on Semax (an ACTH4-10 analogue) and Selank (derived from tuftsin). Selank is described as a potent anxiolytic used for generalized anxiety disorder and neurasthenia, acting through modulation of enkephalin-degrading enzymes and monoamine systems without sedative or muscle-relaxant effects; Semax is highlighted for neuroprotective actions against ischemic injury via nitric oxide suppression and BDNF upregulation. Both peptides demonstrate altered gene expression in hippocampus and spleen affecting neurotrophin signaling and neuroinflammation. The authors note that synthetic modifications confer improved metabolic stability over natural precursors, addressing rapid proteolytic degradation in biological media.
Peptide-based anxiolytics: the molecular aspects of heptapeptide Selank biological activity
Narrative review in Research Results in Pharmacology examining the molecular mechanisms underlying the anxiolytic activity of the synthetic heptapeptide Selank, a stable analogue of the natural immunomodulator tuftsin. The review consolidates preclinical and clinical mechanistic findings across neurotransmitter systems including GABAergic, serotonergic, and enkephalinergic pathways, as well as effects on BDNF and neurotrophin signaling. Selank is characterized as producing anxiolytic effects without the sedative or muscle-relaxant liabilities associated with benzodiazepines. The evidence base is predominantly preclinical and early-phase Russian research, with limited large controlled clinical trials available at time of publication.
Peptide regulation of specific ligand-receptor interactions of GABA
Biochemical study (Neurochemical Journal, 2016) characterizing the modulatory effects of Selank and related regulatory peptides on specific ligand-receptor interactions at GABA receptors using binding assays. Selank was found to alter GABA receptor binding characteristics, consistent with an allosteric modulatory mechanism rather than direct agonism at the orthosteric site. These binding data are cited in the related 2016 mouse brain gene expression study (Kolomin et al.) as evidence that Selank acts via allosteric modulation of GABAergic neurotransmission. Receptor binding experiments were conducted with isolated receptor preparations; how these interactions translate to receptor function and therapeutic effects in intact neural circuits or human subjects remains to be established.
Selank administration affects the expression of some genes involved in GABAergic neurotransmission in the mouse brain
Kolomin and colleagues (PMC4757669) administered a single intranasal dose of Selank at 300 µg/kg to male Wistar rats and analyzed real-time PCR expression of 84 neurotransmission-related genes in the frontal cortex at 1 and 3 hours. At 1 hour, 45 genes showed significant changes (p ≤ 0.05, ≥1.5-fold), with 76% displaying decreased expression; notable reductions included Gabre, Gabrq, and HcRt (15–50-fold decreases), while Drd3 increased 2–3-fold. By 3 hours, only 22 genes were altered and 95% were increased, with HcRt rebounding 128-fold and Gabre rising 16-fold. Selank's expression profile correlated strongly with that of GABA (r = 0.86 at 1 hour), and the authors proposed allosteric modulation of GABAergic signaling as the primary mechanism. These are rodent frontal cortex data; gene expression changes in human neural tissue have not been characterized.
Inhibitory effect of Selank on enkephalin-degrading enzymes in vitro
In vitro biochemical study (Bulletin of Experimental Biology and Medicine, 2001) characterizing the direct inhibitory effect of Selank on enkephalin-degrading enzymes. Selank, as a heptapeptide tuftsin analogue, was incubated with enzyme preparations and shown to reduce the catalytic degradation of endogenous enkephalins, with the inhibitory potency reported across enzyme substrates relevant to neuropeptide catabolism. This mechanism is proposed to explain how a peripherally administered peptide can elevate effective enkephalin concentrations at central and peripheral receptor sites, contributing to Selank's anxiolytic and anti-stress profile. The findings are from cell-free enzyme assays; whether equivalent enzyme inhibition occurs in vivo in humans at pharmacological doses has not been established.
Optimization of the treatment of anxiety disorders with the use of Selank in combination with benzodiazepine tranquilizers
Randomized controlled trial published in Zh Nevrol Psikhiatr, enrolling 70 patients with anxiety-phobic, hypochondriac, and somatoform disorders (ICD-10 F40–F45); 30 received phenazepam monotherapy and 40 received Selank combined with phenazepam. The combination group achieved the positive effect of phenazepam earlier per Hamilton Depression Rating Scale scores, and demonstrated significantly reduced adverse effects including sedation, memory impairment, sleep disturbance, sexual dysfunction, and emotional blunting. Quality of life assessed by SF-36 improved significantly in the combination arm. The authors conclude that Selank broadens therapeutic options for anxiety-spectrum disorders by augmenting benzodiazepine efficacy while mitigating tolerability drawbacks.
Rapid and slow response during treatment of generalized anxiety disorder with peptide anxiolytic Selank
Clinical report published in European Psychiatry examining differential response kinetics among patients with generalized anxiety disorder treated with Selank. The study characterizes rapid versus slow responders to the heptapeptide anxiolytic and explores clinical or biological factors distinguishing the two response patterns. The findings contribute to understanding the onset-of-action profile of Selank relative to established anxiolytics and may inform patient selection or treatment sequencing in GAD. Methodological details including population size and specific outcome measures are not available from the conference abstract.
Selank Acetate Bulk Drug Substance for Compounding (FDA)
FDA bulk-substances compounding record tracking the regulatory history of Selank acetate (TP-7) under the 503A framework. In September 2023, FDA placed Selank acetate on the interim Category 2 list of substances that may present significant safety risks, citing concerns about immunogenicity risk, peptide-related impurities, and insufficient human safety and efficacy data to support compounded use. In September 2024, Selank acetate was removed from the interim Category 2 list following withdrawal of its 503A nomination by the nominator. Removal from the interim list is not an approval and does not authorize compounding; the substance lacks an approved new drug application and cannot be lawfully compounded under 503A without a nomination and favorable evaluation. Selank has no FDA-approved therapeutic indication in any dosage form.
The occurrence of putative cognitive enhancing research peptides in seized pharmaceutical preparations
Forensic and analytical study (Vanhee, Francotte, Janvier, and Deconinck, Drug Testing and Analysis 2020) reporting detection of the cognitive-enhancing research peptides Semax and Selank in pharmaceutical preparations seized by controlling agencies. The authors note that, despite being marketed and used as nootropics, these peptides had not completed any clinical trials in the Western regulatory sense, and an accompanying online survey found them freely available as lyophilized powder for injection or in nasal sprays. They developed a liquid chromatography–tandem mass spectrometry method to identify such peptides and framed the seizures as an incentive for regulators to prepare for further encounters. Illustrates the gray-market reality and unverified provenance of Semax and Selank products sold outside their countries of regional approval.
Evaluation of Research Grade Peptides Marketed Directly to Consumers Reveals Extensive Variability in Purity and Measured Abundance
Analysis (Mendias and Awan, preprint, 2026) of 6,441 gray-market peptide samples across fourteen compounds — including ipamorelin, BPC-157, CJC-1295, GHK-Cu, PT-141, retatrutide, semaglutide, sermorelin, TB-500, tesamorelin, and tirzepatide. Applying two quality-acceptance frameworks, between 41.6% and 71.1% of samples failed to meet basic quality criteria, and about 15% showed measurable endotoxin contamination. The study quantifies how often directly-marketed "research grade" peptides miss purity and content benchmarks — a central safety concern for any non-pharmaceutical source.