Selank Peptide: the tuftsin-derived heptapeptide
Selank peptide is a synthetic heptapeptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) built from the immune peptide tuftsin with a Pro-Gly-Pro tail added for stability. It was developed in Russia as an anxiolytic research compound. Published work includes small open-label clinical reports in anxiety disorders (Zozulia et al., 2008; Medvedev et al., 2015) and rodent studies on GABAergic gene expression, enkephalin-degrading enzymes and hippocampal BDNF. None of these establish efficacy to FDA standards. Researchers looking to buy selank for laboratory work can find ≥98% purity, HPLC-tested vials here — research use only.
Specifications
| Sequence | Thr-Lys-Pro-Arg-Pro-Gly-Pro (7 amino acids) |
|---|---|
| Origin | Tuftsin (Thr-Lys-Pro-Arg) with C-terminal Pro-Gly-Pro |
| CAS number | 129954-34-3 |
| Purity | ≥98% (HPLC) |
| Form | Lyophilised powder |
| Evidence basis | Small Russian clinical reports; mostly rodent mechanism studies |
What is selank?
Selank is a synthetic analog of tuftsin, a natural tetrapeptide (Thr-Lys-Pro-Arg) cleaved from the Fc region of immunoglobulin G and involved in immune signalling. Researchers at the Russian Academy of Sciences extended tuftsin with a Pro-Gly-Pro sequence — the same stabilising tail used in Semax — producing the seven-amino-acid peptide now studied as selank.
It is classified as an anxiolytic research peptide and is frequently compared with Semax, another Russian-developed peptide with a different parent molecule and research focus.
Proposed mechanisms: what the studies measured
No single receptor target has been established for selank. Published work instead points to several systems, each measured in a specific model:
- GABAergic signalling — in rats, selank changed the expression of genes involved in GABAergic neurotransmission in the frontal cortex (Volkova et al., 2016).
- Enkephalin metabolism — in vitro, selank inhibited enkephalin-degrading enzymes in human plasma (Zolotarev et al., 2004), and naloxone blocked some of its behavioural effects in mice, implicating the opioid system (Meshavkin et al., 2006; Kozlovskii et al., 2012).
- Neurotrophins — in rats given ethanol, selank was associated with preserved memory performance and altered BDNF content in the hippocampus and prefrontal cortex (Kolik et al., 2019).
What the clinical reports established
Zozulia et al. (2008) reported on selank in patients with generalised anxiety disorder and neurasthenia, and Medvedev et al. (2015) reported on its use in anxiety disorders. Both are Russian-language publications with small samples, and they are not the large, blinded, placebo-controlled trials used to approve medicines in the United States.
These reports establish that selank has been studied in humans in Russia; they do not establish efficacy, optimal exposure or long-term safety by FDA standards.
What has not been established
There is no large Western randomised controlled trial of selank, no characterised primary receptor, and limited independent replication outside the originating Russian research groups. Mechanistic findings come mainly from rodents and cannot be assumed to translate directly to people.
Selank vs Semax
Both are short synthetic peptides developed in Russia that share the Pro-Gly-Pro tail, but they come from different parent molecules. Selank derives from the immune peptide tuftsin and is studied mainly in anxiety-related models; Semax derives from an ACTH fragment and is studied mainly in cerebral ischemia, cognitive and stress models. See the Semax vs Selank comparison for a side-by-side view.
Handling in the lab
Store lyophilised selank sealed, cold and protected from light and moisture. After reconstitution with bacteriostatic water, refrigerate the solution and avoid repeated freeze–thaw cycles. Record lot numbers and match each vial to its certificate of analysis.
Frequently asked questions
What is selank peptide?
A synthetic seven-amino-acid peptide (Thr-Lys-Pro-Arg-Pro-Gly-Pro) derived from tuftsin, studied in anxiety-related research models.
How does selank work?
No single receptor has been established. Studies point to effects on GABAergic gene expression, enkephalin-degrading enzymes and BDNF, measured mostly in rodents and in vitro.
Is there clinical research on selank?
Small Russian clinical reports describe its use in generalised anxiety disorder and neurasthenia. They are not large, blinded, placebo-controlled trials.
Does selank act on the opioid system?
Indirectly, possibly. It inhibited enkephalin-degrading enzymes in human plasma in vitro, and naloxone blocked some of its effects in mice. It is not an opioid receptor agonist.
What is tuftsin?
A natural four-amino-acid peptide (Thr-Lys-Pro-Arg) released from immunoglobulin G that is involved in immune signalling. Selank is tuftsin plus a Pro-Gly-Pro tail.
Why does selank have a Pro-Gly-Pro tail?
The Pro-Gly-Pro extension was added to slow enzymatic breakdown. Semax uses the same tail.
What is the difference between selank and semax?
Selank is a tuftsin-derived heptapeptide studied in anxiety models; Semax is an ACTH-fragment heptapeptide studied in ischemia, cognitive and stress models.
Is selank an approved drug?
Not in the United States. It is registered in Russia but has no FDA approval and is sold here strictly for laboratory research.
What hasn't been established about selank?
Large Western controlled trials, a primary receptor target and independent replication outside the originating groups.
Where can I buy selank peptide for research?
PeptidesDirect sells selank in 10mg vials for laboratory research only. Orders placed before 1:00 PM Central on business days ship the same day. See our research peptides guide research peptides guide for how to compare suppliers and read test documents.
Product pages: Selank 10mg · Semax
How should selank be stored?
Keep lyophilised selank cold, dry and away from light; refrigerate reconstituted solutions and avoid repeated freeze–thaw cycles.
Is this product for human use?
No. PeptidesDirect sells this compound for laboratory research only. It is not a drug, food or cosmetic and is not for human or veterinary use. This page summarises published research and is not dosing or medical guidance.
Shop the compounds covered in these FAQs: Selank 10mg · Semax
References
- Zozulia AA, et al. Efficacy and possible mechanisms of action of a new peptide anxiolytic selank in the therapy of generalized anxiety disorders and neurasthenia. Zh Nevrol Psikhiatr Im S S Korsakova. 2008. PubMed 18454096
- Medvedev VE, et al. Optimization of the treatment of anxiety disorders with selank. Zh Nevrol Psikhiatr Im S S Korsakova. 2015. PubMed 26356395
- Volkova A, et al. Selank administration affects the expression of some genes involved in GABAergic neurotransmission. Front Pharmacol. 2016. PubMed 26924987
- Zolotarev IuA, et al. Leu-enkephalin homogeneously labeled with tritium in studying the Selank inhibiting effect on the enkephalin-degrading enzymes of human plasma. Bioorg Khim. 2004. PubMed 15344652
- Meshavkin VK, et al. Naloxone-blocked depriming effect of anxiolytic selank on apomorphine-induced behavioral manifestations of hyperfunction of dopamine system. Bull Exp Biol Med. 2006. PubMed 17415472
- Kozlovskii II, et al. The role of opioid system in peculiarities of anti-anxiety effect of peptide anxiolytic selank. Eksp Klin Farmakol. 2012. PubMed 22550852
- Kolik LG, 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. Bull Exp Biol Med. 2019. PubMed 31625062
Research compounds
Related guides
- Selank Peptide Research: Mechanisms
- Semax vs Selank
- Semax research guide
- Research peptides guide
- Reconstitution guide
- Storage guide
Research Use Only. Not for human or veterinary use. Not dosing or medical guidance.
