Built on an immunoglobulin fragment rather than a pituitary hormone, which is why its research sits in anxiolytic and immune signalling rather than cognition.
- Sequence
- Thr-Lys-Pro-Arg-Pro-Gly-Pro (tuftsin + Pro-Gly-Pro)
- Molecular formula
- C33H57N11O9
- Molecular weight
- 751.9 g/mol
- CAS number
- 129954-34-3
- Appearance
- white lyophilised powder
- Strengths available
- 5mg, 10mg per vial
- Purity
- ≥99% by HPLC, identity confirmed by mass spectrometry
- Released against
- the Certificate of Analysis for its own batch
About Selank
Tuftsin is a tetrapeptide, Thr-Lys-Pro-Arg, released from the Fc region of immunoglobulin G heavy chain, with a well-documented role in stimulating macrophage and neutrophil function. Selank is tuftsin extended by Pro-Gly-Pro, the same protease-resistant motif used to stabilise Semax, giving Thr-Lys-Pro-Arg-Pro-Gly-Pro.
The two compounds came out of the same Russian research programme and share a design philosophy, but not a parent molecule and not a reported mechanism. Semax derives from a pituitary hormone fragment; Selank derives from an immune peptide, which is why it retains a documented immunomodulatory strand that Semax does not have.
What the research covers
The reported profile is anxiolytic, and the mechanistically interesting part is what is absent: Selank does not bind the benzodiazepine site on the GABA-A receptor. Published work instead describes modulation of GABA-A subunit expression, effects on serotonin turnover, and influence on the enkephalin system through inhibition of enkephalin-degrading enzymes. The usual liabilities of benzodiazepine-site agonists, such as sedation, tolerance and dependence, follow from that binding, so a compound reaching an anxiolytic readout without it is pharmacologically a different thing. Whether the indirect routes fully account for the effects remains open.
The immune strand covers cytokine balance and interleukin expression inherited from its tuftsin parentage, and some authors treat the behavioural and immune findings as connected. Much of the primary literature was published in Russian-language journals, and methodological detail is not always recoverable from the translations in circulation, which is worth knowing when an English-language search looks thinner than the actual evidence base. Published work is indexed on PubMed.
Handling Selank
Supplied lyophilised. As with Semax, the Pro-Gly-Pro tail protects against enzymatic degradation but not against adsorption, and at the low concentrations typical of behavioural and cell work the latter is the larger practical loss.
Low-binding plasticware, gentle reconstitution, cold sealed storage at -20°C and freshly prepared working solutions. Solvent options are under reconstitution supplies.
Other formats
Selank is also supplied as a metered 20ml Selank nasal spray, where no reconstitution step is needed.
Common questions about Selank
What is Selank derived from?
Tuftsin, a four-residue immune peptide released from immunoglobulin G, extended with the stabilising Pro-Gly-Pro tail.
Does Selank act on the benzodiazepine site?
No. Its reported anxiolytic effects run through indirect routes, including GABA-A subunit expression, serotonin turnover and the enkephalin system.
Why does that difference matter?
Sedation, tolerance and dependence are linked to benzodiazepine-site binding, so a compound acting without it is pharmacologically distinct.
How does Selank differ from Semax?
They share the Pro-Gly-Pro tail but have different parent molecules: Selank an immune peptide, Semax a pituitary hormone fragment.
How should Selank be stored?
Sealed vials at -20°C. Solutions are prepared fresh in low-binding plasticware.
