Selank Peptide Pen (Tuftsin Analogue) | 20mg

Selank is a synthetic heptapeptide developed at the Institute of Molecular Genetics in Moscow, supplied here pre-mixed at 20 mg in a 3 ml stabilised cartridge at a stated 6.67 mg/ml. No reconstitution step, no separate diluent.

What selank is

The sequence is Thr-Lys-Pro-Arg-Pro-Gly-Pro. Reading it in two halves explains the design. The first four residues, Thr-Lys-Pro-Arg, are tuftsin — a naturally occurring tetrapeptide released from the Fc region of immunoglobulin G, long studied for its effects on phagocyte activity. The final three, Pro-Gly-Pro, are a stabilising extension bolted on to slow enzymatic degradation of the parent tetrapeptide, which is otherwise cleared very quickly.

That Pro-Gly-Pro tail is not incidental, and it is the reason Selank and Semax are usually discussed together. Both were developed by the same group using the same trick: take a short native peptide fragment with known activity, append PGP, and obtain a molecule that survives long enough to be measurable. Semax applies it to ACTH(4–10); Selank applies it to tuftsin. The two are structural cousins by method rather than by sequence.

At 751.9 g/mol Selank is a small, highly soluble peptide with no cysteines and therefore no disulfide bridge to reduce — which makes it comparatively forgiving in solution next to larger constructs.

Selank pen: the same thing under a shorter name

Most people searching for this product type “selank pen” rather than the full compound name, and the two mean the same thing. A selank pen is a pre-filled Selank cartridge in a dial-dosing pen, as opposed to lyophilised powder in a vial.

This pen holds 20 mg in a sealed 3 ml cartridge, at 6.67 mg/ml. The dial is graduated at 4 clicks = 250  mcg. Those are device figures — what the mechanism displaces, not what should be dispensed.

Applications in research

• GABAergic gene expression. The best-documented laboratory finding is Selank's effect on the expression of genes involved in GABAergic neurotransmission, characterised in rat brain tissue and in comparison with GABA itself and with olanzapine.
• Enkephalin degradation. Work on Selank's reported inhibition of enkephalin-degrading enzymes, placing it in studies of endogenous opioid peptide turnover rather than receptor binding.
• Immunomodulatory activity. Assays inherited from the tuftsin literature — cytokine expression and phagocyte function — where the question is how much of the parent tetrapeptide's activity the extended peptide retains.
• Peptide stability methodology. Comparative degradation studies using tuftsin and Selank as a matched pair, where the PGP extension is the single structural variable.

The clinical literature on Selank is almost entirely Russian-language, from a small number of centres, and consists of small studies. It is real literature and it is thin; that is a fair summary of the evidence base, and it describes the molecule rather than this material.

Is Selank legal in the UK?

Selank is not a licensed medicine in the United Kingdom and holds no MHRA marketing authorisation. It is registered as a medicine in Russia; that registration has no standing here.

It is not a controlled drug under the Misuse of Drugs Act 1971. Buying and possessing it in the UK for laboratory research is lawful. Supplying it for human or veterinary consumption is not, and would engage the Human Medicines Regulations 2012. Every cartridge is labelled and supplied strictly for in-vitro research use.

What you are actually comparing between listings

• Total mass. This cartridge holds 20 mg. The standard presentation across UK suppliers is a 5 mg vial, so one unit here carries roughly four times the peptide of a typical listing. On a 5 mg basis the comparison on headline price is not a comparison at all.
• Format. Pre-mixed solution at a stated 6.67 mg/ml, against lyophilised powder that must be reconstituted — which means sourcing bacteriostatic water, calculating a concentration and accepting the variance that step introduces between preparations.
• Cost per milligram. At £110 for 20 mg this works out at £5.50 per mg. That is the figure that compares across listings.

Handling and storage

Store at 2–8 °C and protect from light. Keep the cartridge sealed until use, then upright, and observe aseptic technique. Do not freeze. Short proline-rich peptides are relatively robust, but the arginine and lysine residues make the molecule sensitive to oxidative conditions, so keep it out of light and away from prolonged warmth. Orders placed before 2pm are dispatched the same working day, cold-packed, in plain outer packaging.

References

Literature on the molecule. These describe Selank as a compound and none is a claim about this product.

1. Volkova A, Shadrina M, Kolomin T, et al. Selank Administration Affects the Expression of Some Genes Involved in GABAergic Neurotransmission. Front Pharmacol. 2016;7:31. PMID 26924987.
2. Filatova E, Kasian A, Kolomin T, et al. GABA, Selank, and Olanzapine Affect the Expression of Genes Involved in GABAergic Neurotransmission in IMR-32 Cells. Front Pharmacol. 2017;8:89. PMID 28293190.
3. Uchakina ON, Uchakin PN, Miasoedov NF, et al. Immunomodulatory effects of selank in patients with anxiety-asthenic disorders. Zh Nevrol Psikhiatr Im S S Korsakova. 2008;108(5):71–5. PMID 18577961.

Research use only

This material is supplied strictly for in-vitro research and analytical purposes. It is not for human or veterinary administration and not for any diagnostic or therapeutic application. It holds no MHRA marketing authorisation. Confirm the current regulatory position before drafting institutional documentation, and clear the material through your own ethics, COSHH and biosafety processes before ordering.