Selank + Semax

What is Selank + Semax?

This is a pre-blended research vial co-formulating two Russian-developed nootropic heptapeptides at 10mg each. Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) is a synthetic analogue of tuftsin, the endogenous immunomodulatory tetrapeptide released from immunoglobulin G, with CAS 129954-34-3 and molecular weight 751.9 g/mol. Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic analogue of the ACTH(4-10) fragment, with CAS 80714-61-0 and molecular weight 813.7 g/mol. Both were developed at the Institute of Molecular Genetics of the Russian Academy of Sciences and share one design strategy, a C-terminal Pro-Gly-Pro extension that protects a short biologically active message fragment from rapid enzymatic degradation, and both are registered as nasal preparations in the Russian Federation while holding no marketing authorisation from the MHRA, EMA or FDA. Because the two molecular weights differ by only 62 g/mol, the 10+10 vial is close to equimolar, roughly 13.3 µmol of Selank against 12.3 µmol of Semax. The blend itself has no dedicated literature; the evidence base is two separate single-compound literatures. Supplied as lyophilised powder, supplier-tested, with the certificate published on this page and independent third-party verification pending. In-vitro laboratory research use only.

Selank + Semax vs the Components Alone

The two components are the flagship peptides of one design programme, and pairing them in a single vial suits the way the literature already treats them. Selank carries tuftsin as its protected message fragment, and its evidence base is weighted towards anxiety and stress-response models, GABAergic neurotransmission and enkephalin stabilisation. Semax carries the Met-Glu-His-Phe core of ACTH(4-10), and its evidence base is weighted towards neurotrophin expression, BDNF and trkB signalling, and cerebral ischaemia models. The shared Pro-Gly-Pro tail means the two control for one another's stabilisation chemistry, which is why combined designs are common in the Russian literature from which both compounds come. The honest caveat is that no controlled study has evaluated this specific co-formulation: every mechanistic claim traces to one component or the other, never to the mixture. And because co-lyophilisation fixes the ratio permanently at reconstitution, any design needing independent concentrations, a single-compound control arm or attribution of an observed effect to one mechanism requires the individual vials, which we stock separately.

Selank + Semax Research Applications

The blend is used in preclinical designs that would otherwise run the two compounds from separate preparations: combined anxiety-and-cognition protocols in rodent behavioural models, GABAergic and neurotrophin endpoint work where both mechanisms are measured in one animal cohort, and gene-expression screens comparing the two compounds' transcriptional signatures. The practical value of the co-formulated vial is procedural, one reconstitution, one fill volume, one in-use window and one certificate of analysis, rather than any property arising from the mixture itself. The component literatures remain the reference points: enkephalinase inhibition and GABAergic gene expression on the Selank side, BDNF and trkB upregulation and ischaemia models on the Semax side. Researchers needing to vary the ratio, run either compound alone as a control, or assign an observed response to one molecule should use the individual vials instead.

Reconstitution Guide

Treat the vial as a single 20mg preparation with one fill volume set by the concentration your protocol specifies. Allow the vial and the bacteriostatic water to reach room temperature, then sterilise both rubber stoppers with an alcohol swab. Inject the bacteriostatic water slowly down the inner glass wall of the vial, never directly onto the lyophilised powder, and swirl gently in a slow circular motion until fully dissolved. Never shake or vortex. Handle the blend to the standard of its more fragile component: the N-terminal methionine of Semax is the oxidation-sensitive residue in this pairing, so keep stopper-open time and headspace air to a minimum and reconstitute away from strong light. The solution should be clear and colourless. Remember that the components cannot be separated after reconstitution and that the equal-mass blend is close to equimolar, roughly 13.3 µmol of Selank against 12.3 µmol of Semax. Label the vial with the fill volume, concentration and reconstitution date, and refrigerate immediately.

See our full peptide reconstitution guide and reconstitution calculator for step-by-step protocol.

Storage Instructions

Lyophilised vials should be stored at -20°C, protected from light and moisture, and remain stable for up to 24 months. Once reconstituted with bacteriostatic water, store the solution at 2-8°C and use within approximately 4 weeks, preparing single-use aliquots at -20°C for anything longer. Because both components share one reconstitution date in a co-formulated vial, the less stable component governs the whole preparation: methionine oxidation in the Semax component is the degradation route to watch, accelerated by dissolved oxygen, light and repeated freeze-thaw cycling, while the methionine-free, proline-rich Selank backbone is comparatively robust. Aliquot at reconstitution rather than repeatedly puncturing one stock, and handle under sterile laboratory conditions throughout.

Frequently Asked Questions

Research References

• Selank inhibits enkephalin-degrading enzymes (Zozulya et al., Bull Exp Biol Med, 2001)
• Selank affects gene expression in GABAergic neurotransmission (Volkova et al., Front Pharmacol, 2016)
• Semax regulates BDNF and trkB expression in rat hippocampus (Dolotov et al., Brain Res, 2006)
• Neuroprotective effects of Semax in experimental cerebral infarction (Romanova et al., Bull Exp Biol Med, 2006)

Related Research Compounds

• → Selank 10mg
• → Semax 10mg
• → Bacteriostatic Water 10ml