Selank + Semax

Each peptide has its own evidence base. Selank work centres on enkephalin-degrading enzymes and GABAergic gene expression. Semax work centres on BDNF and trkB signalling and ischaemia models. One study measured both side by side (Kost et al., Bioorg Khim, 2001). In human serum, Semax inhibited enkephalin-degrading enzymes with an IC50 of 10 µM and Selank with 20 µM. No controlled study has tested the co-formulated mixture. Once dissolved the ratio is fixed, so designs needing independent concentrations, a single-peptide control or attribution to one mechanism need the separate vials.

This is the pre-blended presentation, a single lyophilised vial containing Selank 10mg and Semax 10mg. The blend pairs two Russian-developed nootropic heptapeptides: Selank, a synthetic analogue of the immunoglobulin-derived tetrapeptide tuftsin (Thr-Lys-Pro-Arg-Pro-Gly-Pro, 751.9 g/mol, CAS 129954-34-3), and Semax, a synthetic analogue of the ACTH(4-10) fragment (Met-Glu-His-Phe-Pro-Gly-Pro, 813.7 g/mol, CAS 80714-61-0). Both have been studied for anxiolytic and cognitive effects in animal models and early human research, with the Selank literature weighted towards anxiety-related mechanisms and the Semax literature towards neurotrophin biology and neuroprotection.\n\nBoth compounds share a design origin, the Institute of Molecular Genetics of the Russian Academy of Sciences, and one stabilisation strategy: a C-terminal Pro-Gly-Pro extension protecting a short active fragment from rapid enzymatic degradation. That shared chemistry is why they are so often studied side by side, and why a co-formulated vial is a natural format for designs running both. What the blend as a format gives is procedural: one vial means one reconstitution, one fill volume, one solution and one in-use window, removing a transfer step along with its sterility and volumetric error. What it removes is independent control. The two components cannot be separated after reconstitution, and an equal-mass blend is not automatically equimolar, though the arithmetic here is unusually forgiving. The two molecular weights differ by only 62 g/mol, so 10mg of each corresponds to roughly 13.3 µmol of Selank against 12.3 µmol of Semax, close to a true 1:1 molar ratio.\n\nThe honest position on the pairing is that no controlled study has evaluated this specific combination, and the blend should be treated as two separate compounds in one container. Each component carries its own literature: Selank has been reported to inhibit enkephalin-degrading enzymes (Zozulya et al., Bull Exp Biol Med, 2001) and to alter the expression of GABAergic neurotransmission genes in rat brain (Volkova et al., Front Pharmacol, 2016), while Semax has been reported to upregulate hippocampal BDNF and trkB (Dolotov et al., Brain Res, 2006) and to reduce infarct volume in a rat model of focal cerebral ischaemia (Romanova et al., Bull Exp Biol Med, 2006). The primary literature for both compounds is largely Russian in origin and lacks extensive independent Western replication, and neither compound holds a marketing authorisation from the MHRA, EMA or FDA. In-vitro laboratory research use only.