Semax + Selank

Semax — neurotrophic and monoaminergic research

Semax was derived from ACTH(4–10) by adding Pro-Gly-Pro to the C-terminus, a modification that eliminates adrenal stimulation while extending the peptide's half-life in plasma. Rodent studies have reported increased BDNF and NGF expression, changes in TrkB receptor signalling and altered dopaminergic and serotonergic turnover in the hippocampus and frontal cortex after administration. Behavioural work has examined attention, learning-acquisition and memory-retention tasks, and ischaemia models have been used to look at neuronal survival endpoints. Much of the primary literature is Russian-language and heterogeneous in design.

Selank — GABAergic and stress-response research

Why the two are studied together

• Complementary mechanisms — neurotrophic signalling versus inhibitory and stress-axis modulation.
• Similar physical chemistry — both are small, water-soluble heptapeptides sharing the Pro-Gly-Pro motif, so they co-lyophilize and reconstitute cleanly together.
• Overlapping model systems — attention, memory and stress paradigms often measure endpoints relevant to both peptides.

What a blend does and does not resolve

A fixed 1:1 vial removes weighing error between two components and simplifies handling, but it also fixes the ratio. Studies designed to separate the contribution of each peptide, or to vary their proportion, need the single-compound vials rather than the blend. Investigators frequently run the blend alongside Semax-alone and Selank-alone arms for this reason.

Evidence limits

Store the sealed vial at −20 °C and let it reach room temperature before opening so condensation does not settle on the cake. Reconstitute by running bacteriostatic water slowly down the inner vial wall rather than directly onto the powder, then swirl gently — never vortex or shake, since mechanical shear and foaming can denature short peptides. Both components dissolve readily in water; the solution should be clear and colourless. Label the vial with peptide identity, concentration, solvent and date, refrigerate at 2–8 °C, keep it out of light, and avoid repeated freeze-thaw cycles by aliquoting if the study runs over multiple sessions. Handle with gloves under standard good laboratory practice.