Neuroscience · Semax & Selank
Semax and Selank: short regulatory peptides in rodent neuroscience
October 2, 2026 · 1 min read · Models: Rat
Semax and Selank are heptapeptides developed in Russia from ACTH(4–10) and tuftsin respectively, each extended with a stabilizing Pro-Gly-Pro tail. Rodent studies report changes in BDNF expression (Semax) and in anxiety-related behavior and monoamine signaling (Selank).
A summary of published research for scientific reference. It is not medical advice and does not describe or endorse use in humans or animals. Findings from cell culture and animal models often do not carry over to other systems.
Design
Both peptides came from the Institute of Molecular Genetics in Moscow. Semax (Met-Glu-His-Phe-Pro-Gly-Pro) combines the ACTH(4–7) fragment with a C-terminal Pro-Gly-Pro tripeptide, which slows degradation. Selank (Thr-Lys-Pro-Arg-Pro-Gly-Pro) applies the same strategy to tuftsin, an immunomodulatory tetrapeptide from the IgG heavy chain.
Semax in rodent studies
Dolotov and colleagues (Brain Research, 2006) reported that Semax increased BDNF and TrkB expression in the rat hippocampus, alongside changes in a conditioned avoidance task. Other rat studies examined gene-expression changes after experimental cerebral ischemia.
Selank in rodent studies
Rat studies of Selank report changes in elevated plus-maze and open-field behavior in certain strains. They also report changes in serotonin metabolism, GABAergic gene expression and enkephalinase activity.
Evidence base
Most studies come from a small number of Russian groups and are not widely replicated in international literature. Mechanisms at the receptor level are not well defined, which makes both peptides interesting but under-characterized research subjects.
References
- Dolotov OV, Karpenko EA, Inozemtseva LS, et al. Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus. Brain Res. 2006;1117(1):54–60.