Semax and Selank share an origin and a structural trick. Both were developed at the Institute of Molecular Genetics in Russia, and both take a short endogenous peptide sequence and extend it with a Pro-Gly-Pro tail to resist enzymatic degradation.
Semax
Semax is based on the ACTH(4-10) fragment. The Pro-Gly-Pro extension increases stability while removing the hormonal activity of the parent sequence — it does not stimulate cortisol release the way intact ACTH does.
Research has examined semax in relation to brain-derived neurotrophic factor and nerve growth factor expression, dopaminergic and serotonergic modulation, neuroprotection in ischaemia models, and measures of attention and memory consolidation.
Selank
Selank is based on tuftsin, an endogenous immunomodulatory peptide, similarly extended with Pro-Gly-Pro.
Studies have examined GABAergic and serotonergic signalling, BDNF expression, and anxiolytic activity. A recurring observation in the literature is the absence of the sedation and dependence associated with benzodiazepine anxiolytics.
A note on the evidence base
Much of the clinical literature on both compounds is Russian, and a portion of it is not available in English translation or indexed in the databases Western researchers typically search. This matters when assessing the strength of the evidence: the volume of published work is larger than a PubMed search suggests, but the methodological standards vary and independent replication is limited.
Handling and availability
Both are supplied as lyophilised powder in factory-sealed vials, stored at −20 °C and protected from light. Space Pep supplies Semax and Selank in Egypt. See the full cognition and mood collection.
All products supplied by Space Pep are intended strictly for laboratory research purposes. They are not drugs, foods, cosmetics, or medical devices, and are not intended to diagnose, treat, cure, or prevent any disease.