Semax

Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro (MEHFPGP). It is derived from the ACTH(4-10) fragment with an added C-terminal Pro-Gly-Pro extension that confers proteolytic stability. It was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences and is supplied for in vitro research use only.

Semax is structurally derived from the 4-10 fragment of adrenocorticotropic hormone (ACTH) but lacks the corticotropic activity of full-length ACTH. Preclinical literature describes it as a non-corticotropic ACTH analog with retained central nervous system effects, often studied as a melanocortin-pathway-adjacent research tool.

Multiple rodent studies report Semax rapidly upregulates Bdnf and Ngf mRNA in the hippocampus and frontal cortex, with elevated mature BDNF protein in basal forebrain. Shadrina et al. (2010, PMID 19662538) and Dolotov et al. (2006, PMID 16635254) are key references for the neurotrophin pathway findings.

Semax has been investigated in cultured hippocampal neurons against glutamate excitotoxicity (Storozhevykh 2007, PMID 17760984), in rodent middle cerebral artery occlusion models of ischemia, and in oxidative-stress paradigms. It is reported to reduce ROS, attenuate calcium dysregulation, and modulate inflammatory gene expression in preclinical settings.

Lyophilized Semax should be stored at -20°C for long-term stability. Once reconstituted with bacteriostatic water, it should be refrigerated at 2-8°C and used within 14 days. Avoid repeated freeze-thaw cycles and protect from light. For in vitro research use only — not for human or veterinary administration.

The C-terminal Pro-Gly-Pro tripeptide is added to the natural ACTH(4-10) sequence to dramatically slow enzymatic degradation by aminopeptidases and endopeptidases. This proteolytic stability extends the duration of CNS activity in preclinical models compared to the parent ACTH(4-10) fragment alone.