Semax

Semax (CAS 80714-61-0; MW 887.0 g/mol; sequence MEHFPGP) is a synthetic 7-amino acid heptapeptide derived from the 4th through 7th amino acids of adrenocorticotropic hormone (ACTH) — the ACTH(4-7) fragment (Met-Glu-His-Phe) — with a C-terminal Pro-Gly-Pro tripeptide extension appended to confer enzymatic resistance against proteolytic degradation, substantially extending biologically active half-life while preserving nootropic properties without ACTH's adrenocortical hormonal activity.

Semax has undergone extensive clinical investigation in Russia, where it is approved as a nootropic and neuroprotective medication for ischemic stroke sequelae, transient ischemic attacks, and cognitive impairment states — providing a richer translational context than purely experimental compounds.

The primary and best-characterized mechanism is BDNF (Brain-Derived Neurotrophic Factor) upregulation. Multiple research and clinical studies document Semax's ability to rapidly and substantially increase BDNF expression and its high-affinity receptor TrkB in cortical, hippocampal, and striatal brain regions. BDNF is essential for synaptic plasticity, long-term potentiation, learning and memory consolidation, and neuronal survival under stress.

Simultaneously, Semax upregulates NGF and activates dopaminergic, serotonergic, and cholinergic neurotransmitter systems — producing measurable improvements in attention, memory encoding, and cognitive speed in research model and human studies.

In neuroprotection research, Semax has demonstrated significant efficacy in research subject ischemia/reperfusion models, reducing infarct volume, improving neurological deficit scores, and enhancing post-ischemic recovery. The 25mg vial format reflects Semax research utility in extended protocols, multi-animal studies, and intranasal delivery model preparation.