What Is Semax?
Semax is a heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) and a synthetic analogue of the ACTH(4-7) fragment, with a C-terminal Pro-Gly-Pro extension that confers resistance to enzymatic degradation and improves CNS activity. Originally developed at the Institute of Molecular Genetics in Moscow, it is registered in Russia as a nootropic and neuroprotective agent.
Mechanisms of Action
Semax exerts its effects through several well-characterised pathways:
- BDNF and NGF upregulation — dramatically increases brain-derived neurotrophic factor and nerve growth factor in the hippocampus and frontal cortex; BDNF increases of 4–8× have been reported in preclinical studies
- Melanocortin receptor partial agonism — activates MC4R to modulate attention, motivation, and working memory
- Dopaminergic enhancement — increases dopamine receptor sensitivity and monoamine turnover in prefrontal cortex
- Neuroprotection — antioxidant and anti-apoptotic effects under ischaemic conditions
Key Research Findings
- Stroke recovery: Russian clinical trials demonstrated significant improvements in neurological deficit recovery when administered within 24 hours of ischaemic stroke
- ADHD research: Improvements in attention, working memory, and task-switching in studies with human subjects
- Optic nerve: Clinical evidence of visual field improvement in patients with optic nerve disease
- Anxiety modulation: Unlike pure stimulants, Semax produces motivation and focus without anxiety or cardiovascular stimulation
Research Notes
Semax is typically studied as an intranasal preparation (most efficient CNS delivery). Store lyophilised peptide at −20°C.
Related compounds: Selank, Epithalon.