What it is
Semax is a Russian-developed nootropic peptide based on the ACTH(4-10) sequence. It enhances memory, learning, and mood by raising BDNF and modulating dopaminergic and serotonergic pathways. It also stimulates the brain's default-mode network and offers neuroprotective effects through improved blood flow, mitochondrial stability, and cerebral resilience after ischemic insult.
Mechanism of action
Heptapeptide analog of the N-terminal ACTH(4-10) fragment. Increases BDNF and NGF expression, modulates monoaminergic neurotransmission, and influences immune/vascular gene expression in ischemic brain regions.
Half-life: Short — minutes; intranasal route bypasses first-pass metabolism.
Evidence summary
Approved in Russia for stroke and cognitive disorders. Mechanistic studies show antioxidant action, default-mode network modulation, and post-ischemic gene expression effects supporting neuroprotection.
Typical dosing protocols
- 0.1% nasal spray: 1–2 sprays per nostril, 2–3× daily
- Subcutaneous: 250–1,000 mcg daily, 4-week cycles
- Cycle off for 4 weeks between courses
Side effects & safety
- Generally well-tolerated
- Mild irritability or headache reported
- Long-term Western safety data is limited
Cited studies
- (2024). Semax exhibits antioxidant properties that help protect neurons from oxidative stress. Synapse Drug Intelligence.Read source ↗
- (2018). Effects of Semax on the Default Mode Network of the Brain. NeuroImage / NLM.Read source ↗
- (2014). The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia. Doklady Biochemistry and Biophysics (NLM).Read source ↗
All content is for research and educational purposes. Peptides described are sold for laboratory research use only and are not intended to diagnose, treat, cure, or prevent any disease. Always consult a qualified healthcare professional before beginning any protocol.