What is Semax?
Semax is a synthetic heptapeptide based on the 4–7 residues of ACTH(4-10) with a C-terminal Pro-Gly-Pro extension that stabilizes it against enzymatic degradation. Developed in Russia in the 1980s, it has been studied and used clinically in Eastern Europe for stroke recovery, optic nerve disorders, and cognitive enhancement. It acts rapidly via intranasal administration, engaging multiple neurotrophic and neurotransmitter systems. Researchers have studied its effects on BDNF expression, dopaminergic tone, and serotonergic signaling.
Mechanism of action
Semax does not bind the classical ACTH receptor at research doses. Instead, preclinical data indicates it modulates brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) expression, enhances dopamine and serotonin activity in prefrontal circuits, and upregulates the expression of genes involved in oxidative stress resistance and neuronal survival. Its very short serum half-life belies prolonged receptor-level effects attributed to downstream signaling cascades.
Researched benefits
- Enhanced working memory and attention in rodent cognitive models
- BDNF and NGF upregulation in hippocampal and prefrontal cortex tissue
- Neuroprotective effects following ischemic injury in animal stroke models
- Improved visual acuity in clinical studies of optic nerve degeneration (Russia)
- Anxiolytic-like effects without sedation in rodent anxiety paradigms
Researched dosage
Most research protocols use 200–600 mcg administered 2× per day via nasal injection. Semax is most commonly administered intranasally (1–2 drops per nostril of a 0.1% or 1% solution). Research protocols typically use 200–600 mcg per dose, one to two times daily. Injectable formulations also exist but are less common in research settings outside clinical trials.
A typical cycle runs 4 weeks on, then 2 weeks off before reassessment.
Use the calculator below to convert your target Semax dose into exact insulin-syringe units.
Reconstitution & storage
A standard 0.5 mg vial reconstituted with 1 mL of bacteriostatic water yields 500 mcg/mL. Semax solution should be refrigerated at 2–8°C and protected from light. Lyophilized powder is stable at room temperature short-term; reconstituted solution should be used within 30 days when refrigerated.
Side effects & considerations
- Mild nasal irritation or stinging with intranasal administration
- Transient stimulant-like effects (increased alertness, possible restlessness at higher doses)
- Mild anxiety or agitation in some users, particularly at higher doses
- Headache reported occasionally in research participants
Semax stacks
- Cognitive Enhancement Protocol — paired with Selank. Balanced cognitive stimulation and anxiolytic modulation. Semax (excitatory, BDNF-upregulating) is frequently paired with Selank (anxiolytic, GABAergic modulation) in cognitive research to combine focus enhancement with anxiety reduction.
- Neuroprotection & Recovery — paired with BPC-157. Central and peripheral neuroprotective signaling. Researchers have theorized combining Semax's central BDNF-driven neuroprotection with BPC-157's peripheral and gut-brain axis effects for comprehensive neurological recovery models.
Selected research
- Semax, an ACTH(4-10) analogue, protects against neurodegeneration — Journal of Neurochemistry, 2003
- Semax increases BDNF expression in the cerebral cortex of rats — Bulletin of Experimental Biology and Medicine, 2005
- Effect of Semax on optic nerve disorders: a clinical study — Vestnik Oftalmologii, 2007