Semax
ACTH 4-10 analog / Heptapeptide Semax
Semax is a synthetic heptapeptide analog of the ACTH(4-10) fragment, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences as a neuroprotective and nootropic agent. It is approved in Russia and Ukraine for the treatment of stroke, transient ischemic attacks, cognitive disorders, optic nerve atrophy, and peptic ulcers. Semax enhances BDNF expression, modulates serotonergic and dopaminergic neurotransmission, and provides neuroprotection without any hormonal (adrenocorticotropic) activity despite its ACTH-derived structure.
Mechanism of Action
Synthetic analog of ACTH 4-10 fragment with a Pro-Gly-Pro C-terminal extension. Increases BDNF and NGF expression in the hippocampus. Enhances attention, memory, and learning without hormonal effects of full-length ACTH. Neuroprotective against oxidative stress.
Research Protocols
For research purposes only. Not medical advice.
Research protocols use 200-600mcg intranasally 2-3 times daily. Russian approved protocols use 0.1% or 1% nasal drops. Higher concentrations (1%) used for acute neuroprotection. Typical cycles are 2-4 weeks.
Research Notes
Clinical Research Status
Semax has been approved in Russia since 2001 as a nasal spray (0.1% and 1% solutions) for acute ischemic stroke, cognitive impairment, and optic nerve diseases. Large-scale Russian clinical trials involving stroke patients demonstrated reduced neurological deficit scores and improved functional outcomes when administered within 6 hours of ischemic events. It has not entered FDA regulatory pathways and remains unapproved in Western markets. The 1% formulation (N-Acetyl Semax Amidate, or NASA) is used in more severe neurological conditions while the 0.1% is used for cognitive enhancement.
Key Published Findings
A 2005 study in Doklady Biological Sciences showed Semax increased BDNF mRNA expression in the rat hippocampus and basal forebrain by 1.4-3x baseline within 24 hours. Clinical stroke trials published in Zhurnal Nevrologii i Psikhiatrii demonstrated 2.4x faster neurological recovery versus controls when administered acutely. Semax was shown to differentially regulate 24 genes in glial cells related to neuroinflammation and neuroprotection in a 2013 transcriptomics study. Research confirms no adrenocorticotropic effects despite the ACTH backbone, as the melanocortin-receptor binding motif was deliberately excluded from the fragment.
Safety Profile
Extensive clinical use in Russia over 20+ years has revealed no significant adverse effects, hormonal disruption, or organ toxicity. Semax produces no sedation, tolerance, withdrawal, or dependence, and no drug-related deaths have been reported. The peptide is rapidly degraded by aminopeptidases with a plasma half-life of approximately 2 minutes, though CNS effects persist for 20-24 hours due to intracellular signaling cascades. Nasal administration avoids first-pass metabolism and achieves CNS penetration without systemic accumulation.
Drug Interactions & Contraindications
No formally documented drug interactions exist in published literature, though the serotonergic modulation suggests theoretical caution with SSRIs or MAOIs at high doses. Contraindicated in patients with acute psychosis or severe manic episodes due to its stimulating cognitive effects. May theoretically potentiate the effects of stimulant medications (amphetamines, methylphenidate) through dopaminergic enhancement. Not recommended in pregnancy due to insufficient safety data despite the absence of hormonal activity.
Comparison to Related Compounds
Semax is more stimulating and neuroprotective compared to Selank, which is primarily anxiolytic; Russian clinicians frequently prescribe them together for complementary effects. Unlike racetam nootropics, Semax has a well-defined mechanism (BDNF upregulation, TrkB signaling) and documented neuroprotective efficacy in stroke. Compared to cerebrolysin (another Russian-approved neuroprotective), Semax offers non-invasive nasal administration versus required IV infusion. The N-Acetyl Semax Amidate (NASA) analog offers approximately 60x greater stability and potency versus unmodified Semax.
Community Observations
Users report enhanced verbal fluency, motivation, and mental clarity typically within 10-30 minutes of intranasal administration, lasting 4-8 hours. The 0.1% solution (50 mcg/drop) is most commonly used at 2-3 drops per nostril, 2-3 times daily for cognitive enhancement. Some users report a mild stimulant-like quality that can interfere with sleep if dosed too late in the day. Combining Semax with Selank is considered the gold-standard peptide nootropic stack in the biohacking community, providing focused cognition without anxiety.
Half-Life
~2-3 minutes (intranasal effects last 4-6 hours)
Reconstitution
Bacteriostatic water (BAC) for SubQ; saline for nasal
Storage
Lyophilized
Refrigerate 2-8C up to 12 months.
Reconstituted
Refrigerate 2-8C. Use within 14 days.
US Legal Status
Also Known As
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