Semax
Cognitive & MoodAlso known as: Semax, ACTH(4-7)-PGP
Mechanism
Semax is a synthetic brain-boosting peptide based on a fragment of the stress hormone ACTH, designed to enhance memory, focus, and mental clarity. It works by increasing the production of brain-derived growth factors that support neuron health and improve how brain cells communicate with each other. It has also been studied for stroke recovery, where it may help protect brain tissue from damage.
Technical detail
Semax is a synthetic heptapeptide consisting of the ACTH(4-7) fragment (Met-Glu-His-Phe) with a C-terminal Pro-Gly-Pro tripeptide that increases resistance to enzymatic degradation. It upregulates BDNF and NGF expression via TrkB receptor signaling, enhances dopaminergic and serotonergic neurotransmission, and modulates the expression of immediate early genes (c-Fos, NGFI-A) involved in synaptic plasticity. Semax also demonstrates neuroprotective effects through inhibition of nitric oxide synthase and attenuation of oxidative stress cascades in ischemic brain tissue.
Effects
## Detailed Effects — Semax ### Central Nervous System — Nootropic / Cognitive Enhancement [Tier 1 (Russia), Tier 2 (International)] - Synthetic heptapeptide: ACTH(4-7) fragment (Met-Glu-His-Phe) with C-terminal Pro-Gly-Pro for enzymatic stability and enhanced CNS penetration. - Primary mechanism: potent upregulation of BDNF and NGF via TrkB receptor signaling cascade — increases neurotrophin levels in hippocampus, cortex, and basal forebrain within hours of administration. - Enhances dopaminergic neurotransmission — increases dopamine and dopamine metabolite (DOPAC, HVA) levels in prefrontal cortex and striatum. This underlies the focus, motivation, and mental energy effects. - Enhances serotonergic neurotransmission — modulates 5-HT turnover, contributing to mood stabilization. - Modulates immediate early gene expression (c-Fos, NGFI-A, Arc) — markers of synaptic plasticity and memory consolidation. - **Neuroprotective effects**: Inhibits neuronal nitric oxide synthase (nNOS), attenuates oxidative stress, reduces excitotoxic glutamate damage. Demonstrated protection in animal stroke and TBI models. - **Human studies** (Russian): Approved for cognitive disorders (dyscirculatory encephalopathy), stroke recovery, optic nerve atrophy, and as a nootropic. Multiple human trials showing improved cognitive function, attention, and memory. - **Stroke recovery**: Administered intranasally within hours to days of acute ischemic stroke — improved neurological outcomes in Russian clinical studies. Approved at 1% concentration for stroke (vs 0.1% for nootropic use). ### Central Nervous System — Attention & Focus [Tier 2] - Dopaminergic enhancement in the prefrontal cortex improves sustained attention, working memory, and executive function. - Users consistently report improved mental clarity, motivation, and ability to focus on complex tasks. - Unlike stimulants (amphetamines, methylphenidate), Semax does not produce peripheral sympathomimetic effects — no tachycardia, hypertension, or appetite suppression. ### Immune System [Tier 2] - Modulates inflammatory cytokine expression. - May enhance innate immunity through macrophage activation. ### Ophthalmologic [Tier 2] - Approved in Russia for optic nerve atrophy and glaucoma — neuroprotective effects on retinal ganglion cells via BDNF upregulation. - Administered as eye drops (0.1% solution).
Practitioner Guide
## Practitioner Guide — Semax ### Regulatory Status - **Approved in Russia** as a nootropic (0.1% solution) and for stroke recovery (1% solution) since the 1990s. One of the most widely prescribed peptides in Russian neurology. - NOT FDA-approved. Available internationally as a research peptide (nasal spray or lyophilized powder). - N-Acetyl Semax and N-Acetyl Semax Amidate versions available from research peptide suppliers. ### Forms & Comparative Pharmacology **Standard Semax (0.1% Solution)** - The original nootropic form. Each drop ~50 mcg. Standard dose: 2-3 drops per nostril, 2-3x daily (200-900 mcg/day). - Clinically studied form. Well-characterized pharmacology. - Half-life: short (minutes), but CNS effects persist 4-8 hours due to downstream gene expression changes. **Semax 1% Solution** - 10x concentration of the standard form. Used for acute stroke and severe neurological conditions in Russia. - Dose: 2-3 drops per nostril, 3-4x daily (2,000-6,000 mcg/day). - More potent and sustained effects. Some practitioners use this concentration for intensive cognitive enhancement courses. **N-Acetyl Semax** - N-terminal acetylation increases aminopeptidase resistance → extended half-life. - Anecdotally more potent than standard Semax on a per-mcg basis. - Stronger dopaminergic effects reported — more pronounced focus and motivation. - Popular among biohackers who want enhanced stimulatory cognitive effects. **N-Acetyl Semax Amidate (NASA)** - N-terminal acetylation + C-terminal amidation — dual modifications for maximum enzymatic stability. - Significantly longer duration of action. Some users report 6-10+ hours of cognitive effects from a single dose. - Anecdotally reported as the most potent form available — described as producing a "clean, sustained mental energy" without jitteriness. - Many experienced users consider NASA the definitive form of Semax. - Downside: furthest from the clinically studied molecule. Theoretical changes in receptor selectivity cannot be ruled out. - Some users report it is "too stimulating" — can cause restlessness or insomnia if dosed in the afternoon/evening. ### Dosing Protocols **Standard Semax (Nasal Spray)** - **Nootropic dose**: 200-600 mcg intranasal, 2-3 times daily. - **Intensive/neurorecovery dose**: 600-1,200 mcg intranasal, 2-3 times daily. - **Course duration**: 10-30 days. Standard course in Russia: 10 days for nootropic, 14-21 days for stroke recovery. - Best administered in the morning and early afternoon — avoid evening dosing due to stimulatory effects that may impair sleep. **N-Acetyl Semax Amidate (Nasal Spray)** - 200-600 mcg per nostril (400-1,200 mcg total), 1-2 times daily. - Due to extended duration, many users find once-daily morning dosing sufficient. - Start low (200 mcg per nostril, once daily) and titrate up — this form can be quite stimulating. - **DO NOT dose after 2 PM** unless you want to stay up late. - Cycle: 20-30 days ON, 10-14 days OFF. ### Cycling Protocols - **Standard course**: 10-14 days ON, 10-14 days OFF. This is the Russian clinical standard. - **Extended course**: 30 days ON, 14-21 days OFF (for chronic cognitive optimization). - **As-needed**: Single doses for demanding cognitive tasks (exams, presentations, creative work). No cycling needed for occasional use. - **Continuous use**: Some users run Semax or NASA continuously with 1-week breaks every 6-8 weeks. No dependence reported, but periodic breaks are recommended to maintain sensitivity. - **IMPORTANT**: Semax courses should ideally not exceed 30 continuous days without a break. The Russian prescribing information recommends 10-14 day courses. ### Stacking Combinations **Classic Selank + Semax Stack (The Gold Standard)** - Semax 600-900 mcg intranasal (focus, energy, BDNF) - + Selank 400-800 mcg intranasal (calm, anxiety reduction, BDNF) - Administer Selank first, wait 5 minutes, then Semax. - This is the most widely used nootropic peptide combination worldwide. Selank provides the calm foundation, Semax provides the drive and clarity. - Together they upregulate BDNF through complementary pathways. **Semax + Cerebrolysin Stack (Deep Neurorehab)** - Semax 900-1,200 mcg intranasal daily - + Cerebrolysin 10-30 mL IV/IM daily - For post-stroke, post-TBI, or advanced cognitive decline. - The Cerebrolysin provides broad neurotrophic factors, Semax adds targeted BDNF/dopamine upregulation. - Run 10-20 day courses with clinical supervision. **Semax + Nootropic Supplement Stack** - Semax 600 mcg intranasal AM - + CDP-choline (Citicoline) 500 mg BID (acetylcholine precursor — supports cholinergic function) - + Bacopa monnieri 300 mg daily (memory consolidation) - + Omega-3 2-4 g daily (neuronal membrane support) - Foundational cognitive optimization stack. Can run for 30-day courses. **Work/Productivity Stack (Biohacker Favorite)** - N-Acetyl Semax Amidate 400-600 mcg intranasal AM - + Selank 400 mcg intranasal AM - + Caffeine 100-200 mg (after peptides absorb, ~30 min later) - + L-theanine 200 mg (takes the edge off caffeine jitteriness) - Popular for demanding workdays. ### What Experienced Users Report - **Mental clarity and focus**: Described as a "clean stimulation" — enhanced focus without jitteriness or anxiety. Like "caffeine without the side effects but stronger." - **Verbal fluency**: Words come more easily, conversation flows, writing is more fluid. - **Motivation and drive**: Enhanced dopaminergic tone produces increased motivation for work and tasks. - **Memory**: Improved recall and ability to learn new material. - **Mood**: Mild to moderate mood elevation — not euphoric, just "better baseline." - **Creativity**: Some users report enhanced creative thinking, though this is less consistent than focus effects. - **Onset**: 10-30 minutes intranasally. Effects peak at 1-2 hours. - **Duration**: Standard Semax 3-5 hours, N-Acetyl Semax 4-6 hours, N-Acetyl Semax Amidate 6-10 hours. - **Side effects**: Rarely reported. Occasional nasal irritation, headache at high doses, insomnia if dosed too late. - **No withdrawal or dependence**: Consistent across clinical data and thousands of anecdotal reports. ### Storage & Reconstitution - **Premade nasal spray**: Refrigerate (2-8°C). Use within 30-60 days. - **Lyophilized powder**: Store at -20°C. Reconstitute with bacteriostatic water or sterile water. Refrigerate after reconstitution. - **Nasal spray preparation**: Typical concentration 200-500 mcg per 0.1 mL spray. Use metered-dose nasal spray bottles. - Semax is sensitive to light and heat — keep refrigerated and away from direct light. ### Nasal Spray Administration Tips - Blow nose gently before administration to clear passages. - Tilt head slightly forward (not backward — you want the spray on the nasal mucosa, not dripping down the throat). - Spray into one nostril while gently occluding the other. - Sniff gently — do NOT sniff hard (drives solution to the throat, reducing nasal mucosal absorption). - Wait 5 minutes before administering any other nasal peptide (Selank). - Do NOT blow nose for at least 10-15 minutes after administration.
Dosing Protocols
- Dose
- 200mcg
- Frequency
- 1-2x daily
- Timing
- Morning and optionally early afternoon; avoid evening dosing
- Route
- intranasal
- Cycle
- 4-12 weeks
BDNF upregulation is most beneficial during waking hours when cognitive demands are highest; morning dosing aligns with natural cortisol peak
- Dose
- 600mcg
- Frequency
- 1-2x daily
- Timing
- Morning and optionally early afternoon; avoid evening dosing
- Route
- intranasal
- Cycle
- 4-12 weeks
Higher dose for experienced users seeking stronger nootropic effect; split dosing maintains steady-state levels
Contraindications & Cautions
- hard stop — PregnancyNo adequate human safety data during pregnancy. Neuroactive peptide with BDNF-modulating activity poses theoretical risk to fetal neurodevelopment.Action: Do not use during pregnancy. Discontinue if pregnancy is detected.
- hard stop — BreastfeedingNo data on excretion in breast milk. Neuroactive peptide exposure in nursing infant poses unknown risk.Action: Do not use while breastfeeding.
- hard stop — Under 18 years of agePeptide protocols are not designed for pediatric use. Neuroactive peptide with BDNF-modulating effects on developing brain unknown.Action: Do not provide peptide protocols to individuals under 18.
Evidence
- moderate
Glazova NY, Manchenko DM, Volodina MA, Merchieva SA, Andreeva LA, Kudrin VS, Myasoedov NF, Levitskaya NG (2021) — Neuropeptides — PMID: 33418449
Semax administration reduced anxiety-like behavior, improved learning, and normalized brain biogenic amines disrupted by early-life SSRI (fluvoxamine) exposure. Demonstrated neuroprotective effect against serotonin system disruption during development. Supports Semax as modulator of anxiety-related monoamine systems.
- moderate
Functional Connectomic Approach to Studying Selank and Semax Effects
Panikratova YR, Lebedeva IS, Sokolov OY, Rumshiskaya AD, Kupriyanov DA, Kost NV, Myasoedov NF (2020) — Dokl Biol Sci — PMID: 32342318
Selank and Semax both altered resting-state fMRI functional connectivity between right amygdala and temporal cortex within 20 minutes of intranasal administration in 52 healthy participants. Each peptide showed distinct connectivity patterns — Selank predominantly anxiolytic (amygdala-focused); Semax more prefrontal/executive (DLPFC). First direct neuroimaging evidence of distinct mechanisms.
- moderate
Levitskaia NG, Vilenskii DA, Sebentsova EA, Andreeva LA, Kamenskii AA, Miasoedov NF (2010) — Izv Akad Nauk Ser Biol — PMID: 20387390
Intranasal Semax (50-500 mcg/kg) normalized anxiety and depression behaviors elevated by cholecystokinin-tetrapeptide (CCK-4). No effect on baseline emotional state in normal rats. Anxiolytic and antidepressant effects observed specifically at elevated anxiety levels — suggests condition-specific activation rather than general sedation.
- moderate
Semax (ACTH 4-10 analogue) as a cognitive enhancer: neuroprotective and nootropic effects
Ashmarin IP, Nezavibatko VN, Levitskaya NG, Koshelev VB, Kamensky AA (1997) — CNS Drug Reviews
Semax (Met-Glu-His-Phe-Pro-Gly-Pro), a synthetic ACTH(4-10) analogue, demonstrated nootropic and neuroprotective effects in clinical studies. Improved attention, memory, and cognitive processing in healthy volunteers and patients with cognitive decline. Also showed benefit in acute ischemic stroke recovery. Approved in Russia as nootropic nasal spray. Mechanism involves BDNF upregulation and modulation of dopaminergic and serotonergic neurotransmission.
Stacks featuring this peptide
The classic Russian nootropic duo. Semax (ACTH 4-10 analog) directly enhances focus, memory consolidation, and BDNF expression in the hippocampus and prefrontal cortex. Selank (tuftsin analog) reduces anxiety and mental noise via GABAergic modulation and enkephalin stabilization — clearing the cognitive runway for Semax to work. The combination addresses both sides of cognitive performance: the "accelerator" (Semax for focus and processing speed) and the "brake release" (Selank for anxiety reduction). Both are intranasal, both are approved medications in Russia with extensive safety data.
For individuals concerned about cognitive decline, TBI recovery, or neurodegenerative disease prevention. Cerebrolysin is a multi-neurotrophic peptide complex that mimics BDNF, NGF, GDNF, and CNTF — promoting synaptic remodeling, neuronal sprouting, and neuroprotection (approved in 40+ countries, Cochrane-reviewed for stroke and Alzheimer's). Semax (ACTH 4-10 analog) acutely enhances BDNF expression in the hippocampus and prefrontal cortex for memory and focus. Humanin (mitochondrial-derived peptide) protects neurons from amyloid-beta toxicity and mitochondrial apoptosis — the two primary drivers of Alzheimer's. Pinealon normalizes circadian rhythm and melatonin secretion, which is critical for brain waste clearance via the glymphatic system during sleep.
Selank and Semax target complementary pathways in the brain. Semax increases BDNF and modulates serotonergic and dopaminergic systems, enhancing focus, memory formation, and neuroplasticity. Selank acts on GABAergic pathways to reduce anxiety while also modulating IL-6 and other inflammatory cytokines in the CNS. Together they provide a calm-focus state — enhanced cognitive performance without the jitteriness of stimulants.
Selank (anxiolytic + cognitive via tuftsin/GABA modulation) + Semax (nootropic + BDNF via ACTH fragment activity) + Cerebrolysin (neurotrophic cocktail mimicking NGF/BDNF/GDNF). Selank addresses anxiety that impairs cognition, Semax directly enhances focus and memory, Cerebrolysin provides long-term neuroprotection and synaptic remodeling.
Research Summary
## Research Summary — Semax ### Tier 1: Randomized Controlled Trials - **Multiple Russian RCTs (1990s-2020s)**: Semax approved in Russia based on extensive clinical trial program. Studies showed: - Improved cognitive function in dyscirculatory encephalopathy (Tier 1, multiple trials). - Improved neurological outcomes in acute ischemic stroke when administered intranasally within 6-12 hours (1% solution). - Improved visual outcomes in optic nerve atrophy and glaucoma. - Cognitive enhancement in healthy volunteers (improved attention, memory, information processing). - **Dolotov et al., Neurosci Lett 2006**: Semax increased BDNF mRNA expression in rat hippocampus and cortex within 30 minutes — direct evidence for the neurotrophic mechanism. - **Levitskaya et al., Neurosci Behav Physiol 2008**: Semax modulated dopamine and serotonin metabolism in the striatum and cortex — confirming the dopaminergic enhancement mechanism. ### Tier 2: Systematic Reviews & Key Studies - **Ashmarin et al., Neurosci Behav Physiol 2005**: Comprehensive review of ACTH(4-7) analogs including Semax — characterized the melanocortin-derived nootropic peptide class. - Extensive Russian neuropharmacology literature characterizing Semax's multimodal mechanism: BDNF upregulation, dopaminergic enhancement, neuroprotection, and immune modulation. - Over 100 published studies on Semax (primarily Russian literature, many translated to English). ### Tier 3: Case Reports & Practitioner Protocols - Semax is one of the most widely used nootropic peptides globally — thousands of user experience reports. - Consistently rated among the top nootropic peptides alongside Selank and Cerebrolysin by practitioners and biohackers. - The Semax + Selank combination is considered the foundational nootropic peptide stack. - N-Acetyl Semax Amidate is reported as the most potent and longest-lasting form by experienced users, though it lacks independent clinical study. - Practitioners report it is particularly effective for: work productivity, studying, creative work, post-concussion cognitive rehab, and ADHD-like cognitive patterns (inattention, poor working memory). ### Gaps - Russian clinical data not fully accessible or replicated in Western settings. - N-Acetyl and N-Acetyl Amidate forms have no clinical trial data. - Head-to-head comparison with established nootropics (modafinil, methylphenidate) not conducted. - Long-term safety data (>5 years) limited. - Dose-response relationship in healthy humans not formally characterized. - No FDA IND or NDA filing — unclear if Semax will ever enter the US regulatory pathway. ### Active Trials - No trials currently registered on ClinicalTrials.gov. - Russian academic institutions continue research. - Growing interest in ACTH-derived peptides in Western academic neuroscience.