Semax Research Overview (also known as ACTH 4-7 PGP, Semax nootropic, Met-Glu-His-Phe-Pro-Gly-Pro)
A synthetic heptapeptide derived from ACTH (4-10) developed in Russia with extensive research history. Studied for BDNF upregulation, cognitive enhancement, memory and focus improvement, neurological recovery, and stress resilience. One of the most well-characterized nootropic peptides in the preclinical literature.
For broader research context on nootropic compounds, including comparative stacks, cycling considerations, and interaction notes, see the Complete Nootropic Cheat Sheet.
For the FDA advisory panel discussion of Semax, see FDA Advisory Panel Day 2 Results: Semax and Epitalon Recommended, Emideltide Rejected.
What Is Semax?
Semax is a synthetic heptapeptide (Met-Glu-His-Phe-Pro-Gly-Pro) derived from the N-terminal ACTH 4-10 fragment, stabilized with an added Pro-Gly-Pro sequence that confers CNS stability. Developed at the Institute of Molecular Genetics of the Russian Academy of Sciences and approved for clinical use in Russia and Ukraine, Semax is one of the most extensively studied and widely used nootropic/neuroprotective peptides from the Russian pharmacological tradition.
BDNF and Neurotrophic Signaling
Semax's most significant mechanistic property is its capacity to dramatically increase BDNF expression in the hippocampus and cortex — with studies showing increases of 7-fold or more in BDNF mRNA. This BDNF elevation is the central mechanism through which Semax exerts its neuroprotective and cognitive-enhancing effects, governing synaptic plasticity, neuron survival, neurogenesis, and cognitive function.
Stroke, Cognitive Enhancement, and ADHD Research
Semax's most established clinical application is neuroprotection and recovery enhancement in ischemic stroke — standard-of-care for ischemic stroke in Russia. Beyond neuroprotection, it has been studied for cognitive enhancement in healthy subjects (with documented improvements in attention, memory, and processing speed) and in ADHD, where its dopaminergic and noradrenergic modulating effects may address attention regulation deficits through a mechanistic pathway distinct from methylphenidate or amphetamine.
Quick Reference
| Literature-Reported Dose Range | 300-600mcg per administration |
| Literature-Reported Frequency | 1-2 times daily, preferably morning and early afternoon |
| Literature-Reported Cycle Length | 2-4 weeks continuous use maximum |
| Literature-Reported Washout | 1-2 weeks break between cycles to maintain effectiveness |
| Storage | Refrigerate at 2-8°C, do not freeze, protect from light |
| Timing | Morning for cognitive enhancement, avoid evening use due to potential alertness effects |
Research Indications
Cognitive
Memory Enhancement
Improved short-term and working memory performance in fatigued individuals and healthy subjects
Attention and Focus
Enhanced sustained attention during demanding cognitive tasks and prolonged work periods
Learning Acceleration
Faster acquisition of new information and improved retention in educational and training settings
Neuroprotective
Stroke Recovery
Accelerated restoration of brain functions and improved rehabilitation outcomes in ischemic stroke patients
Brain Trauma Support
Neuroprotective effects against various forms of brain injury and oxidative stress
Neurodegenerative Prevention
Potential protective effects against amyloid aggregation and age-related cognitive decline
Neuroplasticity
BDNF Upregulation
Rapid increase in brain-derived neurotrophic factor supporting neurogenesis and synaptic plasticity
Neural Connectivity
Enhanced default mode network activity and improved inter-brain region communication
Stress Resilience
Improved adaptation to chronic stress and enhanced cognitive flexibility under pressure
Research Protocols
As reported in cited literature and research-community logs (see Research Citations below) — not a personal dosing recommendation.
| Research Application | Dose | Frequency | Route |
|---|
| Cognitive enhancement (healthy adults) | 300-600mcg | 1-2 times daily | Nasal spray/drops |
| Learning and memory support | 600-900mcg | 2-3 times daily during study periods | Nasal spray/drops |
| Recovery from brain injury | 900-1500mcg | 2-3 times daily | Nasal drops (clinical supervision) |
| Anti-fatigue cognitive support | 400-800mcg | Single morning dose | Nasal spray |
Timing
Morning for cognitive enhancement, avoid evening use due to potential alertness effects. Typical onset: onset 15-30 minutes, peak 1-2 hours, duration 4-6 hours.
Peptide Interactions
These compounds address different research mechanisms represented in this preset. This is mechanistic complementarity, not evidence of clinical synergy: controlled studies of the exact combination are limited or unavailable, so interpret each exposure and safety signal independently.
These compounds address different research mechanisms represented in this preset. This is mechanistic complementarity, not evidence of clinical synergy: controlled studies of the exact combination are limited or unavailable, so interpret each exposure and safety signal independently.
Enhanced version of same peptide - do NOT use simultaneously. Choose one or the other based on desired duration and potency
Complementary anxiolytic effects while Semax provides cognitive enhancement
No known negative interactions, both support neuroplasticity through different mechanisms
May enhance effects of stimulants - monitor carefully and reduce stimulant doses when combining
Theoretical risk due to monoamine system effects - consult healthcare provider before combining
Reported Research Timeline
01Days 1–3 (reported in cited studies): initial cognitive clarity and focus enhancement, possible mild nasal sensation
02Week 1 (reported in cited studies): improved attention span and mental stamina during demanding tasks
03Week 2–3 (reported in cited studies): enhanced memory consolidation and learning capacity, stable mood effects
04Week 4 (reported in cited studies): peak cognitive benefits with improved stress resilience and mental flexibility
05Post-cycle: Gradual return to baseline over 3-7 days, some benefits may persist
Safety Notes
Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.
Start with lowest effective dose (300mcg) to assess individual response
Avoid concurrent use with other intranasal medications that cause vasoconstriction
Monitor for any signs of nasal irritation, bleeding, or persistent discomfort
Do not exceed 4-week continuous use periods without medical supervision
Potential to enhance effects of stimulants - reduce other stimulant doses accordingly
Seek Medical Attention If:
Severe nasal irritation, bleeding, or persistent congestion
Unusual anxiety, agitation, or sleep disturbances
Headaches that worsen with continued use
Any signs of allergic reaction (rash, difficulty breathing)
Significant blood pressure changes or heart palpitations
Quality Indicators
Verified Marker
Clear, colorless solution
Semax nasal solution should be transparent without particles or cloudiness
Verified Marker
Proper concentration labeling
Clearly marked as 0.1% or 1% Semax with accurate mcg per spray information
Verified Marker
Cold chain shipping
Nasal formulations should arrive with cold packs and require immediate refrigeration
Verified Marker
Sterile packaging
Sealed nasal spray bottles or ampoules with sterility assurance
Acceptable Range
Nasal irritation potential
Some mild nasal discomfort possible - discontinue if severe irritation occurs
Quality Concern
Crystallization or precipitation
Any visible crystals or particles indicate degradation or contamination
Research Citations
- Stroke Recovery Clinical Trial (2018)
Human | 110 patients | Semax + conventional therapy | Ischemic stroke recovery - fMRI Default Mode Network Study (2018)
Human | 24 participants | Single dose intranasal | Brain imaging analysis - Neuroprotective Effects in Brain Ischemia (2014)
Animal | Rat focal ischemia model | Gene expression analysis | 3-24 hours post-treatment - Cognitive Enhancement in Fatigued Workers (1996)
Human | 250-1000μg intranasal | Single dose | 24-hour observation - Functional Connectomic Approach to Studying Selank and Semax Effects
Panikratova YR, Lebedeva IS, Sokolov OY, 2020, Dokl Biol Sci - The Potential of the Peptide Drug Semax and Its Derivative for Correcting Pathological Impairments in the Animal Model of Alzheimer's Disease
Radchenko AI, Kuzubova EV, Apostol AA, 2025, Acta Naturae - The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia: genome-wide transcriptional analysis
Medvedeva EV, Dmitrieva VG, Povarova OV, 2014, BMC Genomics - Brain Protein Expression Profile Confirms the Protective Effect of the ACTH((4-7))PGP Peptide (Semax) in a Rat Model of Cerebral Ischemia-Reperfusion
Sudarkina OY, Filippenkov IB, Stavchansky VV, 2021, Int J Mol Sci - ACTH-like Peptides Compensate Rat Brain Gene Expression Profile Disrupted by Ischemia a Day After Experimental Stroke
Filippenkov IB, Shpetko YY, Stavchansky VV, 2024, Biomedicines
Research Focus
Neuroprotection, Cognitive enhancement, BDNF, Stroke recovery, ADHD research, Anxiety
Verified Vendors Carrying Semax
Frequently Asked Questions
What should researchers watch for with Semax?
Included for harm-reduction awareness only, in the event this compound is encountered outside its labeled research use. Inclusion here does not imply RUO Codes endorses, recommends, or instructs human use.
What should researchers expect over time with Semax?
Days 1–3 (reported in cited studies): initial cognitive clarity and focus enhancement, possible mild nasal sensation
How is Semax typically administered in research?
As reported in cited literature and research-community logs (see Research Citations below) — not a personal dosing recommendation.
Browse all peptides in the Encyclopedia →