Semax Dosage Guide
Evidence-based protocols for the nootropic neuropeptide — intranasal and subcutaneous dosing, BDNF/NGF upregulation, N-Acetyl variants, cognitive enhancement stacks, cycling, and safety.
In This Guide
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Semax
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What Is Semax?
Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide analog of the adrenocorticotropic hormone (ACTH) fragment 4–10, developed at the Institute of Molecular Genetics of the Russian Academy of Sciences. It is one of the most thoroughly studied nootropic peptides in existence, with a clinical history spanning over three decades in Russian medicine. Semax is approved in Russia and Ukraine as a prescription medication for stroke recovery, cognitive enhancement, optic nerve atrophy, and peptic ulcer disease.
Unlike traditional stimulants that deplete neurotransmitters, Semax works by upregulating the expression of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) — two critical neurotrophins that support neuronal growth, synaptic plasticity, and long-term memory consolidation. It also modulates dopaminergic and serotonergic systems, enhances attention and working memory, and demonstrates potent neuroprotective properties against oxidative stress and ischemic damage.
A key characteristic of Semax is its paradoxically short plasma half-life (∼2–3 minutes) combined with long-lasting neurotrophin effects. While the peptide itself is rapidly degraded by aminopeptidases, the downstream BDNF and NGF upregulation persists for 24 hours or longer after a single administration. This means the dosing schedule is based on neurotrophin dynamics, not on maintaining plasma levels of the peptide itself.
Use our Peptide Dosage to calculate your exact dose based on vial size and concentration.
Key Characteristics:
- Nootropic neuropeptide — ACTH(4–10) analog with potent cognitive-enhancing, neuroprotective, and neurorestorative properties
- Heptapeptide — 7 amino acids: Met-Glu-His-Phe-Pro-Gly-Pro
- BDNF/NGF upregulation — increases expression of brain-derived neurotrophic factor and nerve growth factor in the hippocampus and cortex within hours of administration
- Dopaminergic modulation — enhances dopamine and serotonin signaling, supporting focus, motivation, and mood without depletion
- Ultra-short half-life, long-lasting effects — plasma half-life of ~2–3 minutes, but neurotrophin upregulation persists 24+ hours
- Primary route: intranasal — absorbed through nasal mucosa with partial blood-brain barrier bypass; subcutaneous injection is an alternative
For a complete overview of its mechanism and research, see our full Semax profile. New to peptides? Start with the Beginner's Guide to Peptides.
How Semax Dosage Is Determined
Semax dosing is supported by a substantial body of Russian clinical research spanning three decades. It is one of the few research peptides with an established pharmaceutical dosing framework, as it has been prescribed in Russia since the early 1990s. The standard 0.1% nasal solution (delivering approximately 50 mcg per drop) and 1% solution (delivering approximately 500 mcg per drop) are manufactured pharmaceutical products in Russia.
Russian Clinical Dosing Framework
In Russian clinical practice, Semax is prescribed at doses ranging from 200 mcg to several milligrams per day depending on the indication. Cognitive enhancement protocols typically use the 0.1% solution (lower doses), while stroke recovery and optic nerve treatment protocols use the 1% solution (higher doses). The clinical dosing has been refined through multiple controlled studies and decades of post-marketing experience.
Neurotrophin Upregulation Studies
Glazova et al. and other groups at the Russian Academy of Sciences demonstrated dose-dependent increases in BDNF mRNA expression following intranasal Semax administration. Peak BDNF upregulation occurs 3–8 hours post-administration and remains elevated for 24 hours. This long-lasting neurotrophin response — despite the peptide's 2–3 minute plasma half-life — is the pharmacological basis for once to three-times daily dosing rather than continuous infusion.
Melanocortin System Research
Semax's parent molecule (ACTH) acts through melanocortin receptors (MC1R–MC5R). The ACTH(4–10) fragment retains melanocortin activity that influences attention, learning, and memory without the adrenal steroidogenic effects of full-length ACTH. Ashmarin et al. characterized how this selective melanocortin activity translates to cognitive enhancement at the doses used clinically, establishing the dose range that maximizes nootropic benefit while avoiding overstimulation.
Variant Potency Comparisons
The development of N-Acetyl Semax and N-Acetyl Semax Amidate introduced more potent variants that required dose adjustment. Community experience and limited comparative data suggest NA-Semax is approximately 2–3 times more potent than standard Semax per microgram, while NASA (N-Acetyl Semax Amidate) may be 3–5 times more potent. These ratios are approximate and vary between individuals.
Standard Semax Dosage Ranges
Semax is primarily administered intranasally (nasal spray or drops) or by subcutaneous injection. Intranasal is the standard clinical route with the most supporting data. Dosages vary significantly depending on the variant (standard Semax vs. N-Acetyl variants) — always confirm which formulation you are using before dosing.
Standard Semax (MEHFPGP) — Intranasal
| Level | Dose per Administration | Frequency | Daily Total | Notes |
|---|---|---|---|---|
| Beginner | 200 mcg (100 mcg per nostril) | 1–2x daily | 200–400 mcg | Assess tolerance; ideal starting point for first-time users |
| Intermediate | 300–400 mcg | 2–3x daily | 600–1,200 mcg | Standard nootropic protocol; most common range for cognitive enhancement |
| Advanced / Clinical | 500–1,000 mcg | 2–3x daily | 1,000–3,000 mcg | Russian clinical dosing for stroke recovery, optic nerve repair; medical supervision recommended |
Standard Semax — Subcutaneous Injection
| Level | Dose per Injection | Frequency | Daily Total | Notes |
|---|---|---|---|---|
| Beginner | 100 mcg SubQ | 1x daily | 100 mcg | Conservative starting dose; assess individual response |
| Intermediate | 200 mcg SubQ | 1–2x daily | 200–400 mcg | Standard subcutaneous protocol for cognitive enhancement |
| Advanced | 300 mcg SubQ | 1–2x daily | 300–600 mcg | Higher-end dosing; monitor for overstimulation symptoms |
Administration Timing
- Morning administration is preferred: Semax enhances dopaminergic tone and alertness — take your first dose in the morning
- Second dose early afternoon: If dosing 2x daily, take the second dose before 2–3 PM to avoid sleep disruption
- Third dose (if applicable): No later than 4 PM. Avoid evening administration unless specifically needed for a cognitive task
- No fasting requirement: Unlike GH-releasing peptides, Semax does not require fasted administration. Food does not significantly impact absorption or efficacy
Semax Variants Comparison
Three variants of Semax are commonly available. They share the same core heptapeptide sequence but differ in chemical modifications that affect potency, bioavailability, and duration of action. Choosing the right variant — and adjusting dosage accordingly — is essential for safe and effective use.
| Parameter | Standard Semax | N-Acetyl Semax (NA-Semax) | N-Acetyl Semax Amidate (NASA) |
|---|---|---|---|
| Structure | MEHFPGP (unmodified) | Ac-MEHFPGP (N-terminal acetylation) | Ac-MEHFPGP-NH2 (acetylation + C-terminal amidation) |
| Relative Potency | 1x (baseline) | 2–3x | 3–5x |
| Typical Intranasal Dose | 200–600 mcg | 100–300 mcg | 50–200 mcg |
| Duration of Acute Effects | 4–6 hours | 5–8 hours | 6–10 hours |
| Enzymatic Stability | Low (rapid degradation) | Moderate (acetyl group protects N-terminus) | Highest (both termini protected) |
| Clinical Data | Extensive (decades of Russian clinical use) | Limited (community experience + preclinical) | Minimal (community experience primarily) |
| Stimulation Intensity | Mild to moderate | Moderate to strong | Strongest |
| Best For | First-time users, conservative dosing, clinical protocols | Experienced users, enhanced nootropic effect, convenience | Advanced users seeking maximum potency and duration |
Calculate Your Semax Dose
For subcutaneous injection, Semax is supplied as a lyophilized (freeze-dried) powder, typically in 5 mg or 10 mg vials. Reconstitute with bacteriostatic water and draw your dose using an insulin syringe. For intranasal use, many users reconstitute into nasal spray bottles with measured actuations.
Worked Example (Subcutaneous):
- Vial size: 5 mg (5,000 mcg) of Semax
- Bacteriostatic water added: 2.5 mL
- Concentration: 5,000 mcg ÷ 2.5 mL = 2,000 mcg per mL
- Target dose: 200 mcg
- Volume to draw: 200 ÷ 2,000 = 0.1 mL = 10 units on an insulin syringe
Quick Reference — 5 mg Vial (Subcutaneous)
| Bac Water Added | Concentration | 100 mcg Dose | 200 mcg Dose | 300 mcg Dose |
|---|---|---|---|---|
| 1 mL | 5,000 mcg/mL | 2 units (0.02 mL) | 4 units (0.04 mL) | 6 units (0.06 mL) |
| 2 mL | 2,500 mcg/mL | 4 units (0.04 mL) | 8 units (0.08 mL) | 12 units (0.12 mL) |
| 2.5 mL | 2,000 mcg/mL | 5 units (0.05 mL) | 10 units (0.1 mL) | 15 units (0.15 mL) |
| 5 mL | 1,000 mcg/mL | 10 units (0.1 mL) | 20 units (0.2 mL) | 30 units (0.3 mL) |
Intranasal Spray Preparation
For intranasal use, reconstitute the lyophilized Semax into a nasal spray bottle. Most metered nasal spray pumps deliver approximately 0.1 mL (100 microliters) per actuation. Adjust your reconstitution volume so that one spray delivers your target dose per nostril.
Nasal Spray Example:
- Vial size: 5 mg (5,000 mcg) of Semax
- Reconstitute with: 2.5 mL bacteriostatic water
- Concentration: 2,000 mcg per mL (or 200 mcg per 0.1 mL spray)
- One spray per nostril = 400 mcg total per administration
- This provides approximately 12–13 administrations per vial at 400 mcg per session
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Semax Dosage by Goal
Semax's broad mechanism of action — BDNF/NGF upregulation, dopaminergic modulation, and neuroprotection — makes it applicable to multiple cognitive and neurological goals. The optimal protocol varies depending on your primary objective.
Cognitive Enhancement & Focus
The most common use case. Semax enhances attention, working memory, mental clarity, and cognitive endurance. Particularly effective for demanding intellectual tasks, studying, or sustained focus sessions. The dopaminergic modulation provides motivation and drive without the crash associated with traditional stimulants.
- Dose (standard Semax): 200–600 mcg intranasally
- Frequency: 1–2x daily (morning + early afternoon)
- Cycle: 2–4 weeks on, 1–2 weeks off
- Onset: Acute focus effects within 15–30 minutes; full BDNF benefits develop over 2–4 weeks
Neuroprotection & Brain Health
For users seeking long-term neuroprotective benefits through sustained BDNF and NGF upregulation. This protocol prioritizes consistent neurotrophin elevation over acute cognitive effects. Supported by Russian clinical research on stroke recovery and cognitive decline in elderly patients.
- Dose (standard Semax): 300–600 mcg intranasally
- Frequency: 2–3x daily
- Cycle: 3–4 weeks on, 2 weeks off, repeat
- Note: Consistency is more important than high single doses for neurotrophin upregulation
Mood & Motivation Support
Semax's modulation of dopaminergic and serotonergic systems provides antidepressant-like effects in some users. It enhances motivation, emotional resilience, and a general sense of well-being without the emotional blunting sometimes associated with SSRIs. Often stacked with Selank for balanced mood support.
- Dose (standard Semax): 200–400 mcg intranasally
- Frequency: 1–2x daily (morning, or morning + early afternoon)
- Cycle: 2–4 weeks on, 1–2 weeks off
- Stack: Consider adding Selank (200–400 mcg intranasally) for synergistic mood and anxiety support
Stroke Recovery & Neuroregeneration (Clinical Protocol)
In Russian clinical practice, higher-dose Semax protocols are used for acute ischemic stroke recovery, traumatic brain injury, and optic nerve atrophy. These are medical protocols requiring professional supervision.
- Dose: 1% Semax solution, 600–3,000 mcg intranasally, divided across 2–3 daily administrations
- Duration: 10–14 days for acute stroke; extended courses for chronic conditions
- Medical supervision required: These doses are prescribed in clinical settings — do not self-administer high-dose Semax for neurological conditions without professional guidance
Attention & ADHD Support
Semax's dopaminergic modulation and attention-enhancing properties make it of interest for attention deficit. Russian research has explored its use in attention disorders in children, though most Western users apply it as an off-label nootropic. Moderate dosing provides sustained attention enhancement without the anxiety or cardiovascular effects of stimulant medications.
- Dose (standard Semax): 200–400 mcg intranasally
- Frequency: 1–2x daily (morning is critical; second dose before 2 PM)
- Cycle: 2–3 weeks on, 1–2 weeks off
- Note: If currently taking ADHD medication, consult a physician before adding Semax — dopaminergic interactions are possible
Cycling & Duration
Semax has a more favorable tolerance profile than many nootropics — it does not cause dependency and does not deplete neurotransmitters. However, cycling is still recommended to maintain optimal receptor sensitivity, prevent tolerance to acute effects, and allow natural neurotrophin regulation to function independently.
Cycling Protocols
| Protocol | On-Cycle | Off-Cycle | Notes |
|---|---|---|---|
| Conservative | 2 weeks | 1 week off | Best for first-time users; maintains strong acute effects |
| Standard | 3–4 weeks | 1–2 weeks off | Most common protocol; balances BDNF buildup with receptor reset |
| Extended | 4–6 weeks | 2–3 weeks off | For neuroprotection goals; allows maximum neurotrophin accumulation |
| Russian Clinical | 10–14 days | Varies by indication | Standard acute course in Russian medicine; may repeat after 1–3 month break |
Why Cycling Matters for Semax
Although Semax does not cause physical dependency or withdrawal, there are good reasons to cycle:
- Melanocortin receptor sensitivity: Prolonged continuous stimulation of melanocortin pathways can lead to reduced receptor sensitivity. Off-periods allow receptor density and sensitivity to normalize.
- Neurotrophin homeostasis: Chronic exogenous BDNF upregulation may shift the brain's baseline neurotrophin regulation. Periodic breaks allow natural BDNF/NGF regulation to function independently, which may improve long-term outcomes.
- Acute effect maintenance: The immediate nootropic effects (focus, clarity, motivation) tend to become less pronounced with continuous daily use. Cycling restores the full acute response.
- Hair health: The rare hair thinning reported with higher-dose Semax is more likely with prolonged continuous use. Cycling significantly reduces this risk.
Semax Stacking Protocols
Semax stacks well with several other peptides and nootropics due to its complementary mechanism of action. The fundamental stacking principle for Semax is to combine it with compounds that target different neurotransmitter systems or provide complementary neuroprotective pathways — not to stack multiple dopaminergic stimulants.
Semax + Selank — The Gold Standard Nootropic Stack
The most popular and well-regarded Semax stack. Semax enhances dopaminergic and noradrenergic signaling (focus, motivation, cognitive drive), while Selank modulates GABAergic and serotonergic systems (anxiety reduction, emotional stability, calm focus). Together they provide comprehensive cognitive enhancement with balanced stimulation and anxiolysis.
Semax + BPC-157 (Neuroregeneration Stack)
Combines Semax's neurotrophin upregulation (BDNF, NGF) with BPC-157's neuroregenerative and growth factor signaling for comprehensive nervous system support. BPC-157 has demonstrated neuroprotective effects in animal models and promotes GH receptor expression in the brain. Together they provide multi-pathway support for neurological recovery.
Semax + Nootropic Compounds (Cognitive Optimization)
Semax pairs well with other nootropic compounds that work through different mechanisms. Racetams (e.g., piracetam, aniracetam) modulate AMPA receptors and acetylcholine signaling, complementing Semax's neurotrophin and monoamine effects. Alpha-GPC provides choline for acetylcholine synthesis, supporting the cholinergic system alongside Semax's dopaminergic modulation.
| Compound | Dose | Frequency | Purpose |
|---|---|---|---|
| Semax | 200–600 mcg intranasal | 1–2x daily | BDNF/NGF, dopaminergic drive, core nootropic effects |
| Alpha-GPC | 300–600 mg oral | 1x daily (morning) | Cholinergic support, acetylcholine precursor |
Comprehensive Neuropeptide Stack (Semax + Selank + BPC-157)
The most comprehensive neuropeptide stack for users seeking maximum cognitive enhancement, neuroprotection, and emotional balance. Each compound addresses a different axis: Semax for dopaminergic drive and BDNF, Selank for GABAergic calm and serotonin modulation, and BPC-157 for neuroregeneration and growth factor support.
Explore more combinations with our Peptide Stack Builder or browse the Top 10 Peptide Stacks guide.
Safety, Side Effects & Contraindications
Common Side Effects
Mild and generally dose-dependent:
- Nasal irritation or mild burning (intranasal route) — typically resolves with continued use or switching nostrils between doses
- Mild headache — usually in the first 1–3 days, resolves spontaneously
- Increased alertness that may disrupt sleep if taken too late in the day — avoid evening dosing
- Slight appetite changes — some users report mild appetite suppression
Less common (typically at higher doses):
- Hair thinning or increased shedding — reversible upon dose reduction or discontinuation; more common with N-Acetyl variants at high doses
- Overstimulation, anxiety, or irritability — usually indicates the dose is too high; reduce and reassess
- Dizziness — rare, typically only with very high doses or in sensitive individuals
- Emotional sensitivity — some users report heightened emotional responses during the first few days
Contraindications
- Pregnancy and breastfeeding — no safety data exists for Semax during pregnancy or nursing. Avoid entirely.
- Active seizure disorders — Semax modulates excitatory neurotransmitter systems. While it has shown anticonvulsant properties in some research, individuals with active epilepsy should avoid use without medical supervision.
- Bipolar disorder (manic phase) — dopaminergic enhancement may exacerbate manic episodes. Use with extreme caution and medical oversight in bipolar patients.
- Concurrent MAO inhibitor use — Semax's monoaminergic effects may interact with MAO inhibitors. Do not combine without medical supervision.
- Known hypersensitivity — if you experience allergic-type reactions (rash, significant nasal swelling, difficulty breathing), discontinue immediately.
When to Stop or Reduce Dose
- Persistent anxiety, irritability, or agitation — reduce dose by 50% or take a break
- Insomnia that does not resolve by adjusting administration timing — reduce dose or eliminate the afternoon dose
- Noticeable hair thinning — reduce dose or discontinue; the effect is reversible
- Headaches that persist beyond the first 3–5 days — reduce dose and ensure adequate hydration
- Any symptom that feels unusual or concerning — err on the side of caution and discontinue
Common Semax Dosing Mistakes
Avoid these common errors to get the most out of your Semax protocol:
Frequently Asked Questions
Key Takeaways
- Semax is a potent nootropic neuropeptide — an ACTH(4–10) analog that upregulates BDNF, NGF, and modulates dopaminergic/serotonergic systems
- Standard intranasal dose: 200–600 mcg, 1–3x daily — adjust for variants (NA-Semax uses 1/2–1/3 the dose; NASA uses 1/3–1/5)
- Ultra-short half-life, long-lasting effects — the peptide is cleared in minutes, but BDNF/NGF upregulation persists 24+ hours
- Three variants available: Standard Semax (most clinical data), N-Acetyl Semax (2–3x potency), N-Acetyl Semax Amidate (3–5x potency, longest acting)
- Gold standard stack: Semax + Selank for balanced cognitive enhancement with anxiolysis
- Cycle 2–4 weeks on, 1–2 weeks off — maintains receptor sensitivity and acute effect potency; no withdrawal on discontinuation
- Excellent safety profile — decades of clinical use in Russia; “practically zero toxicity” per Russian classification. Main concerns are mild nasal irritation and rare reversible hair thinning at high doses
- Dose in the morning and early afternoon — avoid evening administration due to dopaminergic stimulation and potential sleep disruption
- No fasting required — unlike GH-releasing peptides, Semax does not need to be administered on an empty stomach
- Approved in Russia and Ukraine — not FDA-approved. Classified as a research peptide in most Western countries. Verify local regulations.
This article is for educational and informational purposes only. See our Disclaimer.
References
- Glazova NY, et al. “Semax, an analogue of ACTH(4-10), regulates expression of immune response genes during ischemic brain injury in rats.” Mol Genet Genomics. 2015;290(6):2355-2367.
- Dolotov OV, et al. “Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus.” Brain Res. 2006;1117(1):54-60. PubMed
- Ashmarin IP, et al. “Nootropic and analgesic effects of Semax following different routes of administration.” Neurosci Behav Physiol. 2005;35(8):843-848.
- Eremin KO, et al. “Semax, an ACTH(4-10) analogue with nootropic properties, activates dopaminergic and serotoninergic brain systems in rodents.” Neurochem Res. 2005;30(12):1493-1500. PubMed
- Medvedeva EV, et al. “The peptide semax affects the expression of genes related to the immune and vascular systems in rat brain focal ischemia: genome-wide transcriptional analysis.” BMC Genomics. 2014;15:228. PubMed
- Gusev EI, Skvortsova VI. “Current approaches to the treatment of ischemic stroke.” Zh Nevrol Psikhiatr Im S S Korsakova. 2005;Suppl 12:3-8.
- Levitskaya NG, et al. “Structure-activity relationship of ACTH(4-10) and its analogs. Part I. Heptapeptide modifications.” Neurosci Behav Physiol. 2008;38(8):829-836.
- Iasnetsov VV, Voronina TA. “Comparative study of Semax and Selank effects on cognitive function and behavior in rats.” Eksp Klin Farmakol. 2009;72(5):10-14.
- Polunin GS, et al. “Evaluation of the efficacy of Semax 0.1% nasal drops in optic nerve disease.” Vestn Oftalmol. 2000;116(1):15-17. PubMed
- Grivennikov IA, et al. “Semax stimulates the expression of BDNF and NGF genes in human glial cells.” Bull Exp Biol Med. 2008;146(1):140-143.
Next Steps
Continue your research with these resources.
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