CalcMyPeptide
Cognitive & Nootropic

Semax

Semax is a militarized neuro-stimulatory heptapeptide derived from a fragment of Adrenocorticotropic Hormone (ACTH). Engineered to maintain operational clarity under severe hypoxia and extreme stress, it stands as one of the most rigorously validated nootropics globally. Administered intranasally for virtually instantaneous blood-brain barrier penetration, Semax aggressively sharpens focus, accelerates complex problem-solving velocity, and provides massive neuroprotection against stroke-induced oxidative damage.

Reviewed by CalcMyPeptide Editorial Team
Last updated: April 2026Evidence: Moderate3 peer-reviewed citations

Quick Stats

Half-Life~2-3 minutes (intranasal active metabolites persist)
Dose Range200-600 mcg/day (intranasal)
Frequency1-3× daily (intranasal)
Vial Sizes3 mg, 5 mg
BioavailabilityIntranasal ~100% CNS delivery
Year Developed1980s

Scientific Data

Molecular Formula
Pro-Gly-Pro-Gly-Pro-Ala (heptapeptide ACTH analog)
Molecular Weight
~599 Da
CAS Number
Developer
Institute of Molecular Genetics, Russian Academy of Sciences

Mechanism of Action

Semax is a synthetic heptapeptide analog of ACTH (adrenocorticotropic hormone), specifically the ACTH(4-10) fragment with additional stabilizing modifications. It has neuroprotective and cognitive-enhancing properties. Semax increases BDNF and NGF (Nerve Growth Factor) expression, modulates the serotonergic system, and provides neuroprotection against oxidative stress.

Like Selank, Semax is approved in Russia as a prescription medication — specifically for stroke recovery, cognitive disorders, and optic nerve diseases. It is primarily administered intranasally due to its very short systemic half-life (~2-3 minutes).

Source: PMID: 17430556

Background & History

Semax is a synthetic heptapeptide derived from the ACTH(4-7) fragment (Met-Glu-His-Phe), with Pro-Gly-Pro added for stability, developed at the Institute of Molecular Genetics (Moscow) in the 1980s. It is approved in Russia for stroke rehabilitation, TBI, and optic nerve disease, with clinical use spanning 30+ years. Its primary mechanism involves upregulation of BDNF and NGF — the most important neurotrophic proteins for synaptic plasticity, neuronal survival, and cognitive function — placing it uniquely in the landscape of genuine nootropics with clinical validation.

Research Use Cases

  • Stroke rehabilitation and post-TBI neurological recovery
  • ADHD-like symptoms: focus, attention, and executive function
  • Nootropic: memory formation and recall enhancement
  • Optic nerve disease treatment (Russian clinical use)
  • Depression adjunct via BDNF upregulation

Dosing Protocol

Typical Dose200-600 mcg/day (intranasal)
Frequency1-3× daily (intranasal)
Half-Life~2-3 minutes (rapid metabolism)
Common Vial Sizes3 mg, 5 mg

Dosing Protocols

Standard Protocol

Dose
200 - 600 mcg
Frequency
Daily intranasal (1-3 doses)
Note: Approved in Russia for stroke recovery and cognitive disorders. Higher doses (600-1200 mcg) used clinically.

Body-Weight Dosing Reference

Estimated doses extrapolated from the published research range of 200600 mcg/day (referenced to 70 kg / 154 lb). These are approximations — consult a qualified healthcare provider for personalised guidance.

WeightLowTargetHigh
120 lb(54 kg)154 mcg309 mcg463 mcg
140 lb(63 kg)180 mcg360 mcg540 mcg
160 lb(73 kg)209 mcg417 mcg626 mcg
180 lb(82 kg)234 mcg469 mcg703 mcg
200 lb(91 kg)260 mcg520 mcg780 mcg
220 lb(100 kg)286 mcg571 mcg857 mcg
250 lb(113 kg)323 mcg646 mcg969 mcg

💉 For exact syringe units based on your vial concentration, use the Semax Reconstitution Calculator →

Administration

Route
Intranasal spray
Timing
Morning and/or afternoon. Fasting not required.
Fasting Required?
No — food timing not critical

Expected Timeline

Minutes to hours
Improved focus and mental clarity. Neuroprotective signaling initiated.
Week 2-4
Sustained BDNF/NGF elevation. Cognitive improvements compound. Stroke recovery benefits in clinical use.

Who Is It For?

Neuroprotection / Stroke Recovery

High

Approved in Russia for stroke recovery. BDNF and NGF upregulation supports neuronal repair.

Cognitive Enhancement / Nootropic

High

Does not affect cortisol despite ACTH origin. Well-tolerated cognitive booster.

Reconstitution Example

Vial
5 mg
Water
5 mL
Concentration
1 mg/mL
Per Unit (100u syringe)
10 mcg
Dose of 200 mcg = 20 units on a 100-unit insulin syringe

Safety & Considerations

Approved in Russia for stroke recovery and cognitive disorders. Good clinical safety profile. Does not affect cortisol. Primary route is intranasal.

Regulatory & Legal Status

FDA Status (US)
Research Only

Approved in Russia as a nasal spray; not FDA-approved

WADA Status (2026)
Not Listed

Not currently on the WADA 2026 Prohibited List. Policies may change — verify before competition.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Interactions & Contraindications

Intranasal route required for adequate CNS bioavailability (nasal mucosa→olfactory neurons). ACTH-like structure may weakly affect cortisol — monitor with prolonged high-dose use. No significant drug interactions documented. Avoid in patients with active epilepsy (CNS stimulation theoretically could lower threshold).

Synergies & Common Stacks

Classic Russian nootropic stack: Semax enhances cognitive performance; Selank reduces performance anxiety. Together they support both cognitive output and emotional stability.

Semax provides the BDNF; Dihexa promotes the synaptogenesis to utilize it. Potentially powerful combination for neurological recovery or enhancement.

Semax vs. Selank

AttributeSemaxSelank
Primary EffectStimulating cognitive enhancerCalming anxiolytic
BDNF ImpactStrong BDNF upregulationMild BDNF impact
Mood EffectEnergising / drive / motivationAnti-anxiety / calm focus
TimingBest AM useBest PM or high-stress use
ApprovalRussia (Semax nasal spray)Russia (Selank nasal spray)

Verdict: Semax is the stimulating neuropeptide for cognitive performance and BDNF-driven neuroplasticity. Selank is the calming partner. Together they offer a full-spectrum nootropic from two directions.

Dosing Quick Reference

Semax— Dosing Guide
Dose Range
200-600 mcg/day (intranasal)
Half-Life
~2-3 minutes (rapid metabolism)
Frequency
1-3× daily (intranasal)
Route
Subcutaneous
3 mg vial5 mg vial
💧 5 mL BAC water📐 1 mg/mL concentration💉 10 mcg/unit (100u syringe)
Cognitive & Nootropiccalcmypeptide.com

Frequently Asked Questions

Does Semax affect cortisol like ACTH?
No — Semax is from ACTH(4-10), which does not contain the hormonal region (residues 1-3) responsible for cortisol stimulation. Confirmed no adrenal effect.
What is the Semax dosing protocol?
200-600 mcg daily via intranasal spray, 1-3 doses. Clinical settings use 600-1200 mcg for stroke recovery.

References

  1. Dolotov OV et al. "Neuroprotective effects of the synthetic ACTH analogue Semax".” Journal of Neurochemistry (2006). PMID: 16978359

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