Semax
WELL RESEARCHEDNootropic peptide | Synthetic ACTH(4-10) analog
Updated: August 2026.
Key points
- What it is: nootropic peptide derived from ACTH (4-10).
- Main use: cognition, memory, focus and neuroprotection.
- Typical dose: 100–600 mcg per day, intranasal route.
- Key result: influences BDNF and dopamine; used in Russia for decades.
- Common effects: mild; occasional nasal irritation.
- Comparison: vs Selank: Semax is more cognitive/stimulating; Selank more calming.
- Status: not FDA-approved.
Overview
What is Semax?
Semax is a synthetic heptapeptide derived from a fragment of adrenocorticotropic hormone (ACTH 4-10), developed in Russia and studied for its nootropic and neuroprotective effects. It increases BDNF and NGF levels in the brain. In Russia it is used in the treatment of stroke and cognitive disorders. It is not FDA-approved.
Key benefits
Improved memory, concentration and learning; neuroprotective effect; greater mental stress resistance; and possible mood improvement, with a good safety profile.
Mechanism of action
It increases BDNF and NGF expression and modulates the dopamine and serotonin systems. Its intranasal administration lets it reach the brain quickly.
Quick start guide
Dosing protocol
| Phase | Dose | Route | Frequency |
|---|---|---|---|
| Standard | 100–600 mcg | Intranasal | 1–2 times/day (in cycles) |
The specific dose must be assessed by a healthcare professional.
🧮 Calculate your exact syringe dose →Semax vs Selank
| Semax | Selank | |
|---|---|---|
| Main effect | Cognition and focus | Anxiolysis and calm |
| Mechanism | BDNF and dopamine | Tuftsin, GABA/serotonin |
| Route | Intranasal | Intranasal |
| FDA status | Not approved | Not approved |
⚠️ Who should NOT use it
- Pregnancy or breastfeeding.
- Always under the supervision of a healthcare professional.
What to expect
- Day 1-3: possible improvement in concentration and mental clarity.
- Week 1: greater focus and better working memory.
- Week 2-3: better stress resistance and a more stable mood.
- Week 4: consolidated cognitive benefits.
- Side effects: generally mild; possible nasal irritation.
Side effects & safety
- Generally well tolerated; the most common side effect is mild nasal irritation.
- It can be activating: avoid using it late in the day so it doesn't affect sleep.
- Long-term safety data outside Russia are limited: use with supervision.
- Not recommended during pregnancy or breastfeeding.
- Consult your doctor if you take psychiatric medication.
- Allergic reaction: rash, itching or swelling.
- Severe headache, anxiety or marked mood changes.
- Intense or persistent nasal irritation.
- If you are pregnant, breastfeeding or planning a pregnancy.
Frequently asked questions
What is Semax?
Semax is a heptapeptide derived from a fragment of ACTH (4-10), developed in Russia and studied for its nootropic and neuroprotective effects.
What is Semax researched for?
It is studied for memory, concentration, neuroprotection and mood.
How does Semax work?
It increases BDNF and NGF expression (neurotrophic factors) and modulates the dopamine and serotonin systems.
How long does Semax take to work?
Acute effects on concentration are described in 30-60 minutes and sustained cognitive benefits in 1-2 weeks.
What is the usual Semax dose?
Most commonly 200-600 µg per day. The schedule should be assessed by a professional.
How is Semax administered?
Intranasally, as a spray in each nostril.
How is Semax stored?
Refrigerated and protected from light. See the storage guide.
What are the side effects of Semax?
It is described as well tolerated; the most common is mild nasal irritation. It can be activating, so it is advisable to avoid it late in the day.
Which peptides is Semax combined with?
The most cited combination is Semax with Selank, aimed at cognition and anxiety control.
Is Semax approved?
It is not FDA-approved; in Russia it is used in the treatment of stroke and cognitive disorders.
What is the difference between Semax and Selank?
Semax is more nootropic (cognition), while Selank is more anxiolytic (anxiety).
Research areas
- Memory and learning
- Concentration and focus
- Neuroprotection
- Mood
- Mental stress resistance
Related peptides
- Selank — Anxiolytic peptide; classic combination with Semax.
- Epitalon — Pineal tetrapeptide related to sleep and longevity.
- MOTS-c — Mitochondrial peptide associated with energy and metabolism.
Related articles
Related topics
- Semax for focus
- Semax for memory
- Semax dose
- Semax vs Selank
- Semax nootropic
- Semax and mood
Summary
What it is: Nootropic heptapeptide derived from ACTH(4-10).
How it is researched: Intranasal, 200-600 µg per day.
Key features: Increases BDNF and NGF; cognition and neuroprotection. Not FDA-approved.
Related peptides: Selank, Epitalon and MOTS-c.