In plain English
Semax is a short peptide built from a piece of ACTH, a natural hormone, with a small tail added to make it last longer. Taken as a nasal spray, it is used for focus, memory and mental energy. It has been prescribed in Russia for decades, mainly after strokes.
What it's used for
- Focus, concentration and mental energy
- Memory and learning
- Recovery after stroke or brain injury (its main medical use in Russia)
- Stress resilience and mood
Benefits
Most Semax research comes from Russian clinical and animal studies. These have shown:
- Better recovery of movement and thinking after stroke in clinical studies
- Higher levels of BDNF, a protein that supports learning and new brain connections, in animal studies
- Improved attention and memory under stress
- Protective effects on brain cells when oxygen supply is low
Users report sharper focus, clearer thinking and more mental stamina, often within an hour of a dose.
How it works
In simple terms: Semax appears to boost the brain’s own growth and repair signals.
It is based on ACTH (4-10), a fragment of a pituitary hormone that affects the brain without the hormone’s effects on the adrenal glands. Studies link Semax to increased BDNF and its receptor, changes in dopamine and serotonin activity, and protection of brain cells under stress. The Pro-Gly-Pro tail slows its breakdown.
Development history
- 1980s: Developed at the Institute of Molecular Genetics of the Russian Academy of Sciences.
- 1990s onward: Approved and prescribed in Russia and nearby countries as nasal drops, mainly for stroke and other brain conditions.
- 2010s–today: Becomes popular worldwide as a nootropic, along with longer-lasting versions such as N-Acetyl Semax Amidate.
Typical protocols
These ranges are what users commonly report.
| Route | Daily amount | How it is split | Length |
|---|---|---|---|
| Nasal spray | 200–600 mcg | 1–3 doses, usually morning and early afternoon | 2–4 weeks, then a break |
| Subcutaneous injection | 100–300 mcg | Once daily | 2–4 weeks |
Users usually avoid evening doses, since Semax can make it harder to fall asleep.
Cycling
Commonly used for 2–4 weeks followed by a break of similar length.
Administration options
- Nasal spray: the main route. Powder is mixed with bacteriostatic water or saline and transferred into a nasal spray bottle; each spray delivers a measured amount.
- Subcutaneous injection: used by some, at lower doses.
Reconstitution and dosing calculator
For a nasal spray, users divide the vial amount by the spray bottle volume to find the dose per spray (most nasal pumps deliver about 0.1 mL per spray). For injection, use the calculator below.
Draw your syringe to
– units
- Volume to draw
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- Concentration
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- Each unit holds
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- Doses per vial
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Show the math
This tool does arithmetic only. It does not choose a dose or confirm that any substance is right for you. Double-check every result against your syringe and your clinician’s instructions.
Side effects and safety
- Users report that Semax is generally well tolerated. Occasional effects include nasal irritation, headache, restlessness and trouble sleeping if taken late in the day.
- Some users notice irritability or anxiety at higher doses.
- Long-term effects outside Russian clinical use have not been well studied.
- Avoid during pregnancy and breastfeeding.
Common stacks
- Selank: the most common pairing, balancing Semax's stimulating effect with Selank's calming effect.
- Users report combining it with other nootropics such as Dihexa or with NAD+.
Storage
Powder: refrigerate, dry and away from light.
Mixed nasal spray or vial: refrigerate at 2–8 °C and use within about 2–4 weeks.
Compare with
- Selank: also from the same Russian institute, but calming rather than stimulating.
- N-Acetyl Semax Amidate: a modified Semax marketed as stronger and longer-lasting.
Frequently asked questions
How fast does Semax work?
Users commonly report effects within 30–60 minutes of a nasal dose.
How do I work out the dose per spray?
Divide the total peptide in the bottle by the liquid volume to get the concentration, then multiply by your pump’s spray volume (often 0.1 mL).
Can I take it at night?
Most users avoid it in the evening because it can interfere with sleep.
Semax or Selank?
Semax is used for focus and energy; Selank for calm and stress relief. Many people use both.
References
- 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.
- Gusev EI, et al. Effectiveness of Semax in acute period of hemispheric ischemic stroke. Zh Nevrol Psikhiatr Im S S Korsakova. 1997.