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Semax

Cognitive & nootropic

Also known as: ACTH (4-10) analog, Semax heptapeptide

A Russian nootropic peptide, used intranasally for focus, memory, and recovery from stroke.

Safety:Widely used in Russia but barely studied in Western trials. Usually taken as a nasal spray. Higher doses can feel stimulating and nudge up anxiety or blood pressure.

2.What it is / mechanism

Semax is a short peptide based on a fragment of ACTH, a natural hormone, but changed so it does not act like a stress hormone. In the brain it raises neurotrophic factors, especially BDNF and NGF, which help neurons grow and survive, and it nudges dopamine and serotonin signaling. It is a registered prescription medicine in Russia and Ukraine for ischemic stroke and cognitive problems. It is usually given as nose drops or spray, which sends it toward the brain while skipping the stomach.s1

3.What the evidence supports

  • Limited human dataSupports focus, memory, and recovery in cognitive and stroke conditions.s1

    Used clinically in Russia for decades, but the trials are mostly Russian and small, with little Western replication.

  • Animal data onlyRaises BDNF and NGF in the brain.s1

    Well replicated in animals, which is the mechanistic basis for most claims.

  • Anecdotal onlyBoosts focus and mood in healthy people.s1

    Popular nootropic use. One study noted stimulant like effects and slightly higher anxiety at a higher dose.

4.Dosing

Limited human data
Route(s)intranasal (most common), subcutaneous
Typical rangeIntranasal doses run about 50 to 500 mcg per day, as a 0.1 percent solution, depending on the goal.
FrequencyOnce or twice daily, in short courses
Cycle guidanceCourses often last 10 to 14 days, repeated as needed.
NotesMost people use it as nose drops or spray, not injection. The blood is short, but the BDNF effect it triggers lasts longer. For nasal use, what matters is the concentration in mcg per drop, not syringe units. Start low, since higher doses can feel stimulating.
s1

5.Reconstitution

Vial sizes5 mg, 10 mg
DiluentBacteriostatic or sterile water. Many people mix it for nasal use rather than injection.
ConcentrationExample: a 5 mg vial plus 5 mL of water gives 1 mg/mL. For nasal use, work out mcg per drop from that. For subcutaneous use, a 300 mcg dose is 0.3 mL, which is 30 units on a U-100 syringe.
NotesSold as a lyophilized powder or as a ready made nasal spray. Powder is commonly 5 mg or 10 mg per vial.

Reconstitution calculator

Pick your vial size and how much water you add to see the draw volume and syringe units for a dose. Open the full calculator →

Inputs

Reminder: 1 mg = 1,000 mcg

mg

Total amount stated on the vial, e.g. 5 mg.

mL

How much diluent you draw into the vial.

mcg

Target dose per injection, in mcg. 1 mg = 1,000 mcg.

Result

Draw to

10 units

= 0.1 mL on your syringe

Concentration
2,500 mcg/mL
Per unit
25 mcg / unit
Doses per vial
20

Educational estimate only. Not medical or dosing advice. Verify every calculation independently before use.

General reconstitution technique →

6.Storage & stability

Lyophilized (dry)

TempFreeze for long term storage, or 2 to 8 short term
Shelf lifeMany months when frozen
NotesKeep dry and out of light until you mix it.

Reconstituted

Temp2 to 8 (refrigerated)
Shelf lifeAbout 2 to 4 weeks
NotesDo not freeze after mixing. Discard if cloudy or discolored.

General storage & stability guide →

7.Reported side effects

  • CautionNasal irritation or post nasal drip(common)s1Mainly with the nasal spray.
  • CautionHeadache(uncommon)s1
  • CautionFeeling stimulated or slightly anxious at higher doses(uncommon)s1
  • CautionTemporary rise in blood pressure(uncommon)s1

8.Interactions & stacking risks

  • CautionStimulants

    Can add to the stimulant like effect at higher doses.

  • CautionSerotonergic medicines such as SSRIs

    It modulates serotonin, so use care alongside serotonergic drugs.

9.Contraindications / who should avoid

  • SeriousPregnancy or breastfeeding

    No safety data in pregnancy or breastfeeding.

  • WarningUncontrolled anxiety or high blood pressure

    Higher doses can raise anxiety and blood pressure.

10.COA & purity notes

Common adulterantsnasal sprays that vary in concentration, underdosed or mislabeled vials
MislabelingNasal products vary in strength, so check the concentration. A recent third party COA helps confirm identity and purity.
NotesRegistered as a medicine in Russia and Ukraine, but not approved in the US. Research and gray market material is unregulated.

How to read a COA →

11.Sources

  1. [s1]Peptide research review (2023). Semax: neuroprotective and nootropic actions and Russian clinical use (review). review

Last reviewed 2026-07-08 · status: reviewed