Semax
ACTH (4-10) analog — synthetic heptapeptide (nootropic)
Semax is a synthetic seven-amino-acid peptide derived from a fragment of ACTH (4-10), developed in Russia for stroke and cognitive disorders. It is not approved in the US or EU. Evidence comes from Russian clinical studies, mainly in stroke, and from animal studies; Western trials are lacking.
Quick reference
How Semax is dosed in practice
Semax is taken as a nasal spray, 200–600 mcg a day in total, either as one dose or split into a morning and an early-afternoon dose.
Courses last 10–14 days, then about 2 weeks off. Many start at 200 mcg a day and increase gradually.
Where the numbers come from: Russian clinical use and practitioner convention. Higher doses used in Russian hospitals for stroke are given under medical supervision and aren't covered here; this guide doesn't list more than 600 mcg per dose.
Work out the units to draw with the reconstitution calculator and how long a vial lasts with the vial duration calculator.
How Semax works
Semax is a synthetic analog of ACTH (4-10) — a fragment of adrenocorticotropic hormone, with a Pro-Gly-Pro tail added for stability. The 7-amino-acid sequence (Met-Glu-His-Phe-Pro-Gly-Pro) keeps the brain-related activity studied for ACTH (4-10) without ACTH's cortisol-raising hormone effect.
In animal studies, Semax increased BDNF (a brain growth factor) in the hippocampus, affected dopamine and serotonin systems, and reduced signs of brain inflammation after injury. These are animal findings.
Clinical use in Russia centers on acute ischemic stroke, where small studies reported better recovery. Western trials haven't confirmed this, and use for focus or concussion is off-label without trial support.
In the DoseCraft framework, Semax is filed under Inflammation (neuroinflammation) and ATP Shortage (BDNF/NGF pathways) — a framework placement, not a tested outcome.
Reconstitution math
- Remove the flip-off cap from the 5 mg vial.
- Draw 2.5 mL of bacteriostatic water into a sterile syringe.
- Inject slowly down the vial wall.
- Swirl gently. Transfer to a nasal spray bottle for intranasal use.
- Refrigerate. Stable approximately 30 days.
Dose math
5 mg vial + 2.5 mL bac water → 2,000 mcg/mL (2 mg/mL).
Nasal sprayers typically deliver 0.1 mL per spray:
- • 1 spray ≈ 200 mcg (depends on sprayer)
- • 1 spray in each nostril ≈ 400 mcg
- • Daily total: 1–3 sprays (200–600 mcg), as one dose or split AM / early PM
Synergy stack
Semax + Selank — daytime cognitive stack
Practitioners pair Semax (alertness, cognition) with Selank (calm, anxiety) for daytime use. A common pattern is Selank in the morning and Semax in the morning and early afternoon. The combination hasn't been tested in trials.
Selank dose
250–400 mcg intranasal, once or twice a day
Semax dose
200–600 mcg a day intranasal, split AM / early PM
Safety + side-effect profile
Russian clinical use reports Semax as well tolerated. Although it comes from ACTH, the fragment was chosen because it lacks ACTH's cortisol-raising hormone effect.
Not established: long-term safety; there are no Western safety data. Avoid with: pregnancy, breastfeeding, psychotic disorders (no data).
Interaction notes: commonly paired with Selank. Use caution with stimulants (ADHD medicines, modafinil) — overstimulation is possible. If you take an antidepressant, tell your prescriber and introduce Semax gradually.
- • Mild headache in the first days (uncommon)
- • Occasional nasal irritation
- • Vivid dreams during dosing periods
- • No sedation reported
Frequently asked
What is Semax?
Semax is a synthetic seven-amino-acid analog of ACTH (4-10), developed in Russia. It is registered as a medicine in Russia, where it is used mainly for stroke and some cognitive conditions, but it is not approved in the US or EU. Its brain effects (such as raising BDNF) come mostly from animal studies.
What is the typical Semax dose?
200–600 mcg a day as a nasal spray, as one dose or split into two, for 10–14 day courses followed by about 2 weeks off. This guide doesn't list more than 600 mcg per dose. Higher amounts used in Russian hospitals for stroke are given under medical supervision.
Semax vs Selank — when to use which?
Semax is used mainly for alertness and cognition; Selank mainly for anxiety and calm focus. Practitioners often pair them — Selank for calm, Semax for demanding cognitive work. Neither has Western trials.
Does Semax work for ADHD?
Not established. Practitioners report better focus, but there are no Western trials of Semax for ADHD. It isn't a substitute for prescribed ADHD treatment; talk to your prescriber before combining or switching.
Is Semax effective for post-concussion recovery?
Not established. The Russian clinical studies are mainly in stroke, and animal studies show effects on BDNF and brain inflammation after injury, but there are no solid trials in concussion.
Is Semax addictive?
No dependence or withdrawal has been reported, but long-term use hasn't been studied in Western trials.
Should I cycle Semax?
Courses of 10–14 days followed by about 2 weeks off are the common pattern. Longer continuous use hasn't been studied.
Are there safety concerns?
Reported effects are generally mild: headache in the first days, nasal irritation, vivid dreams. The ACTH fragment in Semax was chosen because it lacks ACTH's cortisol-raising effect. Long-term safety hasn't been studied.
Related compounds
Often researched, stacked, or compared with Semax.
Cited research
Effectiveness of semax in acute period of hemispheric ischemic stroke (a clinical and electrophysiological study). Zh Nevrol Psikhiatr Im S S Korsakova, 1997.
Semax, an analog of ACTH(4-10) with cognitive effects, regulates BDNF and trkB expression in the rat hippocampus. Brain Res, 2006.
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