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Semax

aka ACTH(4-7)PGP, Semax 0.1%, Semax 1%, N-Acetyl Semax, NA-Semax, N-Acetyl Semax Amidate, NA-Semax-A, NASA

NootropicCognitiveBdnfStrokeNeuroprotectionFocus

Last reviewed April 27, 2026 by Doserr editorial team · 17 references on this page

Information on this page is sourced from published research and is for educational purposes only. It does not constitute medical advice.

TL;DR

  • What it is: A synthetic seven-amino-acid ACTH(4-7) analog developed in Russia for neuroprotection and cognitive support.
  • What it's used for: Used as a nootropic for cognitive activation and in Russian clinical protocols for acute ischemic stroke.
  • Evidence level:limitedLimited -- human data are from Russian-only, non-replicated trials.

Dose at a glance

BeginnerCommonHigher end
Per dose200-300 mcg intranasal300-600 mcg intranasal100-200 mcg intranasal (N-Acetyl Semax Amidate / NASA variant)
Daily total200-300 mcg300-600 mcg (single morning dose) or up to 1,200 mcg split100-200 mcg
Schedule1-2x daily (5 days on / 2 off)1-2x daily (5 days on / 2 off)Once daily (5 days on / 2 off)
Cycle length1-2 weeks, 5 days on / 2 days off2-4 weeks, 5 days on / 2 days off1-4 weeks, lower per-dose reflects NASA community dosing convention

Synthesized from community-reported ranges. Not a recommendation. Route varies by compound — see Common route in What people report below.

Half-life
Short, Semax undergoes rapid enzymatic degradation primarily into Pro-Gly-Pro (PGP) fragments within approximately 1 hour of intranasal application in rats. No peer-reviewed human pharmacokinetic study has been published for any route.
Typical dose range
Doses below are from published research, not recommendations. Animal mechanistic studies: 50-250 mcg/kg intranasal or 100 mcg/kg IP (PMID: 17353092, 16635254). Russian human stroke trials: 12-18 mg/day intranasal for 5-10 days (PMID: 11517472). Optic nerve clinical study: dose not specified in available English-language abstract (PMID: 10741256). fMRI healthy volunteer study: intranasal 1% Semax solution (PMID: 30225715).
Route
Intranasal (nasal drops) in clinical studies and most animal studies, intraperitoneal (IP) in some rat mechanistic studies.
Evidence tier
limited

Animal or in-vitro studies only — no published human efficacy data.

What the research shows

Each topic links to the studies behind it. Click a topic to expand.

What we don't know yet

  1. Western clinical replication is absent, all human stroke efficacy data are from Russian-language publications with a non-randomized historical control design (PMID: 11517472)
  2. No published human pharmacokinetic data exist for any route, degradation half-life data are from rats only
  3. N-Acetyl Semax and N-Acetyl Semax Amidate are chemically distinct from Semax (differing at the N-terminus and C-terminus respectively), no comparative human PK or efficacy data exist
  4. Cognitive effects in healthy adults are not established by controlled trials, the only human neuroimaging study enrolled 24 volunteers and measured default mode network volume, not task performance (PMID: 30225715)
  5. Long-term safety data are absent, human exposure data cover only 5-10 day courses (PMID: 11517472), chronic effects on neurotrophin regulation, dopaminergic systems, and tolerance development are not published
  6. Gray-market quality control: compounded and research-grade preparations outside Russia have not been independently validated for purity, concentration, or stability in published studies

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