Semax
/seh-MAX/aka Семакс, ACTH(4-10) analog, Met-Glu-His-Phe-Pro-Gly-Pro
A modified seven-amino-acid fragment of ACTH, given as nasal drops, that raises BDNF in rat brains and is approved in Russia for stroke and cognitive problems.
Semax: educational research discussion. Not medical advice. Not a protocol for you.Details
- Reported range
- 200–600 mcg/day nasal
- Frequency
- 1–3× daily (reported)
- Cycle length
- 10–30 day courses (reported)
- Half-life
- Minutes in plasma; poorly characterized
- Route
- Nasal drops
Reported figures describe what is published or discussed. None of them is a dose for you.
Mechanism
What it is proposed to do
Semax keeps the ACTH(4-7) stretch (Met-Glu-His-Phe) and adds Pro-Gly-Pro, which slows breakdown. ACTH fragments this short lack the hormone's adrenal-stimulating action. In rats, a single intranasal dose raised hippocampal BDNF and TrkB signaling, and after experimental stroke it shifted immune and vascular gene expression. Links to melanocortin receptors and to dopamine and serotonin systems are proposed from animal work. Human mechanism data are limited to plasma BDNF in a Russian stroke study.
- 01
Semax
Intranasal heptapeptide; rapidly degraded in blood per Russian label data
established - 02
BDNF · TrkB ↑
1.4-fold hippocampal BDNF rise after one dose in rats
proposed - 03
Melanocortin and monoamine effects
Receptor, dopamine and serotonin effects described in animals
proposed - 04
Neuroprotection, cognition
Rodent ischemia models; small Russian stroke studies
proposed
Half-life. Russian prescribing information describes 60–70% absorption through the nasal lining, entry into the brain, and rapid breakdown in blood. A precise human half-life is poorly characterized. Animal studies report effects lasting far longer than plasma levels.
Dosing & cycles
What is reported, and where it comes from
Numbers below are labeled FDA label, clinical trial range or commonly reported range. They describe the published and discussed landscape. They are not instructions and not a protocol for you.
Dosing studio
Every figure is labeled by where it comes from.
Scale view: Russian stroke studies (1% drops)
Probe at 12 mg: inside the reported band (6–18 mg). Drag it to read the scale. It does not pick a number for you.
Typical cycle, as a calendar
Russian stroke course
Two 10-day courses, 20 days apart
The schedule used in a 2018 Russian stroke-rehabilitation study: a 10-day course, a 20-day gap, then a second course. Hospital use alongside standard care, shown as a shape, not a plan.
Cycle patterns
Russian stroke course
The schedule used in a 2018 Russian stroke-rehabilitation study: a 10-day course, a 20-day gap, then a second course. Hospital use alongside standard care, shown as a shape, not a plan.
Stacks
What it gets combined with
Why people pair things, and what nobody has tested.
Semax + Selank
2 compounds- Why people combine these
- Both came out of the same Russian research circle and are pitched as a pair: semax for focus, selank for calm.
- Caution
- No trial has tested the combination. Semax's Russian label lists anxiety disorders as a contraindication, which sits oddly with pairing it with an anxiolytic.
- What is unknown
- No published human data on this combination: dosing, interactions and long-term effects are all unstudied.
Evidence
How much of this is known
Evidence grade
C
Thin human data
Human data thin (pilots, uncontrolled, or none completed). Strong animal data and a lot of anecdote.
How we gradeClinical use in Russia, but the human studies are small, mostly Russian-language and hard to assess. The animal literature is larger and comes largely from the developer's own institute.
Human trial status
The clinical record is Russian. A 1997 study added semax to standard care in 30 acute ischemic stroke patients and compared them with 80 conventionally treated controls. A 2018 study of 110 stroke patients reported higher plasma BDNF and better functional scores with semax. Small imaging pilots in healthy volunteers exist. There are no Western trials and no placebo-controlled RCTs we could verify.
Limitations
- Clinical studies are small and Russian-language; English readers mostly get abstracts.
- Much of the mechanism work comes from the developer's own institute, which limits independent replication.
- No trials in healthy people seeking cognitive enhancement beyond small imaging pilots.
- FDA staff opposed adding it to the 503A bulks list in 2026, citing insufficient safety, efficacy and characterization data.
Sources to read
- Dolotov OV et al. Semax regulates BDNF and trkB expression in the rat hippocampus (Brain Res 2006)
- Medvedeva EV et al. Semax and gene expression in rat brain focal ischemia (BMC Genomics 2014)
- Gusev EI et al. Semax in the acute period of hemispheric ischemic stroke (Zh Nevrol Psikhiatr 1997, in Russian)
- Gusev EI et al. Semax at different stages of ischemic stroke, plasma BDNF (Zh Nevrol Psikhiatr 2018, in Russian)
- Semax 1% nasal drops, Russian prescribing information (Vidal drug reference, in Russian)
- FDA Pharmacy Compounding Advisory Committee, July 23–24, 2026
Links open PubMed, DailyMed, FDA or trial-registry searches. We do not cite what we have not described accurately.
Safety
Side effects, cautions, status
Commonly reported effects
- Russian prescribing information lists mild nasal irritation with prolonged use as the main side effect.
- Russian labeling contraindicates it in anxiety disorders, acute psychosis and seizure history, which hints at a stimulating profile.
- English-language safety data are sparse, and long-term safety is unknown.
- Research-market sprays are not the Russian pharmaceutical. Identity, concentration and sterility are unverified.
Who should be extra cautious
- Anxiety disorders or acute psychosis. Contraindicated in Russian prescribing information.
- Seizure history. Contraindicated in Russian prescribing information.
- Pregnancy or breastfeeding. Contraindicated in Russian prescribing information; not studied.
- Tested athletes. Not named by WADA, but S0 status is unclear. Confirm with your federation.
- Gray-market product. Online semax, including modified versions, is not the Russian drug. Content and purity vary.
Legal & regulatory status
Approved in Russia, not by FDA or EMA. Russian prescribing information covers 0.1% nasal drops for cognitive and neurological indications and 1% drops for acute ischemic stroke. In the US, FDA removed it from Category 2 in April 2026, and an advisory committee voted 8–5 (1 abstention) in July 2026 to recommend it for the 503A bulks list. It is not yet legal to compound.
2026 compounding context. July 23–24, 2026: FDA's Pharmacy Compounding Advisory Committee voted 8–5 (1 abstention) to recommend semax, free base and acetate, for the 503A bulks list. It was nominated for cerebral ischemia, migraine and trigeminal neuralgia. FDA staff had recommended against. Legal compounding requires a final FDA rule.
WADA. Not named on the list. S0 covers substances with no approval by any governmental health authority, and semax is approved in Russia, so S0 coverage is unclear. It is derived from ACTH, which is prohibited under S2, though it lacks ACTH's adrenal action. Confirm with your federation.
Storage & handling, high level
The Russian product is nasal drops in 3 mL bottles, stored per its own label. Research-market versions vary, and storage advice online is not based on stability data for those products.
Reconstitution and injection technique are clinical skills. The reconstitution calculator does arithmetic only.
FAQ
Questions people ask about Semax
Is semax approved anywhere?
Can US pharmacies compound it now?
Does it raise BDNF in people?
How is it different from selank?
What about "N-acetyl semax amidate"?
The monthly Evidence Brief
Keep up with the evidence
One email a month: new trials, grade changes and FDA or WADA updates across the whole atlas, Semax included. You get the free guide right away.
Free guide · PDF
10 Peptide Claims, Fact-Checked
13 pages · sent to your inbox right away
Email only. Unsubscribe from any email in one click. We do not sell or rent your address. Nothing we send is medical advice. Privacy