Dashnaiv Peptides
Compounds·neuropeptides nootropic·ACTH(4-7) analog; BDNF and monoaminergic effects reported

Semax: nasal spray doses in studies and in practice, side effects, how it works, and the Russian trials behind it

What 208 indexed publications and 1 randomized trials actually state about semax, sentence by sentence, each tied to its source and labeled by the kind of evidence it is.

Human clinical trial Reviewed 37 sources Updated Also: Met-Glu-His-Phe-Pro-Gly-Pro

At a glance

Evidence availability
Human clinical evidence
Strongest tier in the indexed literature
Indexed publications
208
Europe PMC, title or abstract, 2026-09-14
Human studies in ledger
7
1 randomized; study count, not efficacy proof
Approval
none found
no registered development programme
Routes reported
intranasal, intraperitoneal
from studies in this ledger
Studied in
Humans, Mice, Rats
24 primary studies in the evidence table
Reviewed by Adam Mirando, PharmD, on . What changed

What Semax is and how it acts

Semax is a peptide in the neuropeptides nootropic class (ACTH(4-7) analog; BDNF and monoaminergic effects reported). Europe PMC indexes 208 publications naming it or a listed alias in a title or abstract, including 1 randomized controlled trials and 3 clinical trials of any design, as of . The strongest evidence tier in that literature is human clinical trials.

This page reports what those studies state, sentence by sentence, with each statement tied to its source and labeled by the kind of evidence it is. It does not recommend use, and it does not translate study doses into anything personal.

What the evidence level means

Publication counts show what is indexed, not how strong the evidence is. The ledger below separates human clinical records from preclinical, analytical, and in-vitro work.

Human clinical studies in this ledger71 randomized · 6 other human clinical
Evidence strengthNot yet assessedSeparate from evidence availability
Efficacy signalNot yet assessedRead the study result, not the tier alone

Interpretation boundary: An indexed publication count is a discovery measure. It does not establish efficacy, safety, approval, or a personal treatment plan.

Semax in two minutes

What it is. A seven-amino-acid fragment of the hormone ACTH, stabilised with a three-amino-acid tail, developed in Russia and registered there as a nasal medicine (dates cited vary by formulation) for stroke recovery, optic nerve disease and cognitive impairment. Outside Russia it is unlicensed and sold as a research chemical.

What the research actually shows. 208 indexed publications, one randomized trial and several small Russian clinical studies in stroke patients, optic nerve disease and psoriasis, plus animal work on BDNF and neuroprotection. Most of the trial literature is in Russian and not indexed here. No English-language placebo-controlled trial in healthy adults exists for the cognitive uses it circulates for.

What people commonly report using. 200 to 600 micrograms a day intranasally, in short courses; a vendor variant, N-acetyl Semax amidate, at similar doses. The Russian label doses for stroke are far higher, around 6 milligrams a day of the 1 percent solution.

Status. A registered medicine in Russia; unapproved everywhere else; not named on the WADA list.

Where the evidence is thinnest. Any controlled trial in healthy adults; any English-language safety data; anything at all on the acetylated amidate variant.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

How Semax is thought to work

Written from general pharmacology and the development record, and marked as editorial synthesis; the measurements behind it are quoted in the biomarker section.

  • Semax is a seven-amino-acid peptide, Met-Glu-His-Phe-Pro-Gly-Pro: the fragment of the pituitary hormone ACTH covering positions 4 to 7, extended with a Pro-Gly-Pro tail that slows its breakdown. It was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences in the 1980s and 1990s and is registered as a medicine in Russia as intranasal drops or spray at 0.1 and 1 percent; sources give registration dates from the 1990s to 2011 depending on formulation and indication.Editorial synthesis
    Editorial synthesis from general knowledge
  • Despite coming from ACTH, it has no meaningful effect on the adrenal glands or cortisol at the doses studied: the fragment retains the part of the hormone associated with attention and memory effects in animals and loses the part that drives steroid release. The mechanisms proposed in Russian animal work are increased expression of brain-derived neurotrophic factor (BDNF) and its receptor TrkB in the hippocampus, modulation of dopamine and serotonin signalling, and a broad shift in gene expression toward neuroprotection after ischaemia. In the one indexed human mechanistic study, stroke patients given Semax showed raised plasma BDNF.Editorial synthesis
    Editorial synthesis from general knowledge
  • Almost all of the evidence is Russian, much of it published in Russian-language journals that Europe PMC indexes only by English abstract or not at all. That is why a compound with a national marketing authorisation shows 208 indexed publications, one randomized trial and no regulatory record in ChEMBL. The evidence is not absent; it is largely outside the indexes this site draws on, and it has not been replicated by groups outside Russia.Editorial synthesis
    Editorial synthesis from general knowledge

What happened in the human studies?

This record's ledger holds 7 primary human studies, of which 4 are trials. Few enough to show in full: each card quotes what its abstract reported about Semax. Read them before any other section on this page.

  • Clinical trial humans n = 43 2018 Human clinical trial
    Administration of semax, regardless of the timing of rehabilitation, increased BDNF plasma levels which remained high during the whole study period.
    Source pmid-29798983 · quoted verbatim from the abstract
  • Randomized controlled trial humans n = 27 2007 Human clinical trial
    However, 1% semax significantly improves the total estimate of life quality due to the improvement of emotional state and motivation in MND patients with the maximal effect on day 10.
    Source pmid-18379501 · quoted verbatim from the abstract
  • Controlled clinical trial humans 2000 Human clinical trial
    Addition of semax to therapeutic complex in patients with diseases of the optic nerve had a favorable impact on the intensity and rate of recovery and improved the visual functions.
    Source pmid-10741256 · quoted verbatim from the abstract
  • Controlled clinical trial humans n = 30 1997 Human clinical trial
    It was established that including of Semax in combined intensive therapy of acute ischemic stroke had some influence on the rate of restoration of the damaged neurological functions in terms of increasing the regress of general cerebral and focal, especially motor disorders.
    Source pmid-11517472 · quoted verbatim from the abstract
  • Human study humans 2020 Observational, human
    The present study was aimed at the assessment of effects of anxiolytic Selank and nootropic Semax on the whole-brain resting-state functional connectivity (FC) of each of the predefined regions of interest (ROIs) in 52 healthy participants.
    Source pmid-32342318 · quoted verbatim from the abstract
  • Human study humans n = 58 2015 Observational, human
    It was found that the inclusion of semax in complex treatment of patients with psoriasis complicated by metabolic syndrome led to a decrease in the initially elevated serum levels of total cholesterol, triglycerides, LDL cholesterol and to an increase in the initially reduced levels of HDL cholesterol, in contrast to the standard treatment, which did not produce any statistically significant effect on the levels of total cholesterol, triglycerides, LDL cholesterol, and HDL cholesterol in the blood serum.
    Source pmid-27051926 · quoted verbatim from the abstract
  • Human study humans 2005 Observational, human
    Semax treatment resulted in significant clinical improvement, stabilization of the disease progress and reduced a risk of stroke and transitory ischemic attacks in the disease course.
    Source pmid-15792140 · quoted verbatim from the abstract

What the evidence shows

One row per primary study in this record's ledger. Fields are read from each paper's indexing and abstract. "Analytical method" marks papers about detecting or measuring the compound rather than about its effects.

24 primary studies in this record's ledger, strongest evidence first. A dash means the abstract did not state the value.
StudyDesignnSpeciesDoseRouteDurationReported outcomeTier
Gusev 2018 Clinical trial 43 Humans6000 mcg/day—— Administration of semax, regardless of the timing of rehabilitation, increased BDNF plasma levels which remained high during the whole study period. Human clinical trial
Serdiuk 2007 Randomized controlled trial 27 Humans——10 day; 2 weeks However, 1% semax significantly improves the total estimate of life quality due to the improvement of emotional state and motivation in MND patients with the maximal effect on day 10. Human clinical trial
Polunin 2000 Controlled clinical trial — Humans——— Addition of semax to therapeutic complex in patients with diseases of the optic nerve had a favorable impact on the intensity and rate of recovery and improved the visual functions. Human clinical trial
Gusev 1997 Controlled clinical trial 30 Humans——10 days It was established that including of Semax in combined intensive therapy of acute ischemic stroke had some influence on the rate of restoration of the damaged neurological functions in terms of increasing the regress… Human clinical trial
Panikratova 2020 Human study — Humans——— — Observational, human
Dontsova 2015 Human study 58 Humans600 mg/dayintranasal10 days It was found that the inclusion of semax in complex treatment of patients with psoriasis complicated by metabolic syndrome led to a decrease in the initially elevated serum levels of total cholesterol, triglycerides,… Observational, human
Gusev 2005 Human study — Humans——— Semax treatment resulted in significant clinical improvement, stabilization of the disease progress and reduced a risk of stroke and transitory ischemic attacks in the disease course. Observational, human
Radchenko 2025 Animal study — Mice——— The open field, novel object recognition, and Barnes maze tests demonstrated that both Semax and its derivative improved cognitive functions in mice. Animal, preclinical
Liu 2025 Animal study 6 Rats, Mice——— Key results Semax improved SCI functional recovery and inhibited LMP-related pyroptosis in SCI mice and neuroinflammation models, by decreasing oxidative stress. Animal, preclinical
Filippenkov 2025 Animal study — Rats——— These DEGs were associated with inflammation, predominantly. Animal, preclinical
Filippenkov 2024 Animal study — Rats——— — Animal, preclinical
Inozemtseva 2024 Animal study — Rats—intraperitoneal— We found that chronic treatment with Semax and MTII reversed or substantially attenuated CUS-induced anhedonia, BW gain suppression, adrenal hypertrophy and a decrease in the hippocampal levels of BDNF. Animal, preclinical
Filippenkov 2024 Animal study — Rats—intraperitoneal— Both peptides predominantly caused decrease in expression of the genes associated with the immune system. Animal, preclinical
Filippenkov 2023 Animal study — Rats——— — Animal, preclinical
Stavchansky 2022 Animal study — Rats——— Moreover, there were IC genes ( iL1b , iL6 , and Socs3 ) for PGP, as well as IC ( iL6 , Ccl3 , Socs3 , and Fos ) and NC genes ( Cplx2 , Neurod6 , and Ptk2b ) for PGPL, that significantly changed in expression levels… Animal, preclinical
Filippenkov 2021 Animal study — Rats——— Furthermore, both peptides upregulated the expression levels of many genes that displayed decreased expression after ARS, and vice versa, the MC peptides downregulated the expression levels of genes that were… Animal, preclinical
Kolacheva 2021 Animal study — Mice——— However, SEMAX, slightly but reliably, increased striatal dopamine when administered before MPTP treatment, which indicates that it is more effective as an inductor of endogenous neurotrophic factor secretion rather… Animal, preclinical
Sudarkina 2021 Animal study — Rats——— — Animal, preclinical
Shakova 2021 Animal study — Rats25 μg/kgintranasal, intraperitoneal7 days; 21 days Administration of Mexidol or Semax was associated with preservation of the neuron number and neuronal expression of PGC-1α, stimulation of the nuclear translocation of PGC-1α, and increased contents of protein markers… Animal, preclinical
Svishcheva 2021 Animal study — Rats—intraperitoneal— Administration of the peptide led to a decrease in corticosterone concentration, alleviated stress-induced pathomorphological changes, and promoted adaptation of the intestinal wall to stress. Animal, preclinical
Glazova 2021 Animal study — Rats——40 weeks Semax administration reduced the anxiety-like behaviour, improved learning abilities and normalized the levels of brain biogenic amines impaired by the FA exposure. Animal, preclinical
Filippenkov 2020 Animal study — Rats——— — Animal, preclinical
Elagina 2020 Animal study — Rats200 μg/kg—— Deltalicin in a dose 100 μg/kg and Semax in a dose 200 μg/kg as well as sulodexide corrected lipid metabolism disorders: the content of total cholesterol, triglycerides, LDL, index of atherogenicity decreased and HDL… Animal, preclinical
Medvedeva 2014 Animal study — Rats——— Three hours after pMCAO, Semax influenced the expression of some genes that affect the activity of immune cells, and, 24 h after pMCAO, the action of Semax on the immune response increased considerably. Animal, preclinical

What doses did studies use?

These are doses from Russian clinical studies of stroke and other indications, and from rats. No trial has tested a Semax dose for cognition in healthy adults; the 200 to 600 microgram figures that circulate follow the Russian 0.1 percent label loosely. Each entry is a sentence quoted from the study's abstract, with the study's design, sample size and year in front of it. Comparator doses in the same sentence are not attributed to semax.

  • Clinical trial humans n = 43 2018 Human clinical trial
    Doses stated in the abstract: 6000 mcg/day
    Standard regimen of semax included 2 courses (6000 mcg/day) for 10 days with 20 day interval.
    Source pmid-29798983 · quoted verbatim from the abstract, emphasis added
  • Human study humans n = 58 2015 Observational, human
    Doses stated in the abstract: 600 mg/day
    In group 1, 58 patients received conventional therapy, while 60 patients in group 2 received the same with additional 0.1% semax solution intranasally 600 mg/day for 10 days.
    Source pmid-27051926 · quoted verbatim from the abstract, emphasis added
  • Animal study rats 2021 Animal, preclinical
    Doses stated in the abstract: 25 μg/kg
    Mexidol (100 mg/kg) was administered intraperitoneally, and Semax (25 μg/kg) was administered intranasally, for 7 days each.
    Source pmid-33806692 · quoted verbatim from the abstract, emphasis added
  • Animal study rats 2020 Animal, preclinical
    Doses stated in the abstract: 200 μg/kg
    Deltalicin in a dose 100 μg/kg and Semax in a dose 200 μg/kg as well as sulodexide corrected lipid metabolism disorders: the content of total cholesterol, triglycerides, LDL, index of atherogenicity decreased and HDL concentration increased.
    Source pmid-32246363 · quoted verbatim from the abstract, emphasis added

Semax dosage chart: the Russian label, the studies, and what circulates

Three different sources of figures that are routinely blended together online. The concentration of the solution changes the dose tenfold.

Source of the figureDoseScheduleNote
Russian label, 0.1% solution (cognitive, paediatric attention, optic nerve)About 200 to 600 µg/day: 2 to 3 drops per nostril, 2 to 3 times dailyCourses of 10 to 14 daysEach drop of 0.1% delivers about 50 µg
Russian label, 1% solution (acute stroke)6 to 18 mg/day intranasallyUp to 10 daysTen times the concentration; hospital use
Indexed clinical study (Gusev 2018, stroke rehabilitation)6,000 µg/dayTwo 10-day courses, 20 days apart43 patients; raised plasma BDNF
Indexed clinical study (Dontsova 2015, psoriasis with metabolic syndrome)Printed as 600 mg/day; almost certainly 600 µg/dayCourse within complex therapy58 patients; intranasal
Rat studies25 µg/kg intranasal; up to 600 µg/kg in some modelsSingle to repeatedNeuroprotection, BDNF, behaviour
Commonly reported (nootropic use)200 to 600 µg/day of 0.1%, 1 to 3 doses10 to 14 days on, break; or 5 on 2 offUntested in controlled trials for this purpose
Commonly reported, N-acetyl Semax amidate200 to 900 µg/daySame patternsNo published human study of the variant

The single most common confusion is between the 0.1 percent and 1 percent products. A drop of the 1 percent solution is 500 micrograms, not 50, and the stroke regimen that circulates as "clinical dose" is a hospital dose in an acute setting.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

What side effects have been reported?

No study in this record's ledger reports adverse events or their frequency for semax. 37 indexed sources were searched. An absence in the literature is not evidence of safety or effect; it means the question has not been studied in a paper this record can cite.

Who Semax is discussed for, and the cautions that recur

The interest. Focus, motivation and recovery from mental fatigue, on the strength of its Russian indications for cognitive impairment and the BDNF story from animal work. Students, shift workers and people with attention difficulties are the audience that appears in communities.

Cautions that recur.

  • Anxiety and insomnia. The most common reasons given for stopping in community reports; the compound is not a stimulant but is alerting.
  • Nasal lining. Irritation and, with prolonged use, dryness or discoloration are reported; the Russian label lists irritation.
  • Pregnancy and children. The 0.1 percent form has been used in children in Russia under medical supervision; there is no data on pregnancy and no English-language paediatric data.
  • Psychiatric medication. Semax modulates dopamine and serotonin signalling in animals; interactions with antidepressants, stimulants or antipsychotics have not been studied.
  • The acetylated variant. Whatever its marketing, N-acetyl Semax amidate has no human study at all; every claim about it is borrowed from Semax.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Biomarkers measured in studies

Laboratory and clinical measures the studies report tracking, including which hormones did and did not change.

  • Clinical trial humans n = 43 2018 Human clinical trial
    Administration of semax, regardless of the timing of rehabilitation, increased BDNF plasma levels which remained high during the whole study period.
    Source pmid-29798983 · quoted verbatim from the abstract
  • Human study humans 2020 Observational, human
    The present study was aimed at the assessment of effects of anxiolytic Selank and nootropic Semax on the whole-brain resting-state functional connectivity (FC) of each of the predefined regions of interest (ROIs) in 52 healthy participants.
    Source pmid-32342318 · quoted verbatim from the abstract
  • Human study humans n = 58 2015 Observational, human
    It was found that the inclusion of semax in complex treatment of patients with psoriasis complicated by metabolic syndrome led to a decrease in the initially elevated serum levels of total cholesterol, triglycerides, LDL cholesterol and to an increase in the initially reduced levels of HDL cholesterol, in contrast to the standard treatment, which did not produce any statistically significant effect on the levels of total cholesterol, triglycerides, LDL cholesterol, and HDL cholesterol in the blood serum.
    Source pmid-27051926 · quoted verbatim from the abstract
  • Animal study rats 2024 Animal, preclinical
    Stressed and control male adult Sprague-Dawley rats received daily intraperitoneal injections of saline or a low dose (60 nmol/kg of body weight (BW)) of Semax or MTII.
    Source pmid-39442746 · quoted verbatim from the abstract
  • Animal study rats 2021 Animal, preclinical
    Administration of Semax or ACTH(6-9)PGP (100 μg/kg) to rats 30 min before ARS attenuated ARS-induced behavioral alterations.
    Source pmid-34576218 · quoted verbatim from the abstract
  • Animal study rats 2021 Animal, preclinical
    Thus, peptide Semax can prevent behavioural deficits caused by altered 5-HT levels during development.
    Source pmid-33418449 · quoted verbatim from the abstract

Reported interactions

Sentences in which the compound is studied alongside another agent. Read the quotation: the word interaction can also be statistical.

  • Human study humans n = 58 2015 Observational, human
    It was studied the possibility of correcting lipid metabolism in patients with psoriasis and concomitant metabolic syndrome (MS) by using additional treatment with semax.
    Source pmid-27051926 · quoted verbatim from the abstract
  • In vitro study humans 2016 Mechanistic, in vitro
    At physiological pH, the main complex species formed by Ac-Semax, [CuLH -2 ] 2- , consists in a distorted CuN 3 O chromophore with a weak apical interaction of the methionine sulphur.
    Source pmid-27586814 · quoted verbatim from the abstract

What happens after a dose, and what people report over weeks

Measured. Very little in people. The peptide itself is cleared within minutes; effects in animals are attributed to gene-expression changes that persist for hours after the drug is gone. In stroke patients, plasma BDNF rose over ten-day courses.

Commonly reported, untested. Users describe effects within fifteen to thirty minutes of a nasal dose lasting several hours, and a cumulative sense of improved mood over a course. Tolerance and rebound are debated in communities; no study addresses either.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Study durations

Treatment and follow-up periods as stated in each abstract.

  • Randomized controlled trial humans n = 27 2007 Human clinical trial
    Durations stated: 10 day; 2 weeks
    The drug was administered intranasally in two 10-day-long courses with 2-weeks break in daily dose of 12 mg.
    Source pmid-18379501 · quoted verbatim from the abstract
  • Controlled clinical trial humans n = 30 1997 Human clinical trial
    Durations stated: 10 days
    The most effective daily doses were 12 mg for patients with strokes of moderate severity and 18 mg for patients with severe strokes (treatment course--5 and 10 days).
    Source pmid-11517472 · quoted verbatim from the abstract, emphasis added
  • Human study humans n = 58 2015 Observational, human
    Durations stated: 10 days
    In group 1, 58 patients received conventional therapy, while 60 patients in group 2 received the same with additional 0.1% semax solution intranasally 600 mg/day for 10 days.
    Source pmid-27051926 · quoted verbatim from the abstract, emphasis added
  • Animal study rats 2021 Animal, preclinical
    Durations stated: 7 days; 21 days
    Mexidol (100 mg/kg) was administered intraperitoneally, and Semax (25 μg/kg) was administered intranasally, for 7 days each.
    Source pmid-33806692 · quoted verbatim from the abstract, emphasis added
  • Animal study rats 2021 Animal, preclinical
    Durations stated: 40 weeks
    Rat pups received FA or vehicle injections on postnatal days 1-14, a time period equivalent to 27-40 weeks of human foetal age.
    Source pmid-33418449 · quoted verbatim from the abstract, emphasis added

Routes studied

Routes of administration named in each study.

  • Human study humans n = 58 2015 Observational, human
    administration by intranasal route reported
    In group 1, 58 patients received conventional therapy, while 60 patients in group 2 received the same with additional 0.1% semax solution intranasally 600 mg/day for 10 days.
    Source pmid-27051926 · quoted verbatim from the abstract
  • Animal study rats 2024 Animal, preclinical
    administration by intraperitoneal route reported
    Stressed and control male adult Sprague-Dawley rats received daily intraperitoneal injections of saline or a low dose (60 nmol/kg of body weight (BW)) of Semax or MTII.
    Source pmid-39442746 · quoted verbatim from the abstract
  • Animal study rats 2024 Animal, preclinical
    administration by intraperitoneal route reported
    Here, we used high-throughput RNA sequencing (RNA-Seq) to identify differentially expressed genes (DEGs) in the brain frontal cortex of rat receiving intraperitoneal administration of ACTH-like peptides ACTH(4-7)PGP (Semax) and ACTH(6-9)PGP, or saline.
    Source pmid-39418522 · quoted verbatim from the abstract
  • Animal study rats 2021 Animal, preclinical
    administration by intranasal, intraperitoneal route reported
    Mexidol (100 mg/kg) was administered intraperitoneally, and Semax (25 μg/kg) was administered intranasally, for 7 days each.
    Source pmid-33806692 · quoted verbatim from the abstract
  • Animal study rats 2021 Animal, preclinical
    administration by intraperitoneal route reported
    We studied the effect of intraperitoneal administration ACTH (4-7) -PGP in doses of 5, 50, 150, and 450 μg/kg to Wistar male rats 12-15 min before modeling restraint stress on the morphofunctional state of the colon.
    Source pmid-33459919 · quoted verbatim from the abstract
  • Animal study mice n = 2 2004 Animal, preclinical
    administration by subcutaneous route reported
    DBA/2, CBA mice, and their F1 hybrids (first series) and 101/HY and C3H mice (second series) were injected as neonates (2-7 days of life) with Semax (sc., 7 microg per animal).
    Source pmid-15658043 · quoted verbatim from the abstract

Weight-normalized doses, as published

Per-kilogram figures exactly as each study published them, for the species it studied.

  • Animal study rats 2021 Animal, preclinical
    Weight-normalized doses as published: 25 μg/kg
    Mexidol (100 mg/kg) was administered intraperitoneally, and Semax (25 μg/kg) was administered intranasally, for 7 days each.
    Source pmid-33806692 · quoted verbatim from the abstract, emphasis added
  • Animal study rats 2020 Animal, preclinical
    Weight-normalized doses as published: 200 μg/kg
    Deltalicin in a dose 100 μg/kg and Semax in a dose 200 μg/kg as well as sulodexide corrected lipid metabolism disorders: the content of total cholesterol, triglycerides, LDL, index of atherogenicity decreased and HDL concentration increased.
    Source pmid-32246363 · quoted verbatim from the abstract, emphasis added

Weight-normalized figures above are reproduced exactly as each study published them, for the species it studied. Dose does not scale linearly with body mass between species: metabolic rate, clearance and receptor density differ, and regulatory guidance uses allometric, not proportional, conversion. A mg/kg figure from a rat study is a fact about that rat study and nothing else.

What people report outside the literature

What circulates in user communities and clinic marketing, reported so a reader knows the figures and their origin. None of it has been tested in a trial, and none of it is a suggestion.

  • Outside Russian clinical use, Semax circulates as a nootropic: 0.1 percent nasal spray or drops at roughly 200 to 600 micrograms a day in one to three doses, often in courses of ten to fourteen days followed by a break, or on a five-days-on, two-days-off pattern. A vendor variant, N-acetyl Semax amidate, is sold at similar or higher doses and has no published human study of its own. Some users inject 100 to 300 micrograms subcutaneously. These figures follow the Russian label's 0.1 percent regimen for cognitive indications loosely, and the trial evidence behind that label is in the Russian literature rather than in anything a user can read.Editorial synthesis
    Editorial synthesis from general knowledge
  • Effects people report are sharper focus, improved mood and motivation, and a calmer kind of alertness without stimulant edge; reported side effects are nasal irritation, dryness or discoloration of the nasal lining, headache, difficulty sleeping if taken late, and increased anxiety in some. The Russian label lists nasal irritation as the main adverse effect. No indexed English-language study reports adverse-event frequencies.Editorial synthesis
    Editorial synthesis from general knowledge

Semax as a nasal solution: concentrations and what a spray delivers

Semax is usually sold pre-dissolved or as powder to be dissolved for intranasal use. The arithmetic is exact; what to use is not decided here.

ProductConcentrationPer dropPer metered spray
0.1% solution1 mg/mL~50 µg per drop (0.05 mL)~100 µg per 0.1 mL spray
0.5% solution5 mg/mL~250 µg per drop~500 µg per spray
1% solution10 mg/mL~500 µg per drop~1,000 µg per spray
30 mg powder in 10 mL3 mg/mL (0.3%)~150 µg per drop~300 µg per spray, the common vendor bottle

Metered pumps vary between 0.05 and 0.14 millilitres; the delivered dose depends on the pump, not only the concentration. Solutions are refrigerated once opened and are usually described as stable for a few weeks; peptides in aqueous solution degrade faster in warmth and light. The reconstitution calculator does the concentration arithmetic for powder.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Method note · shared across compounds

Reconstitution mathematics

Lyophilised peptide is supplied as a mass in a vial and dissolved in a stated volume of diluent. Two figures follow from that and nothing else:

  • Concentration = mass in vial ÷ diluent volume. A 5 mg vial in 2 mL is 2.5 mg/mL, or 2,500 mcg/mL.
  • Volume for a given mass = that mass ÷ concentration. 250 mcg at 2,500 mcg/mL is 0.1 mL. On a U-100 insulin syringe, where 1 mL is 100 units, that is 10 units.

Study doses on this page are quoted as published, in the units the authors used. Converting between mcg, mg and IU, or between a mass and a syringe volume, is arithmetic; deciding a mass is not, and this page does not do it. The reconstitution calculator performs the conversion with the formula shown.

Method note · shared across compounds

Reading a certificate of analysis

A certificate of analysis is a laboratory report on one batch. Reading it means checking four things in order.

  1. Identity. Mass spectrometry should report an observed molecular mass matching the peptide's theoretical mass within the instrument's stated tolerance. A certificate with no mass spectrometry, or one that lists only the expected value, has not confirmed identity.
  2. Purity. HPLC purity is the area of the main peak as a share of all peaks, at a stated wavelength. It says nothing about what the other peaks are, and it is not a measure of quantity.
  3. Quantity. Net peptide content, by amino acid analysis or UV, is the fraction of the vial's mass that is peptide rather than counter-ions and water. A 5 mg vial at 80% net content holds 4 mg of peptide, and every concentration figure above changes accordingly.
  4. Provenance. The batch number on the certificate should match the vial, the laboratory should be named and independent of the seller, and the test date should be recent.

This page rates no supplier and links to none. It describes how to read the document.

Method note · shared across compounds

Equipment described in studies

Published human studies of injectable peptides report the same small set of materials: single-use insulin syringes with fixed needles, most often U-100 with 29 to 31 gauge needles; bacteriostatic water or sterile water for injection as diluent, with the choice stated in the methods; alcohol swabs; and refrigerated storage of reconstituted solution. Animal studies more often report intraperitoneal or intragastric administration and state the vehicle used. Where a study in this record's ledger names its materials or vehicle, that sentence appears under storage or routes above; where it does not, nothing is assumed here.

Storage and handling

Solutions are kept refrigerated at 2 to 8 °C, upright, protected from light, and are usually described as usable for two to four weeks after opening; some vendors state longer shelf lives for unopened bottles. Freezing and repeated warming degrade peptide solutions. Powder is refrigerated or frozen dry. Discard cloudy or discoloured solution.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

What is measured in the studies, and what is not

The Russian clinical studies measured neurological and functional scores in stroke, visual function in optic nerve disease, and in one 2018 study plasma BDNF. None measured cognition in healthy adults, and none that is indexed here reported systematic adverse-event counts. There is no monitoring schedule to borrow from; blood pressure and mood are what communities watch, and neither has been measured in a trial of this use.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Common mistakes in how Semax is discussed

  • "Approved in Russia" read as "proven". Registration there rests on Russian trials most readers cannot access and that have not been replicated elsewhere.
  • Quoting stroke doses for cognition. The 1 percent hospital regimen is ten times the 0.1 percent one.
  • Treating the acetylated variant as studied. It is not.
  • Calling it an ACTH analogue and expecting steroid effects. The fragment lacks the adrenal-stimulating region.
  • Assuming Semax and Selank are interchangeable. Different peptides, different parent molecules, different proposed effects.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Semax vs Selank, and how it sits among nootropic peptides

PeptideOriginProposed actionStatusHuman evidence
SemaxACTH(4-7) fragment + Pro-Gly-ProBDNF and monoamine modulation; alerting, cognitiveRegistered medicine in Russia; unlicensed elsewhereRussian trials in stroke, optic nerve disease; 1 indexed RCT
SelankTuftsin analogue + Pro-Gly-ProGABA-ergic and enkephalin modulation; anxiolyticRegistered medicine in Russia; unlicensed elsewhereRussian trials in anxiety disorders
DihexaAngiotensin IV analogueHGF/c-Met signalling; animal cognitionNever approved; no human trialsRat studies only
Cerebrolysin (for contrast)Porcine brain peptide mixtureNeurotrophic; stroke and dementiaApproved in several countries; not USMany trials; mixed results

Semax and Selank are siblings from the same institute with the same stabilising tail and opposite temperaments, one alerting and one calming, which is why they are so often compared and combined. The Selank vs Semax page lines up both records, and the Selank + Semax stack page covers the combination; Selank and Pinealon are the class peers in this reference.

Editorial synthesis Written from general pharmacology, the development record and what is commonly reported; not a cited finding. Cited findings on this page carry their own tier.

Other compounds in its class

Same class in the registry: DSIP, Selank. Each row shows what that compound's own record states; nothing is inferred across rows. Head-to-head evidence, where any exists, is on the comparison page: Selank vs Semax.

3 compounds in the neuropeptides nootropic class. Each row states what that compound's own record says; nothing is inferred across rows.
CompoundTierPublicationsRCTsRecord
Semax Human clinical trial 208 1 draft
DSIP Human clinical trial 559 7 draft
Selank Human clinical trial 96 2 draft

Studied in combination

Whether any indexed study tested Semax together with the compounds it is commonly combined with. A count of zero is the finding, not a gap in this page.

Is Semax approved anywhere?

Registry facts only. Jurisdiction-level status, compounding categories and sport prohibitions need their own cited documents before they appear here.

  • Russia: Semax is a registered medicine (intranasal solution, 0.1 and 1 percent), with indications that have included acute ischaemic stroke, recovery after stroke, optic nerve atrophy, and cognitive impairment; the 0.1 percent form has been used in children for attention disorders. The registration and its indications are Russian regulatory decisions and do not transfer elsewhere.Editorial synthesis
    Editorial synthesis from general knowledge · primary document to be added to the ledger
  • United States, European Union, United Kingdom: not approved or licensed. Sold as a research chemical; not a scheduled substance in these jurisdictions as far as public schedules show. It is not named on the WADA Prohibited List.Editorial synthesis
    Editorial synthesis from general knowledge · primary document to be added to the ledger

Open questions and limitations

What is genuinely unknown, stated plainly. A missing field is not evidence that the outcome is safe, effective, or established.

  • No study in this record's ledger reports dose-escalation schedules for Semax.
  • No study in this record's ledger reports exclusion criteria for Semax.
  • No study in this record's ledger reports adverse events or their frequency for Semax.
  • No study in this record's ledger reports onset or duration of effects for Semax.

Questions people ask

How fast does Semax work?

The peptide is cleared within minutes; effects in animals persist for hours through gene-expression changes. Users report effects within fifteen to thirty minutes lasting several hours. Nothing has been measured in healthy adults.

What is Semax?

A seven-amino-acid fragment of the hormone ACTH with a stabilising tail, developed in Russia and registered there as a nasal medicine for stroke recovery, optic nerve disease and cognitive impairment. Unlicensed outside Russia.

What does Semax do?

In animals it raises BDNF and its receptor in the hippocampus, modulates dopamine and serotonin, and protects neurons after ischaemia. In Russian clinical studies it improved functional outcomes after stroke and visual function in optic nerve disease. No controlled trial has measured cognition in healthy adults.

What is the Semax nasal spray dose?

The Russian 0.1 percent label uses roughly 200 to 600 micrograms a day in two or three doses; the 1 percent stroke regimen is about 6 milligrams a day in hospital. Community nootropic use follows the lower figure. None of these has been tested for cognition in healthy people.

What are the side effects of Semax?

The Russian label lists nasal irritation. Community reports add headache, insomnia when taken late, anxiety, and nasal dryness or discoloration with prolonged use. No indexed English-language study reports adverse-event frequencies.

Is Semax FDA approved?

No. It is not approved or licensed in the United States, European Union or United Kingdom. It is a registered medicine in Russia.

What is N-acetyl Semax amidate?

A vendor-modified form with an acetyl group and an amide tail, marketed as longer-acting. It has no published human study; everything said about it is borrowed from Semax.

Semax vs Selank: what is the difference?

Siblings from the same Russian institute with the same stabilising tail. Semax derives from ACTH and is alerting and cognitive; Selank derives from tuftsin and is anxiolytic. Different peptides, different proposed mechanisms.

Can Semax and Selank be used together?

They are combined in communities for focus with calm. No study has tested the pair; the stack page holds what exists.

How fast does Semax work?

The peptide is cleared within minutes; users report effects within fifteen to thirty minutes lasting hours. In stroke patients, BDNF rose over ten-day courses. Onset for cognitive effects in healthy adults has never been measured.

Does Semax raise cortisol?

No meaningful effect at studied doses: the fragment lacks the part of ACTH that stimulates the adrenal glands.

Is Semax a stimulant?

Not pharmacologically. It does not act on stimulant targets; users describe alertness without the edge of stimulants, and anxiety in some.

How many human studies of Semax exist?

Eight are indexed here, almost all Russian and small: stroke, optic nerve disease, psoriasis, and one 2018 study measuring BDNF. Many more exist in Russian-language journals that the indexes this site uses do not cover.

Is Semax banned in sport?

It is not named on the WADA Prohibited List. Athletes remain responsible for anything they take.

How should Semax be stored?

Refrigerated, upright, away from light; opened solutions are usually described as usable for two to four weeks. Discard cloudy or discoloured solution.

Can Semax be injected?

Some users inject it subcutaneously; the Russian medicine and all its trials are intranasal. No study compares routes.

Why is so little Semax research in English?

It was developed and registered in Russia, and most trials were published in Russian journals. Europe PMC indexes some by English abstract and misses others; independent replication outside Russia has not happened.

Sources

Full citations. Every claim above links to one of these by its id.

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    Pharmacological Aspects of Neuro-Immune Interactions.
    pmid-28875850 · · peer-reviewed
  11. 23
    [A comparative chemoreactome analysis of mexidol].
    pmid-28514338 · · peer-reviewed
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Reference card

Reference card · generated /compounds/semax
Compound
Semax, neuropeptides nootropic
Evidence tier
Human clinical trial
Indexed publications
208 · 1 RCTs · 3 other clinical trials
Approval
no registered development programme found
Routes reported
intranasal, intraperitoneal
Reviewed
Adam Mirando, PharmD,

Study figures are as published in each source and are not recommendations. Print or save this card with its date.

Last reviewed and what changed

Newest first. These are the record's own revision dates, and the same dates feed the sitemap.

  1. · Reviewed by Adam Mirando, PharmD, on 2026-09-24.
  2. · Hand curation: 1 alias-matched sources removed with 1 evidence rows and 1 claims. Flagged by the subject filter added to scripts/fetch_evidence.py the same day.
  3. · Registration date hedged: sources disagree by formulation. Stage 2 competitors and information gain written to the intent map.
  4. · Written guide (9 sections), FAQ to 16, mechanism, reported-use and regulatory editorial sections (Russian registration and non-approval elsewhere, documents pending), aliases added, intent-driven H1 and title. Third compound through the loop; second from the queue.
  5. · Claims drafted extractively from 37 ledger sources by scripts/draft_claims.py: 29 claims, 25 evidence-table rows. Status researched -> draft.
  6. · Claims drafted extractively from 37 ledger sources by scripts/draft_claims.py: 39 claims, 25 evidence-table rows. Status researched -> draft.
  7. · Metadata refreshed by scripts/fetch_evidence.py --refresh-meta: tier animal-preclinical -> human-clinical-trial.
  8. · Evidence fetched from Europe PMC and ChEMBL by scripts/fetch_evidence.py; claims not yet written.