Peptide · Research Monograph · Synthetic heptapeptide analog of ACTH(4-10)

Semax

Cognitive Function Studies

Also known as N-Acetyl Semax

Semax is a seven amino acid peptide developed at a Russian research institute. Part of its sequence comes from ACTH, a hormone, and the rest is a short tail that keeps enzymes from breaking it down. Research in rodent models has measured BDNF, a protein involved in neuron growth, along with dopamine and serotonin activity. Despite the ACTH origin, it shows no stress hormone activity in testing.

Formula
C37H51N9O10S
Mol. weight
813.93 Da
Length
7 residues
Size
10mg
View product & pricing → Lot records & COAs

For laboratory research use only - not for human or animal use

Semax vial from the Eon Peptides research catalog
Semax · 10mg · catalog photograph
Available in the Eon catalog - Semax from $60.00 View certificate of analysisAccurate Test Labs · 99.99% purity · Lot SEM-090226-10

The molecule, in three dimensions

C37H51N9O10S813.93
Drag to turn
Residues · hover to locate7 residues
Heavy atoms
57
Bonds
60
Composition
C37 N9 O10 S1
Rings
4
Metal centre
None
Chain length
7 residues

Every heavy atom is placed from the sequence with ideal bond lengths and angles, so the connectivity is exact. The pose is idealised, an extended chain, and is not a measured conformation. Identity for the lot in stock is confirmed by LC-MS on its certificate.

Structure viewer →

Molecular data

Molecular formulaC37H51N9O10S
Molecular weight813.93 Da
SequenceMet-Glu-His-Phe-Pro-Gly-Pro
Sequence length7 residues
Physical formLyophilized Powder
Available sizes10mg

How it works

  1. Neurotrophic

    BDNF Modulation

    Brain-derived neurotrophic factor (BDNF) levels up to 1.4-fold baseline have been measured in specific brain regions, alongside neuronal survival and synaptic plasticity endpoints.

    • BDNF expression up to 1.4× measured
    • Neuronal survival and growth measured
    • Synaptic plasticity measured
  2. Neurotransmitter

    Serotonin & Dopamine Modulation

    Research demonstrates Semax modulates serotonergic and dopaminergic systems, influencing mood regulation, attention, and cognitive processing in preclinical models.

    • Modulates serotonin metabolism
    • Influences dopaminergic signaling
    • Affects noradrenergic pathways
  3. Neuroprotective

    Ischemic Models

    In ischemic stroke models, infarct volume, inflammatory gene expression and neuronal survival under oxygen deprivation are the recorded endpoints.

    • Infarct volume measured in stroke models
    • Anti-inflammatory gene modulation
    • Neuronal oxidative stress markers measured

What the research shows

  1. Cognitive

    Memory & Learning

    Cognitive function, memory consolidation and attention measures are recorded in animal models. The Russian pharmaceutical formulation has been approved there as a nootropic since 2011.

  2. Neuroprotection

    Cerebral Ischemia Models

    Infarct volume and neuronal survival are measured in cerebral ischemia models. The Russian pharmaceutical formulation is used clinically there; that use does not extend to this research material.

  3. Neurotrophic

    BDNF & Neurotrophin Signalling

    Neurotrophin and receptor expression are measured, alongside neuronal plasticity endpoints.

  4. Anti-Inflammatory

    Immune Modulation

    Lower pro-inflammatory cytokines and altered oxidative stress-related gene expression are measured in hippocampal tissue.

Specification

Strength10mg
Molecular FormulaC37H51N9O10S
Molecular Weight813.93 g/mol
Purity>99% (HPLC)
FormLyophilized Powder
SequenceMet-Glu-His-Phe-Pro-Gly-Pro
OriginSynthetic analog of ACTH(4-10)
TestingThird-party HPLC, Mass Spec, Endotoxin
Storage-20°C for up to 24 months
SolubilityWater-soluble
COAIncluded with every order
AppearanceWhite to off-white powder

How it's tested

Every lot of Semax released to the catalog carries a third-party certificate of analysis. 4 documented lots are on file for this compound, with reported HPLC purity from 99.08% to 99.99% (mean 99.52%), issued by Accurate Test Labs and Freedom Diagnostics. 4 of 4 certificates record identity as confirmed.

Documented lots
4
Reported purity
99.08% to 99.99%
Mean purity
99.52%
Issuing labs
Accurate Test Labs, Freedom Diagnostics

All certificates in the COA library →

Frequently asked questions

What is Semax and where does it come from?

Semax (Met-Glu-His-Phe-Pro-Gly-Pro) is a synthetic heptapeptide derived from the first four amino acids of adrenocorticotropic hormone (ACTH 4-10). It was developed at the Institute of Molecular Genetics of the Russian Academy of Sciences in the 1980s and has been approved in Russia as a prescription nootropic since 2011.

What has research shown about Semax?

Reported measures include BDNF levels up to 1.4-fold baseline, changes in serotonergic and dopaminergic systems, neuroprotective endpoints in ischemic stroke models, cognitive and memory measures in animal studies, and anti-inflammatory markers.

Is Semax FDA approved?

Semax is not approved by the FDA for any medical use in the United States. It is approved in Russia as a prescription medication for cognitive disorders and stroke recovery. In the US, it is available only as a research peptide for in vitro laboratory use.

How does Semax differ from N-Acetyl Semax?

N-Acetyl Semax (NASA) has an acetyl group added to the N-terminus, which raises stability and resistance to enzymatic degradation. Half-life is correspondingly longer than standard Semax.

How should Semax be stored?

Lyophilized Semax should be stored at -20°C for long-term stability (up to 24 months). Protect from heat and direct light.

Selected preclinical literature

8 published studies on Semax, limited by rule to animal models and cell-based (in vitro) work indexed in PubMed. Human trials, case reports and literature overviews are excluded. Titles appear as published and each links to its PubMed record; the list was resolved against PubMed on 2026-10-12. A listing describes what a study examined, not a property of the material supplied.

  1. Rats model and in vitro

    The Effect of Peptide Semax, an ACTH(4-10) Analogue, on Intracellular Calcium Dynamics in Rat Brain Neurons

    Bulletin of experimental biology and medicine, 2025. PubMed PMID 41171324 · doi:10.1007/s10517-025-06501-z

  2. Rats and Mice model and in vitro

    Semax peptide targets the μ opioid receptor gene Oprm1 to promote deubiquitination and functional recovery after spinal cord injury in female mice

    British journal of pharmacology, 2025. PubMed PMID 40692165 · doi:10.1111/bph.70122

  3. Rats model

    Antidepressant-like and antistress effects of the ACTH(4-10) synthetic analogs Semax and Melanotan II on male rats in a model of chronic unpredictable stress

    European journal of pharmacology, 2024. PubMed PMID 39442746 · doi:10.1016/j.ejphar.2024.177068

  4. Rats model

    Semax, synthetic ACTH(4-10) analogue, attenuates behavioural and neurochemical alterations following early-life fluvoxamine exposure in white rats

    Neuropeptides, 2021. PubMed PMID 33418449 · doi:10.1016/j.npep.2020.102114

  5. Rats model

    Morphofunctional State of the Large Intestine in Rats under Conditions of Restraint Stress and Administration of Peptide ACTH(4-7)-PGP (Semax)

    Bulletin of experimental biology and medicine, 2021. PubMed PMID 33459919 · doi:10.1007/s10517-021-05072-z

  6. Rats model

    Brain Protein Expression Profile Confirms the Protective Effect of the ACTH(4-7)PGP Peptide (Semax) in a Rat Model of Cerebral Ischemia-Reperfusion

    International journal of molecular sciences, 2021. PubMed PMID 34201112 · doi:10.3390/ijms22126179

  7. Rats model

    Composition of Colon Microbiota in Rats Treated with ACTH(4-7)-PGP Peptide (Semax) under Conditions of Restraint Stress

    Bulletin of experimental biology and medicine, 2020. PubMed PMID 32737723 · doi:10.1007/s10517-020-04886-7

  8. Rats model and in vitro

    Modulation of GABA- and Glycine-Activated Ionic Currents with Semax in Isolated Cerebral Neurons

    Bulletin of experimental biology and medicine, 2018. PubMed PMID 29577196 · doi:10.1007/s10517-018-4043-8

Full preclinical study index for Semax →

  • SelankStress Response Studies
  • DSIPStudied in sleep-architecture, stress-response, and endocrine research
  • PinealonTripeptide studied in neuronal oxidative-stress models
  • GLP-3 RTMetabolic Regulation Studies

For laboratory research use only. Not a drug, supplement, or medical product; not for human or animal use. All findings referenced are from published preclinical/laboratory research.