Semax

Technical data

CAS

80714-61-0

Molecular formula

C37H51N9O10S

Molecular weight

813.93 g/mol

Identity and composition

Semax is a synthetic heptapeptide studied in research models for its potential nootropic and neuroprotective effects. It corresponds to an analog of the ACTH(4-10) fragment, stabilized with a C-terminal Pro-Gly-Pro extension. Product for research use.

Chemical identity data (verifiable reference):

• CAS: 80714-61-0
• Molecular formula: C37H51N9O10S
• Molecular weight: 813.9 g/mol
• Sequence: Met-Glu-His-Phe-Pro-Gly-Pro (heptapeptide; ACTH(4-10) analog with C-terminal Pro-Gly-Pro extension)
• Synonyms: SEMAX, ACTH(4-7)-Pro-Gly-Pro, MEHFPGP

Unlike the full ACTH molecule, Semax is described as lacking the corticotropic (endocrine/steroidogenic) activity of the parent peptide.

Mechanism of action

Semax is a heptapeptide derived from the ACTH(4-10) fragment whose active core is stabilized by a C-terminal Pro-Gly-Pro tripeptide, which is described as a factor that confers resistance to enzymatic degradation. According to the literature, it does not retain the corticotropic activity of full-length ACTH.

In preclinical rodent models, systemic or intranasal administration has been associated with rapid and region-specific changes in the expression of neurotrophin genes, in particular brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF), in the hippocampus and frontal cortex. In preclinical studies, stimulation of BDNF expression has been observed in different areas of the rat brain (PMID:14556513) and a time- and region-dependent (multidirectional) regulation of NGF and BDNF gene expression in hippocampus, frontal cortex and retina (PMID:19662538).

These neurotrophin-linked effects are the mechanism most frequently cited for its reported nootropic and neuroprotective actions. Claims about specific downstream signaling pathways should be considered preliminary.

Pharmacokinetics

No pharmacokinetic values were confirmed from a primary source in this review. The literature describes that the C-terminal extension Pro-Gly-Pro increases metabolic stability relative to the native ACTH fragment, and intranasal administration is frequently reported. However, specific values of half-life or bioavailability in humans were not verified, so these parameters remain uncharacterized here.

Scientific evidence

The available evidence is mostly preclinical and preliminary. Most of the published data come from gene-expression and behavioral studies in rodents. In these models, the induction of neurotrophins has been investigated as a proposed mechanistic basis (PMID:14556513; PMID:19662538).

Semax is described in the literature as an ACTH(4-10) analog developed in Russia and studied for nootropic and neuroprotective effects. It is reported to be registered for clinical use in Russia and neighboring countries for indications such as ischemic stroke, cognitive impairment, and optic nerve disorders; however, this regulatory status could not be independently confirmed against a primary regulatory source in this review, and it does not have FDA or EMA approval.

No reference Western or international randomized controlled clinical trial data were located here, so any claim of efficacy must be considered unestablished outside the Russian regulatory context.

Research applications

Product for research use.

Ideal for:

• Preclinical in vitro and in vivo studies on peptides derived from melanocortins.
• Research on gene expression of neurotrophins (BDNF, NGF) in animal models.
• Laboratory work on ACTH(4-10) analogs and peptide stability.

Not applicable for:

• clinical use, diagnostic use, or therapeutic use.
• Self-administration of any kind.
• Clinical use outside an authorized research framework; it is not approved by the FDA or the EMA.

Research protocols

The literature consulted does not include citation-validated dose figures for studies in models, so no numerical amounts are specified here.

Qualitatively, in the preclinical literature administration is described via systemic and intranasal routes in rodent models (PMID:14556513; PMID:19662538). The specific protocols for dose, frequency, and route must be defined according to each laboratory's experimental design and the corresponding primary literature. No verified human dosing data are available.

Reconstitution

General standard laboratory guide for lyophilized peptides:

• Reconstitute with bacteriostatic water (water with approximately 0.9% benzyl alcohol) for preparations intended for multiple withdrawals, or with sterile water for single-use research.
• Add the diluent slowly down the wall of the vial, letting it run over the powder; avoid directing the stream directly at the lyophilizate.
• Do not shake vigorously; swirl the vial gently until complete dissolution to preserve the integrity of the peptide.
• Calculate the diluent volume according to the desired concentration for the 5 mg, 10 mg, or 30 mg presentation.

Stability and storage

Standard laboratory handling:

• Lyophilized: the sealed powder is usually kept stable for prolonged periods when stored frozen and protected from light and moisture. For short-term storage it can be kept refrigerated.
• Reconstituted: once in solution, store refrigerated (approximately 2-8 °C) and use within a short period; for longer periods, aliquoting and freezing is recommended, avoiding repeated freeze-thaw cycles.
• Minimize exposure to room temperature and light during handling.

Safety profile

A well-documented human safety profile from controlled trials was not verified in this review. The safety, adverse-event and long-term human use data remain insufficiently characterized in the accessible peer-reviewed sources.

In preclinical studies, the endocrine effects associated with ACTH were not reported. As no confirmed controlled clinical profile exists, it is not possible to detail documented contraindications. It must be handled solely as research material, with standard laboratory precautions.

Comparative context

As an ACTH(4-10) analog, Semax retains —according to the literature— the central nervous system modulating activity of that fragment, while lacking the endocrine (corticotropic) activity of full-length ACTH.

It is frequently grouped among the melanocortin-derived neuropeptides. A related peptide also developed in Russia, Selank, is an anxiolytic analog of tuftsin, distinct in sequence and in reported activity. The main difference is its origin and profile: Semax is studied for nootropic/neuroprotective effects linked to neurotrophins, while Selank is described with an anxiolytic profile.

History and development

Semax was developed in Russia and is described in the literature as an analog of the ACTH(4-10) fragment, studied for its nootropic and neuroprotective effects. Most of the published evidence is preclinical in nature, focused on gene expression and behavioral studies in rodents.

It is reported to be registered for clinical use in Russia and neighboring countries for indications such as ischemic stroke, cognitive impairment and optic nerve disorders; however, this regulatory status could not be confirmed against a primary regulatory source in this review, and it has neither FDA nor EMA approval.

FAQ

Customer reviews

Average rating: 4.9 out of 5, based on 17 customer ratings.

Certificate of analysis per batch

Semax lots with certificate of analysis published in the COA catalog:

• Lot EXO010626029A — 30 mg, issued 2026-05-30
• Lot EXO010626029C — 5 mg, issued 2026-05-30

Scientific references (3)

Peer-reviewed literature on Semax, with its PubMed identifier when available:

• Semax and its metabolites have an effect on the dopaminergic system (Dolotov OV, et al. · Neurochemical Research · 2005) — Study on the mechanism of action of Semax in the dopaminergic system. PMID 16362768.
• The efficacy of semax in the treatment of patients at different stages of ischemic stroke (Gusev, et al. · Zhurnal Nevrologii i Psikhiatrii imeni S.S. Korsakova · 2018) PMID 29798983.
• Brain Protein Expression Profile Confirms the Protective Effect of the ACTH(4-7)PGP Peptide (Semax) in a Rat Model of Cerebral Ischemia-Reperfusion (Sudarkina, et al. · International Journal of Molecular Sciences · 2021) PMID 34201112.

Otras presentaciones de Semax

• NA Semax Amidate
• Semax + Selank

Guides and articles about Semax

Lecturas del blog de EXOMA que la editorial asoció a este compuesto:

• Semax in Mexico: heptapeptide analog of ACTH (4-10) in neuropeptide research
• Cerebrolysin: Neuroprotection and Neuroplasticity with Peptides

Other related research peptides

• Semax + Selank
• Adamax
• Cerebrolysin
• NA Selank Amidate
• NA Semax Amidate
• P21
• P21-Adamantane
• PE 22-28
• Selank