How to Reconstitute Semax
A laboratory guide to reconstituting Semax (ACTH(4-10) analogue, Met-Glu-His-Phe-Pro-Gly-Pro): the formal identifiers, the reconstitution procedure, and the animal and in vitro evidence behind the peptide.
Semax is the synthetic heptapeptide Met-Glu-His-Phe-Pro-Gly-Pro, also written as ACTH(4-7)PGP and described in the literature as an ACTH(4-10) analogue and a synthetic regulatory peptide [2][7]. It is supplied as a lyophilised (freeze-dried) solid for laboratory research, and reconstitution means dissolving that solid in a suitable solvent to produce a working solution of known concentration. The peptide is a member of the ACTH-like peptide family, and the work summarised below centres on its interactions with copper ion chemistry, with gene expression programmes in ischaemic brain tissue, and with the μ opioid receptor gene Oprm1 [2][5][8].
Reconstitution itself is a mechanical and volumetric procedure, not a pharmacological one: the lyophilised powder is brought to volume with a solvent, mixed until fully dissolved, and the resulting solution is handled according to the requirements of the assay it will be used in. The evidence block supporting this page does not specify a solvent, a concentration, or a storage condition for Semax, so no such values are given here. What the evidence does provide is the peptide's sequence and its documented behaviour in animal and in vitro systems, which is set out below.
Research Studies
Semax and copper-catalysed reactive oxygen species production in vitro
Semax was studied in vitro for its ability to inhibit copper-catalysed oxidation of amyloid beta (aβ) [2]. The paper reports that the peptide possesses a high affinity for Cu(II) ions, and that it is able to extract Cu(II) from Cu(II)-aβ species and to influence the redox behaviour of the complex [2]. The proposed context for this work is the Fenton-like generation of reactive oxygen species (ROS) linked to Cu(II)/Cu(I) redox cycling of the Cu(II)-aβ complex, which has been postulated to play a role in the molecular mechanism of neurotoxicity in Alzheimer's disease [2]. The reported outcome is a decrease in Cu(II)-catalysed ROS production and in the cytotoxicity of aβ, attributed to metal ion stripping and redox silencing [2]. These findings are in vitro and should be read as such.
Semax and amyloidosis in a transgenic Alzheimer's disease model
A study assessed Semax and a derivative of it in a transgenic animal model of Alzheimer's disease, examining behavioural characteristics and the development of amyloidosis [1]. The paper frames the work against the absence of remedies that are both effective in treating or significantly slowing the pathological process and sufficiently safe, and against the attention given to natural peptide drugs [1]. The findings reported are behavioural and amyloidosis-related outcomes in that transgenic model [1]. This is animal-model evidence; no human outcome is reported in the source.
Semax and gene expression in the penumbra-associated frontal cortex after tMCAO
Using RNA-Seq, researchers identified differentially expressed genes associated with ACTH(4-7)PGP (Semax) and ACTH(6-9)PGP in the penumbra-associated region of the frontal cortex of rats at 24 h after transient middle cerebral artery occlusion (tMCAO) [5]. The peptides significantly reduced profile disturbances caused by ischaemia across a large set of genes [5]. A companion analysis examined the same peptides in the penumbra-associated frontal cortex of rats at 24 h after tMCAO, following an earlier analysis at 4.5 h in the ipsilateral frontal cortex [6]. Both reports are rat studies; the readout is transcriptomic, not clinical.
Semax and intracellular calcium dynamics in rat brain neurons
Work on rat brain slices examined the effect of Semax on spontaneous fluctuations of intracellular calcium ion concentration in pyramidal neurons of hippocampal slices, and on the proton-induced increase in intracellular calcium in cerebellar granule cells of cerebellar slices [7]. Semax was applied at 1 μM in that preparation [7]. This is an ex vivo slice study in rat tissue.
Semax and the μ opioid receptor gene Oprm1 after spinal cord injury
In female mice, Semax was studied as a target of the μ opioid receptor gene Oprm1, with the reported mechanism involving promotion of deubiquitination and functional recovery after spinal cord injury [8]. The background given is that lysosomal membrane permeabilisation is exacerbated following spinal cord injury, leading to increased neuronal cell death, and that ubiquitination may affect lysosomal membrane permeabilisation by regulating the stability and functionality of lysosomal membranes [8]. This is a mouse study.
Semax and chronic unpredictable stress in male rats
Semax and Melanotan II, both described as ACTH(4-10) synthetic analogues, were examined for antidepressant-like and antistress effects in male rats in a model of chronic unpredictable stress [9]. The rationale given is that current antidepressant therapy has substantial limitations, and that stressful events and hyperactivity of the hypothalamic-pituitary-adrenal axis play an important role in the pathogenesis of depression [9]. This is a rat model of stress, not a clinical trial.
Semax within broader reviews of therapeutic peptides
Semax appears in the wider therapeutic-peptide literature. A narrative review of therapeutic peptides in gerontology examined mechanisms, clinical applications, evidence base, and safety profiles of peptides with demonstrated or potential applications in healthy aging and age-related conditions, targeting hallmarks of aging including metabolic dysfunction, telomere attrition, tissue repair impairment, and hormonal decline [4]. A separate review of therapeutic peptides in orthopaedics describes peptides as emerging adjuncts grounded in their ability to modulate molecular signalling networks, acting on pathways such as PI3K/Akt, mTOR, MAPK, TGF-β, and AMPK to influence tissue regeneration [10]. Neither review is a Semax-specific study, and neither reports a Semax clinical endpoint.
Comparison of the evidence types available for Semax
| Evidence type | Model or system | Reported readout | Source |
|---|---|---|---|
| In vitro | Cu(II)-aβ species | Cu(II) extraction, reduced ROS production, reduced aβ cytotoxicity | [2] |
| Animal | Transgenic Alzheimer's disease model | Behavioural characteristics and amyloidosis development | [1] |
| Animal | Rat tMCAO, frontal cortex | Differentially expressed genes at 4.5 h and 24 h | [5][6] |
| Ex vivo | Rat hippocampal and cerebellar slices | Intracellular calcium dynamics | [7] |
| Animal | Female mice, spinal cord injury | Oprm1 targeting, deubiquitination, functional recovery | [8] |
| Animal | Male rats, chronic unpredictable stress | Antidepressant-like and antistress effects | [9] |
Semax and the limits of the current evidence
The studies above are drawn from in vitro preparations, ex vivo rat brain slices, and animal models including transgenic mice, rats subjected to tMCAO, female mice with spinal cord injury, and male rats under chronic unpredictable stress [1][2][5][6][7][8][9]. The review literature places Semax within a broader class of therapeutic peptides but does not supply a Semax-specific clinical dataset [4][10]. No human dosing, pharmacokinetic, or efficacy data for Semax appear in the evidence block, and none is asserted here.
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Sources
- [1] The Potential of the Peptide Drug Semax and Its Derivative for Correcting Pathological Impairments in the Animal Model of Alzheimer's Disease — https://europepmc.org/article/PMC/PMC12755871
- [2] Semax, a Copper Chelator Peptide, Decreases the Cu(II)-Catalyzed ROS Production and Cytotoxicity of aβ by Metal Ion Stripping and Redox Silencing — https://europepmc.org/article/PMC/PMC12151629
- [3] Digitally Guided Hybrid Maxillary Expansion with Supragingival Mandibular Miniplates for Class III Correction in Late Adolescents: A Pilot Clinical Study — https://europepmc.org/article/PMC/PMC13116926
- [4] Therapeutic peptides in gerontology: mechanisms and applications for healthy aging — https://europepmc.org/article/PMC/PMC13095733
- [5] Genes That Associated with Action of ACTH-like Peptides with Neuroprotective Potential in Rat Brain Regions with Different Degrees of Ischemic Damage — https://europepmc.org/article/PMC/PMC12249733
- [6] ACTH-like Peptides Compensate Rat Brain Gene Expression Profile Disrupted by Ischemia a Day After Experimental Stroke — https://europepmc.org/article/PMC/PMC11673339
- [7] The Effect of Peptide Semax, an ACTH(4-10) Analogue, on Intracellular Calcium Dynamics in Rat Brain Neurons — https://pubmed.ncbi.nlm.nih.gov/41171324/
- [8] Semax peptide targets the μ opioid receptor gene Oprm1 to promote deubiquitination and functional recovery after spinal cord injury in female mice — https://pubmed.ncbi.nlm.nih.gov/40692165/
- [9] 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 — https://pubmed.ncbi.nlm.nih.gov/39442746/
- [10] Therapeutic Peptides in Orthopaedics: Applications, Challenges, and Future Directions — https://europepmc.org/article/PMC/PMC12753158