ACTH(4-10) is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-07-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
Reported pharmacological work centers on neurotrophic signaling, including changes in BDNF and NGF expression in hippocampal tissue in animal models. Human data come largely from studies conducted in Russia, and how well those results generalize to other populations remains an open question. Regulatory status differs sharply by jurisdiction: Semax is a registered prescription medicine in Russia, while it holds no approved marketing status in the United States or the European Union. Outside such jurisdictions it is generally handled as a research chemical, which affects both documentation and quality expectations.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. It was developed as a fragment analog of adrenocorticotropic hormone, modeled specifically on the ACTH(4-10) region. The first four residues reproduce that fragment, while a Pro-Gly-Pro tripeptide is appended at the C-terminus. Work on the compound originated in Russia, where it entered clinical use as an intranasal preparation. Its sequence places it among short regulatory peptides studied for effects on the central nervous system rather than on the adrenal axis.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
The parent fragment ACTH(4-10) carries the sequence Met-Glu-His-Phe-Arg-Trp-Gly. Semax replaces the arginine and tryptophan positions with a proline-glycine-proline tail, giving Met-Glu-His-Phe-Pro-Gly-Pro. That change removes residues associated with adrenal stimulation, so the peptide does not drive cortisol release the way full ACTH does. This distinction shapes how the compound is grouped in the literature, where it sits with neuropeptides and peptide neuromodulators rather than with corticosteroids.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
Verification of a supplied batch generally combines a certificate of analysis with independent testing, because certificates are self-reported documents. A typical package includes a chromatographic trace, a mass spectrum, and a stated water or counter-ion content. Batch-to-batch consistency matters more than a single purity figure when results are compared across experiments. No single mandatory standard governs research-grade peptide release, so laboratories are expected to define their own acceptance criteria. Residual trifluoroacetate from purification is a frequently overlooked counter-ion.
Lyophilized material is chemically stable for extended periods when kept dry, cold, and protected from light. The powder is hygroscopic, so vials should be warmed to room temperature before opening to reduce condensation on the contents. Once dissolved, the peptide is far less stable because peptide bonds are susceptible to hydrolysis and the methionine residue can oxidize. Solutions are typically aliquoted and held at 2-8 °C for short intervals or frozen for longer ones, and repeated freeze-thaw cycles should be avoided.
The proposed mechanism centres on neurotrophic signalling rather than direct receptor activation. Semax is reported to increase expression of brain-derived neurotrophic factor and nerve growth factor in several brain regions, and to shift the balance between excitatory and inhibitory neurotransmitter systems. Interaction with melanocortin receptors has been suggested because of the parent ACTH fragment. Many of these findings come from rodent studies, and the extent to which they translate to human physiology remains an open question.
Scientific literature on semax is unevenly distributed. A substantial share of published work originates from a small number of laboratories in Russia, while independent replication elsewhere is limited. Human data consist mostly of small trials with short follow-up, and several reported outcomes rely on subjective rating scales. Questions about how much intact peptide reaches the central nervous system after nasal administration, and how long it persists there, are still unresolved. The compound is best described as an active research subject rather than a settled pharmacological agent.
Lyophilised powder is normally kept at -20 °C in a desiccated container, with some suppliers recommending -80 °C for long-term archival storage. Repeated freeze-thaw cycles are the most common cause of avoidable loss, so aliquoting before freezing reduces variability between working sessions. Dissolved peptide is far less stable than the dry solid and is usually prepared fresh or held briefly at 4 °C. Aqueous solutions support both hydrolysis of the backbone and oxidation of the N-terminal methionine, and these two routes dominate degradation under ordinary laboratory conditions.
Identity and purity are confirmed with reversed-phase high-performance liquid chromatography, typically monitored at 214 nanometres where the peptide bond absorbs. Mass spectrometry, either electrospray or MALDI-TOF, verifies molecular mass against the theoretical value and detects truncation or adduct formation. Amino acid analysis and peptide mapping provide additional confirmation when required. The most frequently reported impurities are deletion sequences from incomplete coupling, methionine sulfoxide from oxidation, and dimeric species formed through non-covalent aggregation. Impurity profiles depend strongly on the synthesis and purification route chosen by the producer.
All CHO cell lines are deficient in proline synthesis. Also, CHO cells do not express the epidermal growth factor receptor (EGFR), which makes them ideal in the investigation of various EGFR mutations. Furthermore, Chinese hamster ovary cells are able to produce proteins with complex glycosylations, post-translational modifications (PTMs) similar to those produced in humans. They are easily growable in large-scale cultures and have great viability, which is why they are ideal for GMP protein production. Also, CHO cells are tolerant to variations in parameters, be it oxygen levels, pH-value, temperature or cell density. Having a very low chromosome number (2n=22) for a mammal, the Chinese hamster is also a good model for radiation cytogenetics and tissue culture. Being the first cell line to be used for recombinant pharmaceutical production, regulatory concerns were raised with respect to Endogenous Retroviral Sequences (ERS). CHO cells contain about 1000 of these sequences and some of them are able to direct the synthesis of Intracisternal A-type particles and C-type particles. Also, low expression of reverse transcriptase was observed. However the majority of ERS are defective (stop codons in all reading frames) and contain large deletions of a putative retroviral genome.
Amyloidosis has a combined estimated prevalence of 30 per 100,000 persons with the three most common forms being AL, ATTR, and AA. The median age at diagnosis is 64. AL has the highest incidence at approximately 12 cases per million persons per year and an estimated prevalence of 30,000 to 45,000 cases in the US and European Union. AA amyloidoses is the most common form in developing countries and can complicate longstanding infections with tuberculosis, osteomyelitis, and bronchiectasis. AA amyloidosis is caused by an increase in extracellular deposition of serum amyloid A (SAA) protein. SAA protein levels can rise in both direct and indirect manners, through infection, inflammation, and malignancies. The most common causes of AA amyloidosis in the West are rheumatoid arthritis, inflammatory bowel disease, psoriasis, and familial Mediterranean fever. People undergoing long-term hemodialysis (14–15 years) can develop amyloidosis from accumulation of light chains of the HLA 1 complex which is normally filtered out by the kidneys. Wild-type transthyretin (ATTR) amyloidosis is found in a quarter of elderly at postmortem. ATTR is found in 13–19% of people experiencing heart failure with preserved ejection fraction, making it a very common form of systemic amyloidosis.
The major cell-matrix adhesion receptors are integrins and therefore the adhesome of cell-matrix adhesion is referred to as the integrin adhesome. Cell-cell adhesion is primarily mediated by cadherin receptors and therefore the adhesome of cell-cell adhesion is referred to as the cadherin adhesome or cadhesome. The first attempts to establish the set of proteins that participate directly ('bona fide' adhesome components) or affect indirectly ('associated' adhesome components) cell adhesion were based on mining of the primary research literature, and resulted in approximately 200 protein in either integrin or cadherin adhesomes. Later, unbiased proteomic approaches utilizing mass spectrometry have detected hundreds more proteins associated with integrin adhesions. However, a comparison of multiple proteomic studies of the integrin adhesome of fibroblasts attached to fibronectin found only 60 proteins common to all studies. Humphries and co-workers named these 60 proteins the 'consensus integrin adhesome'.
Distal membrane-arm assembly complex protein 1 is a protein that in humans is encoded by the DMAC1 gene (previously TMEM261). TMEM261 is also known as C9ORF123 and DMAC1, Chromosome 9 Open Reading Frame 123 and Transmembrane Protein C9orf123 and Distal membrane-arm assembly complex protein 1. TMEM261 is located at 9p24.1, its length is 91,891 base pairs (bp) on the reverse strand. Its neighbouring gene is PTPRD located at 9p23-p24.3 also on the reverse strand and encodes protein tyrosine phosphatase receptor type delta. TMEM261 has 2 exons and 1 intron, and 6 primary transcript variants; the largest mRNA transcript variant consisting of 742bp with a protein 129 amino acids (aa) in length and 13,500 daltons (Da) in size, and the smallest coding transcript variant being 381bp with a protein 69aa long and 6,100 Da in size. TMEM261 is a protein consisting out of 112 amino acids, with a molecular weight of 11.8 kDa. The isoelectric point is predicted to be 10.2, whilst its posttranslational modification value is 9.9.
The Great Oxygenation Event (GOE) is characterized by the disappearance of sulfur isotope mass-independent fractionation (MIF) in the sedimentary records at around 2.45 billion years ago (Ga). The MIF of sulfur isotope (Δ33S) is defined by the deviation of measured δ33S value from the δ33S value inferred from the measured δ34S value according to the mass dependent fractionation law. The Great Oxidation Event represented a massive transition of global sulfur cycles. Before the Great Oxidation Event, the sulfur cycle was heavily influenced by the ultraviolet (UV) radiation and the associated photochemical reactions, which induced the sulfur isotope mass-independent fractionation (Δ33S ≠ 0). The preservation of sulfur isotope mass-independent fractionation signals requires the atmospheric O2 lower than 10−5 of present atmospheric level (PAL). The disappearance of sulfur isotope mass-independent fractionation at ~2.45 Ga indicates that atmospheric pO2 exceeded 10−5 present atmospheric level after the Great Oxygenation Event. Oxygen played an essential role in the global sulfur cycles after the Great Oxygenation Event, such as oxidative weathering of sulfides. The burial of pyrite in sediments in turn contributes to the accumulation of free O2 in Earth's surface environment.
Sources: en.wikipedia.org
Traditionally, Escherichia coli is the choice bacterium to express eukaryotic and recombinant genes. E. coli is well understood and has a successful track record producing insulin, the artemisinin precursor artemisinic acid, and filgrastim (Neupogen). However, use of E. coli has limitations including misfolding of eukaryotic proteins, insolubility issues, deposition in inclusion bodies, low secretion efficiency, secretion to periplasmic space. Streptomyces offers potential advantages including superior secretion mechanisms, higher yields, a simpler end-product purification process, making Streptomyces an attractive alternative to E. coli and Bacillus subtilis. Streptomyces coelicolor, Streptomyces avermitilis, Streptomyces griseus, and Saccharopolyspora erythraea, are capable of secondary metabolite production. Streptomyces coelicolor has shown useful for the heterologous expression of proteins. Methods like "ribosome engineering" have been used to achieve 180-fold higher yields with S. coelicolor.
Amylopectin has seen a rise of use in biomedical applications due to its physiological factors, ease of availability, and low cost. Specifically, amylopectin has very advantageous biochemical properties due to its prevalence as a natural polysaccharide. This causes a high sense of biocompatibility with cells and molecules within the body. Amylopectin is also able to biodegrade to a high degree due to its high sense of crosslinking with 1,6 glycosidic bonds. The bonds easily broken down by the body can reduce molecular weight, expose certain regions, and interact certain bonds with clinical factors. Various physical, chemical, and enzymatic methods of modification have also been researched for amylopectin. These, generally, allow for enhanced and controllable properties which can be selected for the field of research performed. Amylopectin's main role, clinically, is within its integration in starch. Function and structure of amylopectin is based on its integration with amylose and other bounded molecules. Separating these molecules and isolated amylopectin is quite difficult for researchers to perform.
Mike Evans tied the record for consecutive seasons with at least 1,000 receiving yards, with 11. He shares this record with Jerry Rice. Evans also extended his own record of most such seasons to start his career. Aaron Rodgers became the fifth player to have 500 passing touchdowns. Trey McBride set the record for most receptions by a tight end in his first three seasons, with 221. The previous record of 216 was held by George Kittle. The Buffalo Bills became the first team to score at least 30 rushing touchdowns and at least 30 passing touchdowns in a season. Wild Card Round
AS9100 Revision C (2009), Quality Management System – Requirements for Aviation, Space and Defense Organizations The update of AS9100 from revision B to C is largely to address the following question: "Our supplier is repeatedly late on delivery and failing to meet our requirements, how is it possible that they still have their AS9100 certificate?" That is, the AS9100C changes are driven by repeated delivery of non-conforming product and repeated late delivery by organizations that held AS9100A/B certifications. Those organizations had documented controls that conformed to the standard, however, there were insufficient processes in place to assure effectiveness of those controls. The response in this AS9100 revision is to elevate the requirements for Risk Management and to make Risk Management an integrated theme throughout the standard. A major challenge to AS9100B-compliant organizations was the new AS9100 auditing standards defined in AS9101 Revision D, which eliminates the clause-based compliance checklist and requires organizations to provide evidence of effectiveness of their systems and processes. Summary of changes between AS9100B and AS9100C:
Sources: en.wikipedia.org
γ-Aminobutyric acid (GABA) prodrugs include progabide and tolgabide. Picamilon (N-nicotinoyl-GABA) has been claimed to be a prodrug of GABA, but has not actually been demonstrated to be converted into GABA. N-Benzoyl-GABA is of very similar chemical structure as picamilon and has also been claimed to be a prodrug of GABA, but this remains unclear similarly. Pivagabine (N-pivaloyl-GABA) was once thought to be a prodrug of GABA, but this proved not to be the case. Cetyl-GABA (GABA cetyl ester) is another prodrug of GABA. 4-Amino-1-butanol is known to be converted into GABA through the actions of aldehyde reductase (ALR) and aldehyde dehydrogenase (ALDH). 4-Amino-1-butanol is to GABA as 1,4-butanediol (4-hydroxy-1-butanol; 1,4-BD) is to γ-hydroxybutyric acid (GHB) (with 1,4-BD being a well-known prodrug of GHB). The metabolic intermediate γ-aminobutyraldehyde (GABAL) is also converted into GABA. A number of γ-hydroxybutyric acid (GHB) prodrugs are known. These include 1,4-butanediol (1,4-BD) and γ-butyrolactone (GBL), as well as the metabolic intermediate γ-hydroxybutyraldehyde (GHBAL).
80. Coll Antropol. 2005 Jun;29(1):321-5. Gastric pentadecapeptide BPC 157 promotes corneal epithelial defects healing in rats. Lazić R(1), Gabrić N, Dekaris I, Bosnar D, Boban-Blagaić A, Sikirić P. Author information: (1)Eye Clinic, Svjetlost, Zagreb, Croatia. ratimir.lazic@zg.htnet.hr We evaluated the role of human gastric pentadecapeptide BPC 157 in corneal epithelial defects healing in rats. 48 rats, in 4 groups (N=12). Total debridement of corneal epithelium preformed unilaterally and lesions stained and photographed. Animals medicated as follows: distilled water (control group) or BPC 157 2 pg/ml, 2 ng/ml, 2 microg/ml, 2 drops/rat eye started immediately after injury induction, every 8 hours up to 40 hours (i.e., at 0, 8, 16, 24, 32, 40 h). Lesions were photographed before application or sacrifice (at 48 h). Defect area was analyzed using a special program. Through 48 hour period a steady recovery is noted in controls. Recovery was markedly accelerated in eyes on microg- or ng-topical regimen of BPC 157 (p < 0.05). Of note, unlike control lesion present also after 48 h, these lesions disappeared already following 40 h (microg) or 48 h (ng) post-injury. BPC 157 was shown to be effective in promoting corneal defects healing in rats. Results were dose dependent.
Two-sample hypothesis tests are appropriate for comparing the two samples in which the samples are divided by the two control cases in the experiment. Z-tests are appropriate for comparing means under stringent conditions regarding normality and a known standard deviation. Student's t-tests are appropriate for comparing means under relaxed conditions when less is assumed. Welch's t-test assumes the least and is therefore the most commonly used two-sample hypothesis test in which the mean of a metric is to be optimized. While the mean of the variable to be optimized is the most common choice of estimator, others are regularly used. Fisher's exact test can be employed to compare two binomial distributions, such as a click-through rate.
(E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP or HMB-PP) is an intermediate of the MEP pathway (non-mevalonate pathway) of isoprenoid biosynthesis. The enzyme HMB-PP synthase (GcpE, IspG) catalyzes the conversion of 2-C-methyl-D-erythritol 2,4-cyclodiphosphate (MEcPP) into HMB-PP. HMB-PP is then converted further to isopentenyl pyrophosphate (IPP) and dimethylallyl pyrophosphate (DMAPP) by HMB-PP reductase (LytB, IspH). HMB-PP is an intermediate in the non-mevalonate pathway for the biosynthesis of the isoprenoid precursors isopentenyl pyrophosphate and dimethylallyl pyrophosphate. Most gram-negative bacteria, the photosynthetic cyanobacteria and green algae use only this pathway, while higher plants also use the mevalonate pathway. The enzyme 4-hydroxy-3-methylbut-2-en-1-yl diphosphate synthase uses two reduced ferredoxin proteins per molecule of the precursor MEcPP to convert it to HMB-PP:
Gs exerts its effects via two pathways. Firstly, it directly opens L-type calcium channels (LTCC) in the plasma membrane. Secondly, it renders adenylate cyclase activated, resulting in an increase of cAMP, activating protein kinase A (PKA) which in turn phosphorylates several targets, such as phospholamban, LTCC, Troponin I (TnI), and potassium channels. The phosphorylation of phospholamban deactivates its own function which normally inhibits SERCA on the sarcoplasmic reticulum (SR) in cardiac myocytes. Due to this, more calcium enters the SR and is therefore available for the next contraction. LTCC phosphorylation increases its open probability and therefore allows more calcium to enter the myocyte upon cell depolarisation. Both of these mechanisms increase the available calcium for contraction and therefore increase inotropy. Conversely, TnI phosphorylation results in its facilitated dissociation of calcium from troponin C (TnC) which speeds the muscle relaxation (positive lusitropy). Potassium channel phosphorylation increases its open probability which results in shorter refractory period (because the cell repolarises faster), also increasing lusitropy. Furthermore, in nodal cells such as in the SA node, cAMP directly binds to and opens the HCN channels, increasing their open probability, which increases chronotropy.
Sources: en.wikipedia.org
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.