ACTH analog comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-02-19. Numbers and descriptions here follow the published literature rather than marketing material.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its design combines the ACTH(4-7) core fragment with a C-terminal Pro-Gly-Pro extension, a modification intended to improve stability and prolong activity. The molecule is hydrophilic, carries no lipid chains or glycosylation, and has a theoretical mass just over 810 daltons in its free form. All seven residues are proteinogenic amino acids, so no non-natural building blocks appear in the backbone. A free N-terminal methionine and C-terminal proline define the unmodified parent peptide.
The compound was developed during the 1980s at the Institute of Molecular Genetics in Moscow as part of research on fragments of adrenocorticotropic hormone. Early work examined short ACTH-derived sequences that retained neurotrophic effects while lacking the endocrine activity of the full hormone. Semax entered clinical use in Russia during the 1990s, where it received registration for several neurological indications. Outside that region it remained primarily a laboratory research material rather than an approved therapeutic. English-language literature on it grew more slowly and frequently cited the original Russian studies.
Terminology around the compound varies by source. It appears in catalogues and papers as Semax, as the heptapeptide ACTH(4-7)-Pro-Gly-Pro, and under various alphanumeric laboratory codes used by individual suppliers. These names refer to the same sequence but may imply different salt forms, purity grades, or counter-ions. Peptide databases usually list the free base mass, while product descriptions sometimes report acetate or trifluoroacetate salts with a different formula weight. Because naming conventions for research peptides are not standardised across vendors, checking the declared sequence and measured mass is more reliable than relying on a trade name alone.
Russian regulatory authorities approved the peptide for nasal administration, and it remains listed in the national pharmacopoeia under several trade names. Documented indications include acute ischemic stroke, transient ischemic attacks, traumatic brain injury, and certain ophthalmological and neurological conditions. Physicians also prescribe it for cognitive complaints in older patients, although the evidence base for that use is thinner. Outside Russia and a few neighboring states, the substance is not an approved medicine and is sold instead as a research chemical.
Later generations of the molecule include an N-acetylated form and an amidated form, both marketed online alongside the parent peptide. These variants differ in terminal chemistry and stability, and they are frequently discussed in the same breath even though they have not been compared in controlled trials. Supply outside formal healthcare systems comes largely from laboratories that synthesize peptides to order. Purity and identity of these materials vary widely, and no single body oversees the international trade.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic heptapeptide | ACTH(4-7) analogue |
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Free N terminus, unmodified side chains |
| Molecular weight | 813.9 Da | Free base; salt forms differ |
| Appearance | White to off-white powder | Lyophilised solid |
| Solubility | Freely soluble in water | Hydrophilic; polar solvents preferred |
Regulatory status differs sharply between jurisdictions. In Russia the peptide is registered as a prescription nasal preparation, while agencies such as the United States Food and Drug Administration have not approved it for any indication. Products sold elsewhere are typically labeled for laboratory research only, and such labels shift responsibility for safe handling to the purchaser. Because the same name covers pharmaceutical-grade nasal drops and bulk research powder, identity and purity documentation becomes the main practical concern when comparing sources.
Semax is a synthetic seven-amino-acid peptide whose sequence extends the ACTH(4-10) fragment with a C-terminal proline-glycine-proline tripeptide. The commonly cited sequence is Met-Glu-His-Phe-Pro-Gly-Pro, giving a molecular formula near C37H51N9O10S and a molecular weight close to 813.9 g/mol. It belongs to the broader class of synthetic ACTH fragments studied for central nervous system effects rather than for adrenal steroid stimulation. In practice the material appears as a lyophilized white powder for laboratory work or as a dilute saline solution in clinical settings.
Development is attributed to researchers at the Institute of Molecular Genetics in Moscow during the early 1980s, building on earlier Soviet work with ACTH fragments. Russian regulatory approval followed for intranasal use, and the compound has remained commercially available there for decades. Most published human data originate from Russian and, later, some Eastern European clinical reports, which are not always accessible in English translation. Outside that region the material is generally handled as a research chemical rather than a licensed medicine.
The compound is registered in Russia as a pharmaceutical product, most commonly formulated as a nasal solution, and has been used in that setting since the 1990s. Outside that jurisdiction it is generally handled as a research chemical rather than an approved medicine. Regulatory status therefore differs sharply between countries, and material sold internationally may not correspond to the Russian pharmaceutical formulation. Documentation with commercial samples is typically limited to a certificate of analysis covering purity and identity, not clinical status or local legal classification.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It corresponds to the ACTH(4-7) fragment extended at the C-terminus by a Pro-Gly-Pro tripeptide, an addition intended to slow enzymatic breakdown. The molecular formula is C37H51N9O10S and the molecular mass is approximately 814 daltons. In the literature it is often described as an ACTH(4-10) analog, although that label reflects a naming convention as much as a precise structural relationship. The compound was developed in Russia and remains most closely associated with that research tradition.
该化合物于二十世纪八十年代在俄罗斯被开发，相关工作由俄罗斯科学院分子遗传学研究所的研究团队主导。开发目标并非复制 ACTH 的完整激素活性，而是寻找保留其神经作用方向、同时去除促肾上腺皮质激素释放效应的短肽片段。研究记录显示，这一方向促成了多个相关短肽的合成与筛选，而 Semax 是其中被研究最广泛的一个。当地文献常以 Семакс 这一名称指代它。
研究兴趣主要集中在神经营养因子相关的路径上，包括脑源性神经营养因子与神经生长因子的表达变化。部分实验报告称在特定条件下观察到这些因子的水平上升，但具体信号通路和剂量依赖关系仍未完全厘清。多数公开数据来自细胞模型和动物实验，人体对照研究数量有限。因此，该化合物的作用机制在文献中属于活跃讨论，而非已经确立的定论。
Semax 是一种人工合成的七肽，氨基酸序列为 Met-Glu-His-Phe-Pro-Gly-Pro，单字母缩写记作 MEHFPGP。它被归类为促肾上腺皮质激素片段 ACTH(4-10) 的结构类似物，但并不天然存在于生物体内。母体片段 ACTH(4-10) 的序列为 Met-Glu-His-Phe-Arg-Trp-Gly，Semax 替换了中间两个残基，并在羧基端延长了 Pro-Gly-Pro 三肽。这种延长被普遍认为能提升分子对肽酶的耐受性。
== Biochemistry and functional relevance == Kinases mediate the transfer of a phosphate moiety from a high energy molecule (such as ATP) to their substrate molecule, as seen in the figure below. Kinases are needed to stabilize this reaction because the phosphoanhydride bond contains a high level of energy. Kinases properly orient their substrate and the phosphoryl group within their active sites, which increases the rate of the reaction. Additionally, they commonly use positively charged amino acid residues, which electrostatically stabilize the transition state by interacting with the negatively charged phosphate groups. Alternatively, some kinases utilize bound metal cofactors in their active sites to coordinate the phosphate groups. Protein kinases can be classed as catalytically active (canonical) or as pseudokinases, reflecting the evolutionary loss of one or more of the catalytic amino acids that position or hydrolyse ATP. However, in terms of signalling outputs and disease relevance, both kinases and pseudokinases are important signalling modulators in human cells, making kinases important drug targets. Kinases are used extensively to transmit signals and regulate complex processes in cells. Phosphorylation of molecules can enhance or inhibit their activity and modulate their ability to interact with other molecules. The addition and removal of phosphoryl groups provides the cell with a means of control because various kinases can respond to different conditions or signals.
Investigation on MMP inhibitors with phosphorus based zinc binding groups focused on α-biphenylsulfonylamino phosphonates. These inhibitors bind through two phosphonate oxygen atoms. Phosphonate inhibitors have been developed that exhibit selectivity for MMP-8 over other MMPs. Selective MMP-8 inhibitors could be useful in the treatment of acute liver disease and multiple sclerosis Phosphinic MMP inhibitors have been reported to target MMP-11 and MMP-13. MMP-13 plays a role in cartilage degradation in osteoarthritis. These phosphinate MMP inhibitors contain phenyl segments that are thought to be responsible for the selectivity to MMP-13. The phosphinic group of those inhibitors (R1R2 (O)OH) binds as a zinc ligand. R1 and R2 substituents affect the inhibition potency. Phosphinate inhibitors have been developed that showed high selectivity for MMP-11. Derivatives based on phenyl rings showed the best selectivity. MMP-11 could be a useful target for tumorgenesis in breast cancer.
According to Annex 13 of the Convention on International Civil Aviation, an aviation accident is an occurrence associated with the operation of an aircraft, which takes place from the time any person boards the aircraft with the intention of flight until all such persons have disembarked, and in which (a) a person is fatally or seriously injured, (b) the aircraft sustains significant damage or structural failure, or (c) the aircraft goes missing or becomes completely inaccessible. Annex 13 defines an aviation incident as an occurrence, other than an accident, associated with the operation of an aircraft that affects or could affect the safety of operation. A hull loss occurs if an aircraft is damaged beyond repair, is lost, or becomes completely inaccessible.
=== Physical properties === Technetium is a silvery-gray radioactive metal with an appearance similar to platinum, commonly obtained as a gray powder. The crystal structure of the bulk pure metal is hexagonal close-packed. Atomic technetium has characteristic emission lines at wavelengths of 363.3 nm, 403.1 nm, 426.2 nm, 429.7 nm, and 485.3 nm. The unit cell parameters of the orthorhombic Tc metal were reported when Tc is contaminated with carbon (a = 0.2805(4), b = 0.4958(8), c = 0.4474(5)·nm for Tc-C with 1.38 wt% C and a = 0.2815(4), b = 0.4963(8), c = 0.4482(5)·nm for Tc-C with 1.96 wt% C ). The metal form is slightly paramagnetic, meaning its magnetic dipoles align with external magnetic fields, but will assume random orientations once the field is removed. Pure, metallic, single-crystal technetium becomes a type-II superconductor at temperatures below 7.46 K (−265.69 °C; −446.24 °F). Below this temperature, technetium has a very high magnetic penetration depth, greater than any other element except niobium.
Sources: en.wikipedia.org
The stadium's name, Oakwell, originates from the well and oak tree that were on the site when first built. Oakwell is a multi-purpose sports development in Barnsley, South Yorkshire, used primarily by the club for playing its home fixtures, and its reserves. While the name 'Oakwell' generally refers to the main stadium, it also includes several neighbouring venues which form the facilities of the Barnsley academy – an indoor training pitch, a smaller stadium with seating on the south and west sides for around 2,200 spectators, and several training pitches used by the different Barnsley squads. Until 2003, the stadium and the vast amount of land that surrounds it was owned by Barnsley themselves; however, after falling into administration in 2002 the council purchased the main Oakwell Stadium to allow the club to pay its creditors and remain participants in the Football League. The stadium's capacity is 23,287.
== Thermochemical terminology == Although not substances, the thermochemical concepts entropy and enthalpy were assigned Chinese characters based on similar considerations. The 'fire' radical, 火, is used as the semantic category. The character for entropy, 熵 (pinyin: shāng), is derived from 商 (pinyin: shāng), which means 'quotient' in this context. This recognizes the Clausius equation for the differential change in entropy as the differential heat absorbed divided by the temperature: dS = dQ/T. The character for enthalpy, 焓 (pinyin: hán), is derived from 含 (pinyin: hán), which means 'to contain.' This character phonetically approximates the first syllable of 'enthalpy', and recognizes the definition of enthalpy as heat content.
The Moscow Metro operates a short monorail line (line 13). This line connects the Timiryazevskaya metro station and Ulitsa Sergeya Eisensteina (street), passing near the Exhibition of Achievements of National Economy (VDNKh) (and the Line 6 Metro station VDNKh). The monorail line opened in 2004. It permits above-ground transfers; a passenger does not need to pay any additional fare if they took another ride on the Moscow Metro within the most recent 90 minutes.
== Interactions == GPX1 has been shown to interact with ABL and GSH. A recently discovered suppressor for GPX1 is S-adenosylhomocysteine, which when accumulated in endothelial cells can cause tRNA(Sec) hypomethylation, reducing the expression of GPX1 and other selenoproteins. The decreased GPX-1 expression can then lead to inflammatory activating of endothelial cells, helping give rise to a proatherogenic endothelial phenotype.
In the United States, one of the only countries where CPA has not been approved for medical use, spironolactone is commonly used in transgender women instead. Bicalutamide has certain favorable properties as a potential alternative option to these antiandrogens in transgender females. For example, it is much more potent and selective as an AR antagonist than CPA and spironolactone. However, CPA may be a more potent antiandrogen than bicalutamide in the context of male levels of testosterone, due to its additional action of substantially suppressing testosterone levels at low doses. In transgender women who do not achieve their desired results or are unable to tolerate the side effects of other antiandrogens, switching to bicalutamide may be useful. The World Professional Association for Transgender Health (WPATH) Standards of Care for the Health of Transgender and Gender Diverse People Version 8 (SOC8), released in September 2022, recommends against the routine use of bicalutamide in transfeminine people due to lack of study and data on it in this population and safety concerns such as liver toxicity. Instead, the SOC8 recommends other more established and better-studied antiandrogens, like spironolactone, CPA, and GnRH modulators. Other less prominent transgender health guidelines are mixed in recommending against use of bicalutamide (UCSFTooltip University of California, San Francisco guidelines), cautiously allowing it (Fenway Health guidelines), and recommending it over other antiandrogens (Southern African HIV Clinicians' Society guidelines).
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide built from the ACTH(4-7) sequence plus a Pro-Gly-Pro tail. It belongs to the family of short ACTH fragments studied for nervous-system effects. Its backbone contains only standard amino acids.
It contains the 4-7 fragment of adrenocorticotropic hormone extended at the C terminus. That truncation removes the region associated with steroidogenic activity. The design intent was to keep neurotrophic properties while avoiding full hormonal effects.
No natural source of the intact heptapeptide is known. It is produced by solid-phase peptide synthesis. Some related ACTH fragments arise as hormone processing products, but the Pro-Gly-Pro extension is a designed addition rather than a natural sequence.
It originated at the Institute of Molecular Genetics in Moscow during the 1980s. The work was carried out by a Russian research group that specialized in peptide neuropharmacology.