nootropic 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 2026-01-30. Where a claim depends on a specific study, the study is described rather than over-claimed.
The compound was developed in the 1980s at the Institute of Molecular Genetics in Moscow, where it emerged from research on short ACTH fragments and their effects on the central nervous system. Russian pharmaceutical listings describe it as a nootropic and neuroprotective agent, most often formulated as nasal drops. It is not a marketed medicine in the United States or the European Union, and no pharmacopoeial monograph covers it. Consequently, most published clinical experience with the substance originates from a small number of research centres, mainly in Russia and neighbouring countries.
Pharmacological accounts link semax to melanocortin signalling and to modulation of neurotrophic factor expression, particularly brain-derived neurotrophic factor and nerve growth factor. Much of this evidence comes from rodent studies using intranasal delivery, a route chosen because it allows peptides to reach the central nervous system with limited systemic exposure. Whether the same mechanisms operate in humans at comparable magnitude remains an open question. The precise receptor or receptors responsible for the reported behavioural and neuroprotective effects have not been conclusively identified.
Solid semax is typically supplied as a lyophilised powder that is hygroscopic and sensitive to moisture, light, and repeated temperature cycling. Long-term storage of the dry peptide is generally recommended at approximately -20 degrees Celsius, while shorter working periods may use refrigeration at 2 to 8 degrees Celsius. Vials should remain tightly closed and desiccated when brought to room temperature, because condensation can damage the material before it is weighed. Dividing a batch into aliquots is preferable to thawing one container repeatedly.
Dissolution is normally performed in water, phosphate-buffered saline, or normal saline, since the peptide is freely soluble in aqueous media and is rarely handled with strong organic solvents. Solution pH should be kept near neutral, because extreme acidity or alkalinity accelerates backbone hydrolysis and encourages oxidation of the methionine side chain. Once dissolved, the material is less stable than the dry powder and is commonly divided into single-use portions and frozen. Buffers containing primary amines, such as Tris, are often avoided because of possible side reactions.
Purity assessment relies mainly on reversed-phase high-performance liquid chromatography, which separates the target heptapeptide from truncated sequences, deletion analogues, and oxidised forms. Mass spectrometry, usually coupled to liquid chromatography, confirms identity through the expected molecular ion and reveals modifications such as methionine sulfoxide formation. Amino acid analysis can verify composition, and tandem mass spectrometry supports sequence confirmation. Ultraviolet detection near 254 to 280 nanometres is convenient because the phenylalanine and histidine residues absorb in that region. Nuclear magnetic resonance is rarely used for routine release testing.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Free acid form of the heptapeptide; depends on terminal groups |
| Molecular mass | About 813.9 g/mol | Average mass used for mass spectrometry confirmation |
| Appearance | White to off-white solid | Supplied as a lyophilised powder; hygroscopic |
| Solubility class | Freely soluble in aqueous media | Water, saline, and phosphate buffers; limited organic solubility |
| Typical storage temperature | -20 degrees Celsius | Long term and dry; short working periods may use 2 to 8 degrees Celsius |
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.
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.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
The concept of hypoglycemia-associated autonomic failure (HAAF) or Cryer syndrome in diabetes posits that recent incidents of hypoglycemia causes both defective glucose counterregulation and hypoglycemia unawareness. By shifting glycemic thresholds for the sympathoadrenal (including epinephrine) and the resulting neurogenic responses to lower plasma glucose concentrations, antecedent hypoglycemia leads to a vicious cycle of recurrent hypoglycemia and further impairment of glucose counterregulation. In many cases (but not all), short-term avoidance of hypoglycemia reverses hypoglycemia unawareness in affected patients, although this is easier in theory than in clinical experience. In most cases, hypoglycemia is treated with sugary drinks or food. In severe cases, an injection of glucagon (a hormone with effects largely opposite to those of insulin) or an intravenous infusion of dextrose is used for treatment, but usually only if the person is unconscious. In any given incident, glucagon will only work once as it uses stored liver glycogen as a glucose source; in the absence of such stores, glucagon is largely ineffective. In hospitals, intravenous dextrose is often used.
==== Solid forms ==== For its main use as a fertilizer urea is mostly marketed in solid form, either as prills or granules. Prills are solidified droplets, whose production predates satisfactory urea granulation processes. Prills can be produced more cheaply than granules, but the limited size of prills (up to about 2.1 mm (0.083 in) in diameter), their low crushing strength, and the caking or crushing of prills during bulk storage and handling make them inferior to granules. Granules are produced by accretion onto urea seed particles by spraying liquid urea in a succession of layers. Formaldehyde is added during the production of both prills and granules in order to increase crushing strength and suppress caking. Other shaping techniques such as pastillization (depositing uniform-sized liquid droplets onto a cooling conveyor belt) are also used.
Apoptosis & Caspase 3 – PMAP The Proteolysis Map-animation Cytochrome+c at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Overview of all the structural information available in the PDB for UniProt: P99999 (Cytochrome c) at the PDBe-KB.
Sources: en.wikipedia.org
== Chemistry == Bremelanotide is a cyclic heptapeptide lactam analogue of α-melanocyte-stimulating hormone (α-MSH). It has the amino acid sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH, and is also known as cyclo-Ac-[Nle4,Asp5,D-Phe7,Lys10]α-MSH-(4-10) (a substitutional name). Bremelanotide is an active metabolite of melanotan II that lacks the C-terminal amide group. Aside from melanotan II and endogenous melanocyte-stimulating hormones like α-MSH, other peptide analogues of the same family as bremelanotide include afamelanotide (NDP-α-MSH), modimelanotide, and setmelanotide.
=== Muscle Media === In 1997, Phillips was eager to expand his empire beyond the bodybuilding industry. MM2K changed from targeting the hardcore bodybuilder to the more mainstream exercise participant, and the July 1997 issue saw the magazine redubbed simply as Muscle Media. While Muscle Media 2000 had a distribution of 500,000 copies per issue at its peak, the change in direction alienated many traditional readers, and sales numbers reportedly declined sharply afterwards. Publication finally ceased in 2004 after the EAS company was sold a second time.
==== 3200–3299 ==== A3 Trunk Road (Robin Hood Way (South) Service Road, Kingston upon Thames) (Prescribed Routes) Order 1993 (S.I. 1993/3201) Town and Country Planning (Fees for Applications and Deemed Applications) (Scotland) Amendment Regulations 1993 (S.I. 1993/3211) Lottery Duty Regulations 1993 (S.I. 1993/3212) Plant Health (Great Britain) (Amendment) (Potatoes) Order 1993 (S.I. 1993/3213) Upper Spey and Associated Waters Protection (Renewal) Order 1993 (S.I. 1993/3216) A6 Trunk Road (Rushden and Higham Ferrers Bypass) Order 1993 (S.I. 1993/3217) A6 Trunk Road (Rushden and Higham Ferrers Bypass) (Detrunking) Order 1993 (S.I. 1993/3218) Occupational Pension Schemes (Transitional Provisions) (Amendment) Regulations 1993 (S.I. 1993/3219) Retirement Benefits Schemes (Continuation of Rights of Members of Approved Schemes) (Amendment) Regulations 1993 (S.I. 1993/3220) Retirement Benefits Schemes (Tax Relief on Contributions) (Disapplication of Earnings Cap) (Amendment) Regulations 1993 (S.I. 1993/3221) Exempt Entertainments (Variation of Monetary Limit) Order 1993 (S.I. 1993/3222) Lotteries Regulations 1993 (S.I. 1993/3223) Lotteries (Gaming Board Fees) Order 1993 (S.I. 1993/3224) Banking Coordination (Second Council Directive) (Amendment) Regulations 1993 (S.I. 1993/3225) Friendly Societies Act 1992 (Commencement No. 7 and Transitional Provisions and Savings) Order 1993 (S.I. 1993/3226) Utilities Supply and Works Contracts (Amendment) Regulations 1993 (S.I. 1993/3227) Public Services Contracts Regulations 1993 (S.I. 1993/3228) Land Registration Fees Order 1993 (S.I.
Sources: en.wikipedia.org
== Cellular function == As an important actin regulator, gelsolin plays a role in podosome formation (along with Arp3, cortactin, and Rho GTPases). Gelsolin also inhibits apoptosis by stabilizing the mitochondria. Prior to cell death, mitochondria normally lose membrane potential and become more permeable. Gelsolin can impede the release of cytochrome C, obstructing the signal amplification that would have led to apoptosis. Actin can be cross-linked into a gel by actin cross-linking proteins. Gelsolin can turn this gel into a sol, hence the name gelsolin.
This is in contrast to inhibitors of all three isoenzymes of 5α-reductase like dutasteride, which can reduce DHT levels in the entire body by more than 99%. In addition to inhibiting 5α-reductase, finasteride has also been found to competitively inhibit 5β-reductase (AKR1D1). However, its affinity for the enzyme is substantially less than for 5α-reductase (an order of magnitude less than for 5α-reductase type I) and hence is unlikely to be of clinical significance. As of 2012, the tissues in which the different isozymes of 5α-reductase are expressed are not fully clear. This is because different investigators have obtained varying results with different reagents, methods, and tissues examined. However, the different isozymes of 5α-reductase appear to be widely expressed, with notable tissues including the prostate gland, seminal vesicles, testes, epididymides, skin, hair follicles, liver, kidneys, and brain, among others. By inhibiting 5α-reductase and thus preventing DHT production, finasteride reduces androgen signaling in tissues like the prostate gland and the scalp. In the prostate, this reduces prostate volume, which improves BPH and reduces the risk of prostate cancer. Finasteride reduces prostate volume by 20 to 30% in men with benign prostatic hyperplasia. Inhibition of 5α-reductase also reduces epididymal weight, and decreases motility and normal morphology of spermatozoa in the epididymis.
Mitral stenosis is uncommon and not as age-dependent as other types of valvular disease. Mitral insufficiency can be caused by dilation of the left heart, often a consequence of heart failure. In these cases, the left ventricle of the heart becomes enlarged and causes displacement of the attached papillary muscles, which control the mitral.
Sources: en.wikipedia.org
It is described as a synthetic analogue of the ACTH(4–10) fragment, a short segment of adrenocorticotropic hormone. Its sequence differs from that fragment and includes two proline residues, which influence stability and behaviour in solution.
It appears in Russian pharmaceutical listings as a nasal formulation, but it is not an authorised medicine in the United States or the European Union. Outside those markets it is normally encountered as a research chemical rather than a prescription product.
Laboratory and animal work points to melanocortin signalling and changes in neurotrophic factor levels, especially brain-derived neurotrophic factor. The exact receptor targets and the degree to which these findings transfer to humans are still unresolved.
Dry powder is usually kept at about -20 degrees Celsius for long-term storage and at 2 to 8 degrees Celsius for short working periods. Containers should stay sealed and protected from light and moisture to limit degradation.