ACTH(4–10) raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-01-04. Anything still debated is marked as such rather than presented as settled.
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.
Semax is supplied as a lyophilized powder that appears white to off-white. It dissolves readily in water, phosphate-buffered saline, and other aqueous media, which simplifies preparation of working solutions for laboratory use. The nasal products registered in Russia are dilute aqueous solutions, typically around 0.1 percent peptide by weight. Organic solvents are rarely necessary and can complicate handling. Because the peptide is hygroscopic, weighing should be performed quickly and with minimal exposure to ambient humidity.
Solid material is normally kept at minus 20 degrees Celsius in a sealed, desiccated container. Reconstituted solutions are less stable and are usually divided into single-use aliquots before freezing. Repeated freeze-thaw cycles are avoided because they promote aggregation and loss of activity. Light exposure is minimized by using amber glassware or foil wrapping. Published stability data for this peptide are sparse, so recommended storage conditions rest mainly on general practice for short synthetic peptides rather than on dedicated study.
Identity and purity are commonly assessed by reversed-phase high-performance liquid chromatography, with ultraviolet detection near 214 nanometers for the peptide backbone. Mass spectrometry, either electrospray or matrix-assisted laser desorption, confirms molecular mass and detects truncation or modification products. Amino acid analysis can verify composition. Because the sequence contains no strongly absorbing aromatic residue apart from phenylalanine, detection wavelengths are chosen carefully. Purity values above 95 percent are typical for research-grade material.
| 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 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.
Laboratory descriptions of the material are consistent across suppliers. It appears as a white to off-white lyophilized powder that dissolves readily in water and in polar organic solvents such as dimethyl sulfoxide. Aqueous solutions are clear and colorless at low concentrations. Because the peptide contains methionine, oxidation at the sulfur atom is a recognized degradation pathway, and handling notes usually call for protected, desiccated storage. Reported purity for research-grade lots is generally above 95 percent as measured by reversed-phase high-performance liquid chromatography.
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.
Identity and purity of Semax are established mainly by reversed-phase high-performance liquid chromatography coupled with mass spectrometry. The chromatographic trace gives a purity estimate as a percentage of total peak area, while electrospray or matrix-assisted laser desorption ionization confirms the molecular mass against the calculated value. Amino acid analysis and sequence-specific fragmentation provide further confirmation when a supplier's chain of custody is unclear. Vendors frequently quote a purity figure without stating the detection wavelength or the integration method, which limits how far one number can be compared with another.
Stability depends heavily on physical state. Lyophilized powder held dry, cold and dark retains its content over long periods, whereas dissolved peptide begins to change within days at room temperature. The most cited degradation route is oxidation of the methionine residue, which converts the peptide to a sulfoxide form that elutes differently on chromatography. Hydrolysis of amide bonds and adsorption onto container walls contribute smaller losses. Buffers that exclude oxygen from the headspace slow the oxidation pathway, but no single condition prevents all change indefinitely.
=== Lawsuits === On 12 January 2016, Dow Pharmaceutical Sciences and Valeant Pharmaceuticals North America LLC filed a lawsuit against Taro USA and Taro Industries, an Israel-based corporation. The lawsuit was filed for infringement upon their Onexton patent, by Taro attempting to submit an abbreviated new drug application (ANDA) to the Food and Drug Administration (FDA) for its generic 3.75% benzoyl peroxide and 1.2% clindamycin phosphate topical gel. The court concluded that Taro was guilty of attempting to submit an ANDA patent request before the Onexton patent expired. Perrigo settled its patent litigation with Valeant and Dow.
=== New Zealand in 1998 === In 1998 he walked from Cape Reinga in the North Island, to Bluff, at the southern tip of New Zealand; a distance of 1,500 miles (2,400 km). On the journey he walked through the active volcano at White Island, experienced earthquakes up to 4.9 on the Richter Scale, clambered over glaciers, swam with seals and reported on conservation biology projects involving endangered species. Information from the journey was posted on the Internet for schoolchildren in the U.S. via the Scholastic Corporation Scholastic Network. In December 2010 Skinner completed a book about the journey and conservation biology, New Zealand – 1500 miles on foot through – The Land of the Long White Cloud on an Internet website. In 1999 he obtained a PGCE (Postgraduate Certificate in Education) from Canterbury Christ Church University in Canterbury, England. In 2000 he worked as a secondary school science teacher at St. Edmund's School in Dover, teaching 11 to 16-year-olds. In 2001 he worked as a volunteer at a wildlife park, working on enrichment activities for animals. From 2001 until 2003 he worked part-time at a post office. During this time, he also taught science to primary school children, in a 'Link-Scientist' scheme run by the pharmaceutical company Pfizer, and took care of his son. In 2003 his mother died from pancreatic cancer, at the age of 59. This prompted him to write the story of the 6,000 miles (9,700 km) journey across Britain and America.
==== Monensin ==== In 1980, Still and coworkers reported the total synthesis of monensin, a complex polyether natural product that acts as an ionophore. One of the key steps in this route is the late-stage union of two advanced fragments via an intermolecular aldol reaction. In this reaction, low-temperature deprotonation of the methyl ketone with lithium diisopropylamide formed the kinetic enolate which then underwent transmetalation upon the addition of magnesium bromide. Subsequent addition of the aldehyde component initiated a diastereoselective aldol reaction, forming the desired beta-hydroxyketone in 75% yield as a 3:1 mixture of diastereomers. Notably, this instance of acyclic stereocontrol is consistent with the Cram-Felkin-Anh model for the addition of nucleophiles to an aldehyde bearing an existing stereocenter in the alpha position.
Sources: en.wikipedia.org
. Whenever the integer nature of the number of agents is evident (populations with fewer than tens of thousands of individuals), inherent fluctuations in the disease spreading process caused by discrete agents result in uncertainties. In this scenario, the evolution of the disease predicted by compartmental equations deviates significantly from the observed results. These uncertainties may even cause the epidemic to end earlier than predicted by the compartmental equations. As a special case, one obtains the usual logistic function by assuming
Sandra Kazahn Masur is an American cell biologist and activist for women in academia. Masur is a professor of Ophthalmology as well as Pharmacological Sciences at Icahn School of Medicine at Mount Sinai (ISMMS) in New York City. Her research focused on membrane transport and wound healing. As a leader in promoting gender equity in science, technology, engineering, mathematics, and medicine (STEMM), Masur is the founding Director of the Office for Women's Careers at ISMMS, the Chair of the Committee on Special Awards, and Title IX Coordinator. In recognition of her commitment to developing programs that mentor all scientists, the American Society for Cell Biology named the Senior Leadership Award of the Women in Cell Biology, the Sandra K. Masur Award in her honor.
==== Gel particle synthesis ==== The synthesis of gel particles also known as hydrogels, microgels, and nanogels, has been an area of interest for researchers and industries alike for the last several decades. A microfluidic based approach to synthesizing these hydrogel particles is a useful tool, due to high throughput, mono-dispersity of particles, and cost reduction through the use of small reagent volumes. One of the key challenges early on in the field of gels was forming monodisperse particles. Initially polymerization-based techniques were used to form bulk microparticles that were polydisperse in size. These techniques generally were centered around using an aqueous solution that was mixed vigorously to create emulsions. Eventually a technique was developed to create monodisperse biodegradable microgels by making O/W emulsions in an in-line droplet generating channel geometry. This junction geometry accompanied with a surfactant laden continuous phase was responsible for creating microgels made from poly-dex-HEMA. Other device geometries including T-junction style formation are also viable and have been used to make silica-based gels. Once these methods were established, efforts focused on applying functionality to these particles. Examples include bacteria encapsulated particles, drug or protein encapsulated particles, and magnetic gel particles. To insert these functional components into the gel structure, can be as simple as integrating the component into the dispersed phase.
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.
Solid peptide is best kept frozen at about minus 20 degrees Celsius in a sealed container with desiccant. It should be allowed to reach room temperature before opening to prevent condensation. Repeated warming and cooling of the same vial is discouraged.