A practical reference on heptapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-09-30 and is reviewed periodically as new material appears.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It was derived from the ACTH(4-10) fragment, a short segment of adrenocorticotropic hormone that lacks the hormonal activity associated with the full-length peptide. Researchers at the Institute of Molecular Genetics in Moscow developed the compound during the 1980s. It has been registered as a pharmaceutical product in Russia and several neighbouring countries, where it is supplied as a nasal solution, and it is also sold internationally as a research chemical.
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.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. It is described in the literature as an analogue of the ACTH(4–10) fragment, a short N-terminal portion of adrenocorticotropic hormone that retains some neurotropic activity without the full hormonal effects of the parent peptide. The molecule carries a methionine residue at the N-terminus and two proline residues near the C-terminus, features that shape both its interactions with receptor systems and its chemical stability. The free peptide corresponds to the formula C37H51N9O10S and a molecular mass near 813.9 Da.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C37H51N9O10S | Calculated for the free peptide |
| Molar mass | 813.9 g/mol | Anhydrous free base |
| Peptide class | Synthetic heptapeptide | ACTH(4-10) analogue |
| Parent fragment | ACTH(4-10) | Adrenocorticotropic hormone segment |
| Developmental origin | Institute of Molecular Genetics, Moscow | Work began in the 1980s |
Development of the compound took place in the Soviet Union during the 1980s, largely through peptide research groups affiliated with the Shemyakin-Ovchinnikov Institute and Moscow State University. Investigators screened fragments of adrenocorticotropic hormone for activity on the central nervous system while attempting to separate cognitive effects from hormonal ones. The shortened sequence was selected because it retained behavioral activity in animal models without stimulating corticosteroid release. Early publications described the molecule as an ACTH(4-10) analog.
Published research on this peptide originates mainly from Russian laboratories, and the wider international literature is comparatively thin. Studies have used rodent models of stroke, hypoxia, and memory tasks, with a smaller number of human trials reported. Reported outcomes include changes in attention and memory measures, along with effects on neurotrophic factor expression in some experiments. Small sample sizes, inconsistent dosing protocols, and limited independent replication are widely noted limitations, so the strength of the clinical evidence remains an open question.
Semax is a synthetic heptapeptide whose sequence is Met-Glu-His-Phe-Pro-Gly-Pro. The first four residues correspond to the ACTH(4-10) fragment, while the terminal Pro-Gly-Pro extension was added to improve metabolic stability. Its molecular formula is C37H51N9O10S and its monoisotopic mass is approximately 813.9 Da. The compound is classified as a peptide research chemical and as a registered pharmaceutical product in Russia, but it does not hold marketing approval in the European Union or the United States. Naming conventions vary across supplier catalogs.
Selenium is listed as an ingredient in many multivitamins and other dietary supplements, as well as in infant formula, and is a component of the antioxidant enzymes glutathione peroxidase and thioredoxin reductase (which indirectly reduce certain oxidized molecules in animals and some plants) as well as in three deiodinase enzymes. Selenium requirements in plants differ by species, with some plants requiring relatively large amounts and others apparently not requiring any.
Maurice Loyal Huggins (September 19, 1897, Berkeley, California – December 17, 1981) was a scientist who independently conceived the idea of hydrogen bonding and who was an early advocate for their role in stabilizing protein secondary structure. An important polymer theory, Flory–Huggins theory, is also named after him.
=== United Kingdom === A Chick-fil-A operated in Edinburgh during the Spring of 2018. On October 10, 2019, Chick-fil-A returned to Europe, with the opening of a store at The Oracle shopping centre in Reading, UK. The store closed in March 2020 after The Oracle opted not to continue the lease of the location beyond the six-month pilot period in the face of continued protests over the chain's anti-LGBTQ stance. In February 2019, Chick-fil-A opened a store on a 12-month pilot scheme in Aviemore, Scotland. The store was closed in January 2020 amidst protests and controversy from locals and customers regarding the chain's former donations to charities supporting anti-LGBT rights causes. Chick-fil-A said that they had always planned a short-term stay at the location. Later, the company changed some policies, appointing its first head of diversity in 2020, and focused its charitable activities on education and hunger alleviation rather than opponents of same-sex marriage. In September 2023, the company planned to open five restaurants in the UK from early 2025, investing over $100M over the following ten years in the UK. The chain said that it would apply its charitable policies, including a $25,000 donation to a local organization on opening a Chick-fil-A restaurant and donation of surplus food to local charitable causes, to its UK branches too.
Their mission, in their words "for the purpose of mutual aid in cases of sickness, accident and death of its members or their families". In 1923 it had 8,000 members in 60 subordinate societies; that year it had a capital of over $500,000, with a further $100,000 in sick benefit funds held by local societies. All policy decisions are determined by a "Central Society" made up of the officers, founders, and representatives of the subordinate lodges. A central society meets at stated intervals to elect officers to administer the group and make needed changes. Membership is open to men 18–50, of good moral character who have passed medical exams, regardless of religious or political creeds. Germania stated that it "is not a secret society. No pass-words or grips feature its work. In fact, any man is welcome to join its meetings." German Order of Harugari Greater Beneficial Union of Pittsburgh - Incorporated April 14, 1892 in Allegheny County, Pennsylvania, as the Deutscher Unter-stuetzungs-Bund, within a month had 243 members in 6 districts. Began the periodical, Union Reporter, the next year, now known as GBU Reporter. Rituals include the candidate signing an application and the president of the local lodge giving an address about the privileges of membership and how one should enter the lodge. Union claimed to be non-sectarian and had no secrets; open to all "well-meaning persons"; non-members accompanied by members allowed at meeting.
The American Academy of Allergy, Asthma & Immunology (AAAAI); American Board of Allergy & Immunology (ABAI) International Society of Internal Medicine Internal Medicine Society of Australia and New Zealand Archived 2016-08-31 at the Wayback Machine The American Board of Internal Medicine Canadian Society of Internal Medicine The American College of Osteopathic Internists American College of Physicians
Sources: en.wikipedia.org
As mentioned above, the naturally occurring nucleotides (nucleoside-3'- or 5'-phosphates) and their phosphodiester analogs are insufficiently reactive to afford an expeditious synthetic preparation of oligonucleotides in high yields. The selectivity and the rate of the formation of internucleosidic linkages is dramatically improved by using 3'-O-(N,N-diisopropyl phosphoramidite) derivatives of nucleosides (nucleoside phosphoramidites) that serve as building blocks in phosphite triester methodology. To prevent undesired side reactions, all other functional groups present in nucleosides have to be rendered unreactive (protected) by attaching protecting groups. Upon the completion of the oligonucleotide chain assembly, all the protecting groups are removed to yield the desired oligonucleotides. Below, the protecting groups currently used in commercially available and most common nucleoside phosphoramidite building blocks are briefly reviewed:
=== Medical imaging === A physician may diagnose an inguinal hernia, as well as the type, from medical history and physical examination. For confirmation or in uncertain cases, medical ultrasonography is the first choice of imaging, because it can both detect the hernia and evaluate its changes with for example pressure, standing and Valsalva maneuver. When assessed by ultrasound or cross sectional imaging with CT or MRI, the major differential in diagnosing indirect inguinal hernias is differentiation from spermatic cord lipomas, as both can contain only fat and extend along the inguinal canal into the scrotum. On axial CT, lipomas originate inferior or lateral to the cord, and are located inside the cremaster muscle, while inguinal hernias lie anteromedial to the cord and are not intramuscular. Large lipomas may appear nearly indistinguishable as the fat engulfs anatomic boundaries, but they do not change position with coughing or straining.
Nerve endings in the vagina can provide pleasurable sensations when they are stimulated during sexual activity. Women may derive pleasure from one part of the vagina, or from a feeling of closeness and fullness during vaginal penetration. Because the vagina is not rich in nerve endings, women often do not receive sufficient sexual stimulation, or orgasm, solely from vaginal penetration. Although the literature commonly cites a greater concentration of nerve endings and therefore greater sensitivity near the vaginal entrance (the outer one-third or lower third), some scientific examinations of vaginal wall innervation indicate no single area with a greater density of nerve endings. Other research indicates that only some women have a greater density of nerve endings in the anterior vaginal wall. Because of the fewer nerve endings in the vagina, childbirth pain is significantly more tolerable. Pleasure can be derived from the vagina in a variety of ways. In addition to penile penetration, pleasure can come from masturbation, fingering, or specific sex positions (such as the missionary position or the spoons sex position). Heterosexual couples may engage in fingering as a form of foreplay to incite sexual arousal or as an accompanying act, or as a type of birth control, or to preserve virginity. Less commonly, they may use non penile-vaginal sexual acts as a primary means of sexual pleasure. In contrast, lesbians and other women who have sex with women commonly engage in fingering as a main form of sexual activity.
Radioactive isotopes that decay by pure electron capture can be inhibited from radioactive decay if they are fully ionized ("stripped" is sometimes used to describe such ions). It is hypothesized that such elements, if formed by the r-process in exploding supernovae, are ejected fully ionized and so do not undergo radioactive decay as long as they do not encounter electrons in outer space. Anomalies in elemental distributions are thought to be partly a result of this effect on electron capture. Inverse decays can also be induced by full ionisation; for instance, 163Ho decays into 163Dy by electron capture; however, a fully ionised 163Dy decays into a bound state of 163Ho by the process of bound-state β− decay. Chemical bonds can also affect the rate of electron capture to a small degree (in general, less than 1%) depending on the proximity of electrons to the nucleus. For example, in 7Be, a difference of 0.9% has been observed between half-lives in metallic and insulating environments. This relatively large effect is because beryllium is a small atom that employs valence electrons that are close to the nucleus, and also in orbitals with no orbital angular momentum. Electrons in s orbitals (regardless of shell or primary quantum number), have a probability antinode at the nucleus, and are thus far more subject to electron capture than p or d electrons, which have a probability node at the nucleus.
Sources: en.wikipedia.org
==== Wula debate ==== Another major economic problem Liu faced was the existence of the wula (corvée) system, or the forced transport labor system of the Tibetan highlands. Wula applied to services from both people and pack animals. Such compulsory work meant that many overburdened peasants either rebelled or fled the region, reducing tax revenues and hindering transportation. The scale of forced labor also resulted in serfs having no time to tend to agricultural duties. The wula system was maintained and even expanded throughout the Republican era, with authorities utilizing it as a means to collect taxes and move soldiers through the interior of the province. In addition, many Han officials and even tusi chieftains used the system for private profit and failed to pay the peasants for their labor, placing heavy burdens on local communities. Liu's first attempts to address the wula problem came in 1932 during the war with Tibet when he created the "State Wula Agency" that would purchase pack animals from local pastures. This scheme failed, although the reasons are unclear. Lawson provides several causes causes, including of a cattle disease that killed many animals and the strain of the conflict and redeployment from Tibet to Sichuan (to fight the Two-Liu War) that also caused more casualties amongst the purchased animals. The agency also suffered from major embezzlement, and it folded in 1932 after spending more than 20,000 Tibetan yuan.
== Clinical use == Regenerative medicine is the "process of replacing or regenerating human cells, tissues or organs to restore or establish normal function." Heparan sulfate analogues are one of the early examples of regenerative medicine that reached daily clinical use. Multiple articles of animal wound models demonstrated vast effects on improving wound healing heparan sulfate analogues. These findings formed a rationale for its clinical application. The first clinical studies also show a significant improvement in wound healing. Different cases have shown improvement and better wound healing over time and persistent ulcer healing after usage of heparan sulfate analogues. Even though several studies show that heparan sulfate analogues contribute to the wound healing, more research in the form of a Randomized controlled trial is needed to obtain conclusive evidence.
Textile stabilization is a conservation method for fiber and yarn-based cloth intended to mitigate damage, prevent degradation and preserve structural integrity. Stabilization is part of a broad set of techniques in the field of conservation and restoration of textiles typically undertaken by a specialist or textile conservator. Appropriate treatment is determined through risk assessment and close examination of a textile's characteristics and the nature of the damage. Organic and synthetic fibers become weak due to age, handling, and environmental exposure and display physical deterioration such as fraying, planar distortion, loss, and change in surface character. Treatment involves reinforcing tensile strength and reintegration of parts for aesthetic, functional, and historic preservation. Methods can include stitching, darning, reweaving, and the attachment of supports through overlays and underlays. Hand-sewing follows the mantra of “gently does it” using fine needles, supple yarns, and a light touch. Heavily damaged and fragile fabrics often require stabilization through adhesive consolidation, though this is less common. It is essential that conservators consider physical and chemical compatibility along with future treatability in choosing a stabilization technique.
== Bacterial short-chain fatty acids == Certain bacteria in the gastrointestinal tract ferment fecal fiber into SC-FAs and excrete them as waste products. The excreted SC-FAs enter the gastrointestinal walls, diffuse into the portal venous system, and ultimately flow into the systemic circulation. During this passage, they can activate the FFAR3 on cells in the intestinal wall as well as throughout the body. This activation may: suppress the appetite for food and thereby reduce overeating and the development of obesity; inhibit the liver's accumulation of fatty acids and thereby the development of fatty liver diseases; decrease blood pressure and thereby the development of hypertension and hypertension-related cardiac diseases; modulate insulin secretion and thereby the development and/or symptoms of type 2 diabetes; reduce heart rate and blood plasma norepinephrine levels and thereby lower total body energy expenditures; and suppress or delay the development of allergic asthma. The specific types of bacteria in the intestines can be modified to increase the number which make SC-FAs by using foods that stimulate the growth of these bacteria (i.e., prebiotics), preparations of SC-FA-producing bacteria (i.e., probiotics), or both methods (see synbiotics).
1940: Turkish archaeologist, Sumerologist, Assyriologist, and writer Muazzez İlmiye Çığ received her degree and began a multi-decade career at Museum of the Ancient Orient, one of three such institutions comprising Istanbul Archaeology Museums, as a resident specialist in the field of cuneiform tablets, thousands of which were being stored untranslated and unclassified in the facility's archives. In the intervening years, due to her efforts in the deciphering and publication of the tablets, the museum became a Middle Eastern languages learning center attended by ancient history researchers from every part of the world. 1941: American scientist Ruth Smith Lloyd became the first African-American woman to receive a PhD in anatomy. 1942: Austrian-American actress and inventor Hedy Lamarr and composer George Antheil developed a radio guidance system for Allied torpedoes that used spread spectrum and frequency hopping technology to defeat the threat of jamming by the Axis powers. Although the US Navy did not adopt the technology until the 1960s, the principles of their work are incorporated into Bluetooth technology and are similar to methods used in legacy versions of CDMA and Wi-Fi. This work led to their induction into the National Inventors Hall of Fame in 2014. 1942: American geologist Marguerite Williams became the first African-American woman to receive a PhD in geology in the United States. She completed her doctorate, entitled A History of Erosion in the Anacostia Drainage Basin, at Catholic University.
Sources: en.wikipedia.org
Semax is based on the ACTH(4-10) fragment, a seven-amino-acid segment of adrenocorticotropic hormone. The synthetic peptide retains the core sequence while removing regions associated with endocrine activity. This modification is intended to isolate effects on the nervous system.
It is registered for clinical use in Russia and a few other countries, typically as a nasal drop formulation. It does not hold approval from the United States Food and Drug Administration or the European Medicines Agency. Outside those markets it is generally handled as a research chemical.
The compound was developed in Moscow and the earliest studies were conducted there, so the primary literature is largely in Russian-language journals. Translation and indexing have been incomplete, which limits access for outside researchers. Independent groups have since published some work, but the total volume remains modest.
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.