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 2026-04-11 and is reviewed periodically as new material appears.
Development took place during the 1980s at institutes of the Russian Academy of Sciences, where peptide fragments of ACTH were screened for cognitive and neuroprotective effects. The compound received regulatory approval in Russia as a nasal preparation, marketed for conditions such as ischemic stroke, transient ischemic attacks, and optic nerve disorders. Registration in other countries has not followed. Most published clinical reports originate from a small number of Russian research groups, and independent replication outside that setting remains limited. The regulatory status therefore differs sharply between Russia and the rest of the world.
Laboratory work points toward modulation of neurotrophic signaling, particularly expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal tissue. Studies also describe effects on monoamine turnover, inflammatory mediators, and oxidative markers. These observations come mainly from animal models and cultured cells, so the causal chain in humans is not firmly established. Whether the reported molecular changes translate into measurable clinical benefit is an open question. Reviews generally present the mechanism as plausible rather than demonstrated.
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.
| Property | Value | Notes |
|---|---|---|
| Sequence | Met-Glu-His-Phe-Pro-Gly-Pro | Heptapeptide; ACTH(4-10) analog extended at C-terminus |
| Molecular mass | ~813.9 Da | Free peptide, unmodified |
| Appearance | White to off-white powder | Typical lyophilized solid |
| Solubility | Soluble in water and saline | Also soluble in common aqueous buffers |
| Storage (solid) | -20 °C, desiccated | Protect from moisture and repeated thawing |
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.
The C-terminal Pro-Gly-Pro extension is not incidental. Proline-rich tails are known to resist several common peptidases, and the published literature attributes the longer half-life of Semax, relative to unmodified ACTH fragments, to this feature. The modification also removes the melanocyte-stimulating and corticosteroidogenic activity that characterizes longer ACTH-derived sequences. Because the molecule is small and hydrophilic, it is typically formulated as an aqueous solution for intranasal or parenteral delivery. Acetylation or amidation at the termini appears in closely related research peptides and shifts the mass by a fixed increment.
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.
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There is much criticism indicating that the Nova classification refers to formulation and additives while processing levels must relate to unit operations and food processing. Food processing categories with typical processes are given in Table 1.
=== Degradation of insulin === Once an insulin molecule has docked onto the receptor and effected its action, it may be released back into the extracellular environment or it may be degraded by the cell. Degradation normally involves endocytosis of the insulin-receptor complex followed by the action of insulin degrading enzyme. Most insulin molecules are degraded by liver cells. It has been estimated that a typical insulin molecule is finally degraded about 71 minutes after its initial release into circulation.
A typical teleost fish has a streamlined body for rapid swimming, and locomotion is generally provided by a lateral undulation of the hindmost part of the trunk and the tail, propelling the fish through the water. There are many exceptions to this method of locomotion, especially where speed is not the main objective; among rocks and on coral reefs, slow swimming with great manoeuvrability may be a desirable attribute. Eels locomote by wiggling their entire bodies. Living among seagrasses and algae, the seahorse adopts an upright posture and moves by fluttering its pectoral fins, and the closely related pipefish moves by rippling its elongated dorsal fin. Gobies "hop" along the substrate, propping themselves up and propelling themselves with their pectoral fins. Mudskippers move in much the same way on terrestrial ground. In some species, a pelvic sucker allows them to climb, and the Hawaiian freshwater goby climbs waterfalls while migrating. Gurnards have three pairs of free rays on their pectoral fins which have a sensory function but on which they can walk along the substrate. Flying fish launch themselves into the air and can glide on their enlarged pectoral fins for hundreds of metres.
Sources: en.wikipedia.org
Much of his work, especially of the enzymes on aldolase and transaldolase was done in collaboration with Sandro Pontremoli at the University of Genoa. Horecker published many papers, of which Web of Science lists 450, many of them highly cited. The breadth of his work can be judged from papers on a wide variety of topics, such as galactose oxidase, metabolic formation of phosphglycerate, protein kinase-C, release of alkaline phosphatase from bacterial cells and prothymosin-α.
== Outcome == Seborrhoeic dermatitis is generally a chronic and recurring condition. Individuals may have the condition for several weeks to months, but it may also last years or their lifetime. There may be periods of relapse and worsening.
Also in attendance was Nikita Khrushchev of the Soviet Union. July 27: Austria becomes an independent country after the end of the Allied occupation. The last allied troops leave the country in October. August 15: The First Sudanese Civil War begins between the north and the south. November 1: MAAG Vietnam is organized, often regarded as the starting point of the Vietnam War.
People with early keratoconus often notice a minor blurring or distortion of their vision, as well as an increased sensitivity to light, so they may visit their clinician seeking corrective lenses for reading or driving. At early stages, the symptoms of keratoconus may be no different from those of any other refractive defect of the eye. As the disease progresses, vision deteriorates, sometimes rapidly due to irregular astigmatism. Visual acuity becomes impaired at all distances, and night vision is often poor. Some individuals have vision in one eye that is markedly worse than the other eye. The disease is often bilateral though asymmetrical. Some develop photophobia (sensitivity to bright light), eye strain from squinting in order to read, or itching in the eye, but there is normally little or no sensation of pain. It may cause luminous objects to appear as cylindrical pipes with the same intensity at all points.
== Sources == Cole, R D (1996), "Choh Hao Li: April 21, 1913 - November 28, 1987", Biographical Memoirs of the National Academy of Sciences, vol. 70, pp. 221–39, PMID 11619324 Hruby, Victor J.; Yamashiro, Donald (1988), "Memorial issue in honor of Professor Choh Hao Li. Part I", Int. J. Pept. Protein Res, vol. 32, no. 6 (published Dec 1988), pp. 417–598, doi:10.1111/j.1399-3011.1988.tb01371.x, PMID 3073145 Hruby, V J (1988), "In memoriam Choh Hao Li, April 21, 1913-November 28, 1987", Int. J. Pept. Protein Res, vol. 31, no. 3 (published Mar 1988), pp. 253–4, PMID 3286549 "Classic pages in Obstetrics and Gynecology. Interstitial cell stimulating hormone. II. Method of preparation and some physico-chemical studies, by Choh Hao Li, Miriam E. Simpson, and Herbert M. Evans. Endocrinology, vol. 27, pp. 803–808, 1940", Am. J. Obstet. Gynecol, vol. 17, no. 5 (published Nov 1, 1973), p. 716, 1973, PMID 4599575 "Choh Hao Li", Triangle; the Sandoz Journal of Medical Science, vol. 9, no. 1, pp. 41–2, 1969, ISSN 0041-2597, PMID 4896971 Ingle, D J; Nezamis, J E; Moreley, E H; Li, C H (1953), "The effect of some partially purified preparations of corticotrophin upon the work performance of adrenalectomized-hypophysectomized rats", Acta Endocrinol, vol. 14, no. 2 (published Oct 1953), pp. 93–8, doi:10.1530/acta.0.0140093, PMID 13113828
Sources: en.wikipedia.org
Semax is a synthetic seven-amino-acid peptide derived from a fragment of corticotropin. It is used in Russia as a nasal preparation, while elsewhere it is studied as a research compound. It is not approved as a medicine in most countries.
Its sequence corresponds to the 4-10 region of corticotropin extended by three residues. This fragment lacks the region responsible for adrenal steroid release, so it is explored for neural rather than hormonal effects. The relationship explains the compound's classification among ACTH-derived peptides.
It holds approval in Russia for several neurological indications as a nasal spray or drop formulation. Regulatory agencies in the United States and the European Union have not approved it. Products sold elsewhere are generally labeled for research use only.
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.