heptapeptide 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.
Updated 2025-11-10. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 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.
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.
| 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 |
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.
Semax is a synthetic heptapeptide developed in the Soviet Union during the 1980s by researchers at the Institute of Molecular Genetics in Moscow. It was designed as a truncated analog of adrenocorticotropic hormone, retaining only the fragment spanning residues four through ten. Investigators sought a peptide that would preserve the cognitive effects associated with ACTH while eliminating the hormonal stimulation of the adrenal cortex. The compound entered clinical use in Russia during the following decade.
Semax is a synthetic heptapeptide with the sequence Met-Glu-His-Phe-Pro-Gly-Pro. Its chain combines the first seven residues of corticotropin with a C-terminal proline-glycine-proline extension, a modification intended to slow enzymatic breakdown. The free peptide has a molecular mass near 813.9 daltons. It belongs to the class of ACTH-derived fragments studied for central nervous system activity rather than for adrenal steroid stimulation. This structural relationship to a natural hormone fragment is the usual starting point for describing the compound in the literature.
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.
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.
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.
=== Hair growth === Dermal macrophages are the essential component of the hair follicle immune system. They generally facilitate hair growth. There are three steps of hair growth: anagen, catagen, and telogen. During catagen, dermal macrophages' population decreases progressively when the hair grows. The number of dermal macrophages in hair follicles reaches a minimum during telogen (resting state) and increases during anagen (beginning of another growth cycle). In rodents, perifollicular macrophages can actively remove collagen fibres around the follicles via phagocytosis. This phenomenon might contribute to remodelling the follicular composition during anagen when dermal macrophages prevent the activation of follicular stem cells, thereby preventing entry to catagen, a process in which hair stops growing. Hence, dermal macrophages facilitate the growth of the hair by preventing the halt of the growth process and its regression. When under physical stress, the release of CCL2 (cytokine) in the hair follicle induces the infiltration of macrophages. The infiltrated macrophages mainly express an M1 phenotype, which are pro-inflammatory macrophages that could trigger apoptosis of cells in the follicle by their upregulation of pro-inflammatory cytokines such as TNF-a. However, TNF-a is a major factor facilitating hair regeneration by promoting various pathways' signalling (Wnt, NF-κB pathway). Dermal macrophages could also contribute to hair regeneration by skewing towards the anti-inflammatory phenotype (M2) under minor stress.
Electromagnetic radiation travels, when unobstructed, at the speed of light, the defined value 299,792,458 m/s in SI units. The superposition principle is always exactly true. For example, the electric potential generated by two charges is the simple addition of the potentials generated by each charge in isolation. The value of the electric field at any point around these two charges is found by calculating the vector sum of the two electric fields from each of the charges acting alone. The permittivity and permeability are exactly the electric constant ε0 and magnetic constant μ0, respectively (in SI units), or exactly 1 (in Gaussian units). The characteristic impedance (η) equals the impedance of free space Z0 ≈ 376.73 Ω. The vacuum of classical electromagnetism can be viewed as an idealized electromagnetic medium with the constitutive relations in SI units:
==== Blood stains ==== There are several reddish stains on the shroud suggesting blood. McCrone (see painting hypothesis) showed that these contain iron oxide, and theorized that its presence was likely due to simple pigment materials used in medieval times. While the forensic doctor Pierluigi Baima Bollone initially claimed in 1983 to have identified type AB human blood along with traces of serum, aloes, and myrrh, this conclusion was later challenged by researchers like Alan Adler and more recently Kelly Kearse, who noted that early testing methods could not definitively confirm ancient human blood due to degradation and potential contamination. Skeptics cite forensic blood tests whose results dispute the authenticity of the Shroud, and point to the possibility that the blood could belong to a person who handled the shroud, and that the apparent blood flows on the shroud are unrealistically neat. As of 2025, it has not been scientifically demonstrated that the blood is of human, or even primate, origin.
== In popular culture == The 1896 Gilbert and Sullivan operetta The Grand Duke features sausage rolls as a plot device, where conspirators recognise one another by eating sausage rolls. From 2018 to 2022, English YouTuber LadBaby had five consecutive Christmas number ones on the UK Singles Chart with cover versions of songs where the lyrics were rewritten to reference sausage rolls, including "I Love Sausage Rolls", "Don't Stop Me Eatin'", and "Sausage Rolls for Everyone".
Sources: en.wikipedia.org
== Research potential == GHRH naturally declines with age. No conclusive results are known whether sermorelin could yield potential benefits for adults, such as to enhance pituitary function or mimic growth hormone secretion patterns. Orally active growth hormone-releasing peptides may be under development. Sermorelin may be an alternative to rhGH for growth hormone replacement therapy (GHRT) in aging adults. Sermorelin can be prescribed for off-label use without the legal restrictions that apply to rhGH.
(123Te is expected to decay to 123Sb, but the half-life appears to be so long that the decay has never been observed.) There are no stable nuclides having atomic number greater than Z = 82 (lead), although bismuth (Z = 83) is stable for all practical human purposes, and thorium (Z = 90) and uranium (Z = 92) are sufficiently long-lived to occur on Earth in large quantities. Elements with atomic numbers from 1 to 82 all have stable isotopes, with the exceptions of technetium (Z = 43) and promethium (Z = 61).
=== Janata Party and Bharatiya Janata Party === After the Emergency was lifted, he was elected to the 6th Lok Sabha (1977–1979) on a Janata Party ticket from Kapadvanj but lost that seat in 1980 elections. He was the Vice-President of the Janata Party in Gujarat and from 1980 to 1991 he was the General Secretary and President of the Bharatiya Janata Party (BJP) in Gujarat. He was a member of the Rajya Sabha from 1984 to 1989. In 1989 he was elected to the 9th Lok Sabha (1989–91) from Gandhinagar and in 1991 he was re-elected to the 10th Lok Sabha (1991–96) from Godhra (Lok Sabha constituency). In 1995, BJP won a majority of 121 seats in the 182-member Legislative Assembly. Many party legislators expressed a preference for Vaghela as their leader. However, the BJP leadership installed Keshubhai Patel as the Chief Minister, and the support for Vaghela was gradually eroded. Narendra Modi is said to have thrown his weight behind Keshubhai Patel in preference to Vaghela, and was held responsible for the ensuing events by Vaghela. In September 1995, Vaghela rebelled against the BJP leadership with the support of 47 MLAs. In the subsequent compromise worked out by the leadership, Keshubhai Patel was replaced by a Vaghela loyalist Suresh Mehta as the Chief Minister. Modi was temporarily banished from Gujarat. Vaghela lost Godhra seat in May 1996 Lok Sabha polls, and soon left Bharatiya Janata Party with his supporters, bringing down Suresh Mehta's government.
By contrast, K-selected species display traits associated with living at densities close to carrying capacity, and typically are strong competitors in such crowded niches that invest more heavily in fewer offspring, each of which has a relatively high probability of surviving to adulthood (i.e., low r, high K). Between these two extremes, the American kestrel is one of the few raptor species that lean towards being r-selected. They are able to breed at one year old, have few non-breeding adults in the population, and have larger broods. Their population growth rate is high relative to larger raptors, which typically lean towards being K-selected. This said, older American kestrel pairs generally have larger brood sizes and produce more viable offspring than younger conspecifics.
The first symptoms of apitoxin (bee venom), that are now thought to be caused by apamin, were described back in 1936 by Hahn and Leditschke. Apamin was first isolated by Habermann in 1965 from Apis mellifera, the Western honey bee. Apamin was named after this bee. Bee venom contains many other compounds, like histamine, phospholipase A2, hyaluronidase, MCD peptide, and the main active component melittin. Apamin was separated from the other compounds by gel filtration and ion exchange chromatography.
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.
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.