heptapeptide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-02-27 and is reviewed periodically as new material appears.
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 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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | ~813.9 Da (free heptapeptide) | N-acetylated form is about 42 Da heavier |
| Residue count | 7 (heptapeptide) | Four residues from ACTH(4-10), three added |
| Appearance | White to off-white powder | Usually supplied lyophilized |
| Solubility class | Freely soluble in water | Also dissolves in DMSO and polar organic solvents |
| Related parent fragment | ACTH(4-10) | Parent motif is Met-Glu-His-Phe |
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.
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.
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.
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.
The substrates of the enzyme are α-ketoisovaleric acid, coenzyme A (CoA), and oxidised nicotinamide adenine dinucleotide (NAD+). Its products are isobutyryl-CoA, carbon dioxide, reduced NADH and a proton.
== Research uses == As an analog of L-phenylalanine, azidophenylalanine is incorporated into proteins during translation in place of phenylalanine. The azide group enables bioorthogonal reactions, such as copper-catalyzed or strain-promoted azide-alkyne cycloadditions, for protein modification. Azidophenylalanine is employed in metabolic labeling to detect nascent protein synthesis as a non-radioactive alternative to traditional methods. It facilitates site-specific protein labeling for microscopic imaging, purification, and FRET studies. Applications include photochemical control of fluorescent proteins, synthesis of ligands for metal complexation in EPR/NMR, and probing protein dynamics during folding or catalysis. It is incorporated using orthogonal tRNA/synthetase pairs in systems like E. coli.
==== Breast-filler toxicity ==== Biological risks to the health of a sucking infant arise from the possibility of breast-filler toxicity, that the filler-material (saline solution or silicone gel) might leak from the breast-implant into the body of the mother, then into her breast milk, and then into the infant organism; yet the biological risk to the breastfeeding infant is minimal, because silicone is indigestible and saline-solution is digestible. The study Silicone Breast Implants and Breastfeeding (1996) indicated that possible medical complications that impede breastfeeding can arise among women with silicone-filled prosthetic breasts, and found no causal relation between the presence of breast prostheses and neurological and physical impairment of the breastfeeding function of the augmented breasts.
There are two mechanisms that protect sickle cell carriers from malaria. One is that the parasite is hindered from growing and reproducing in a carrier's red blood cells; another is that a carrier's red cells show signs of damage when infected, and are detected and destroyed as they pass through the spleen.
== Dietary recommendations == According to US & Canadian Dietary Reference Intake guidelines, women ages 19–70 need to consume 46 grams of protein per day while men ages 19–70 need to consume 56 grams of protein per day to minimize risk of deficiencies. These Recommended Dietary Allowances (RDAs) were calculated based on 0.8 grams protein per kilogram body weight and average body weights of 57 kg (126 pounds) and 70 kg (154 pounds), respectively. However, this recommendation is based on structural requirements only and disregards use of protein for energy metabolism. This requirement is for a normal sedentary person. In the United States, average protein consumption is higher than the RDA. According to results of the National Health and Nutrition Examination Survey (NHANES 2013–2014), average protein consumption for women ages 20 and older was 69.8 grams and for men 98.3 grams/day. According to research from Harvard University, the National Academy of Medicine suggests that adults should consume at least 0.8 grams of protein per kilogram of body weight daily, which is roughly equivalent to a little more than 7 grams for every 20 pounds of body weight. This recommendation is widely accepted by health professionals as a guideline for maintaining muscle mass, supporting metabolic functions, and promoting overall health.
Sources: en.wikipedia.org
the area of contact was larger than that predicted by Hertz theory, the area of contact had a non-zero value even when the load was removed, and there was even strong adhesion if the contacting surfaces were clean and dry. This indicated that adhesive forces were at work. The Johnson-Kendall-Roberts (JKR) model and the Derjaguin-Muller-Toporov (DMT) models were the first to incorporate adhesion into Hertzian contact.
=== Terminal deoxynucleotidyl transferase === Thymosin β4 induces the activity of the enzyme terminal deoxynucleotidyl transferase in populations of thymocytes (thymus-derived lymphocytes). This suggests that the peptide may contribute to the maturation of these cells.
"Cid", "Lucy", "Sidney", "Blotters", "Droppers", "Sugar Cubes") O-Acetylpsilocin (believed to be a prodrug of psilocin) psilocin (found in psilocybin mushrooms) psilocybin (also found in psilocybin mushrooms; prodrug to psilocin) ibogaine (found in Tabernanthe iboga ("Iboga")) Atypicals salvinorin A (found in Salvia divinorum, a trans-neoclerodane diterpenoid ("Diviner's Sage", "Lady Salvia", "Salvinorin")) tetrahydrocannabinol (found in cannabis)
This bonding mode is observed in the commonly available metal carbonyls: Co2(CO)8, Fe2(CO)9, Fe3(CO)12, and Co4(CO)12. In certain higher nuclearity clusters, CO bridges between three or even four metals. These ligands are denoted μ3-CO and μ4-CO. Less common are bonding modes in which both C and O bond to the metal, such as μ3η2.
Sources: en.wikipedia.org
The sequence is Met-Glu-His-Phe-Pro-Gly-Pro, a seven-residue peptide. The first four residues correspond to the ACTH(4-10) fragment, and Pro-Gly-Pro is added at the C-terminus. N-acetylated versions also appear in the literature and differ in mass.
Semax is a synthetic analog of the ACTH(4-10) fragment rather than a copy of the full hormone. Truncation plus the added tail removes the steroidogenic portion of ACTH. That distinction explains why it is studied for nervous-system effects instead of adrenal stimulation.
It is registered as a prescription product in Russia and has been used there clinically, chiefly by the intranasal route. No approval exists in the United States or the European Union. Availability elsewhere typically falls under research-chemical distribution, with varying purity documentation.
It is registered as a pharmaceutical product in Russia, where it is typically supplied as a nasal solution. In most other countries it is not an approved drug and is traded as a research chemical instead. Approval status depends entirely on the jurisdiction involved.