A practical reference on melanocortin signalling: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-11 and is reviewed periodically as new material appears.
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.
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.
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.
| 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.
Regulatory status varies sharply by country. Semax is registered for medical use in Russia, where it appears in formularies as a nasal solution, and it also holds registration in a small number of neighbouring states. It has no approval from the United States Food and Drug Administration or the European Medicines Agency, and it is not a scheduled controlled substance in most jurisdictions. Elsewhere it circulates mainly as laboratory material, so purity documentation comes from suppliers rather than from a national pharmacopoeia.
Semax is a synthetic peptide created in the Soviet Union during the early 1980s by researchers working in Moscow. It was built from the short adrenocorticotropic hormone fragment known as ACTH(4-10), and the chain was then extended with three additional amino acids. The resulting molecule was named semax and entered clinical use in Russia in 1994. It is generally described as a nootropic and neuroprotective agent rather than as a hormone analogue.
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.
To what extent suicidal thoughts are influenced by behavioral symptoms is unclear, as they signify a desire to avoid the later stages of the disease. Suicide is the greatest risk of this disease before the diagnosis is made and in the middle stages of development throughout the disease. Other associated risks include choking due to the inability to swallow, physical injury from falls, and malnutrition.
Some cases of chronic intracranial hypotension due to CSF leak may present as personality changes, altered behaviors and impairment of executive functions, similar to behavioral-variant frontotemporal dementia as the frontal and temporal lobes are affected by downward sagging due to reduced intra-cranial pressures. An untreated CSF leak can result in coma or death as late stage findings as the brainstem herniates through the skull base or foramen magnum.
==== Adsorption ==== Adsorption is a mass transfer process in which a substance is transported from the liquid phase to the surface of a solid/liquid (adsorbent) and becomes physically and chemically bonded (adsorbate). Adsorption can be classified into two forms based on the type of attraction between the adsorbate and the adsorbent: physical and chemical adsorption, commonly known as physisorption and chemisorptions.
=== Diplomats === Hamzat Ahmadu - Nigerian diplomat, former ambassador to the Soviet Union, the United States of America and high commissioner to the Bahamas. Nuhu Bamalli - Former minister of foreign affairs Mohammed Sanusi Barkindo – 28th Secretary-General of OPEC. Ibrahim Gambari – (Fulani/Yoruba); Scholar and diplomat; Chief of Staff to the president; Under-Secretary-General / Special Adviser – Africa United Nations; former minister of foreign affairs, current chief of staff to the president of Nigeria. Amina J. Mohammed – (Fulani/English); Politician; Deputy Secretary-General of the United Nations; former Federal Minister of Environment, Nigeria. Tijjani Muhammad-Bande – Political scientist, administrator and career diplomat. Current president of the United Nations General Assembly, Permanent Representative of Nigeria to the UN, former VP of the UN General Assembly. Nura Abba Rimi - Nigeria's ambassador to the Arab Republic of Egypt, with concurrent accreditation to the State of Palestine and the State of Eritrea; former Presidential Liaison Officer. Ibrahim Sulu-Gambari – (Fulani/Yoruba); Nigerian judge and monarch. Current Emir of Ilorin, Nigeria. Yusuf Tuggar – Minister of Foreign Affairs. Aminu Bashir Wali - Former permanent representative to the United Nations, former minister of foreign affairs. Isa Wali - former Nigerian high commissioner to Ghana.
== History == The journal was established in 1963 as Clinical Chemistry/Klinische Chemie. In 1991 it was renamed to European Journal of Clinical Chemistry and Clinical Biochemistry. In 1998 it obtained its present name.
Sources: en.wikipedia.org
=== α1-Adrenergic receptor antagonism === Some beta blockers (e.g., labetalol and carvedilol) exhibit mixed antagonism of both β- and α1-adrenergic receptors, which provides additional arteriolar vasodilating action.
=== United States === Under the Controlled Substances Act, dihydromorphine is listed as a Schedule I substance along with heroin. In the United States, its role in the production of dihydrocodeine and other related drugs make it a Schedule I substance with one of the higher annual manufacturing quotas granted by the US Drug Enforcement Administration: 3300 kilograms in 2013. Manufacturers, distributors, and importers with the correct DEA license and state permits related thereto are able to use Schedule I drugs in this fashion when they are transformed into something of a lower schedule. The DEA has assigned dihydromorphine and all of its salts, esters, etc. the ACSCN of 9145. As with nicomorphine, MDMA and heroin, dihydromorphine is also used in research in properly licensed facilities. US DEA Form 225, the most common and least expensive individual researcher's license, does not include Schedule I drugs, and so the lab must have a higher-level DEA registration. As with other licit opioids used for medical purposes in other countries, including even much weaker opioids like nicocodeine, benzylmorphine, and tilidine, the reason for dihydromorphine being in Schedule I is that it was not in medical use in the US at time the Controlled Substances Act of 1970 was drawn up.
== History == 1993-2000 In 1994, Hetero began operating their first API manufacturing unit in Hyderabad, and by 1995 Hetero formalized its commitment to scientific research with the establishment of the Hetero Research Foundation (HRF). HRF is a dedicated research institution that serves as the engine of the company’s new medicine development and molecule work. By 1997, four years after its founding, Hetero emerged as one of the leading companies globally offering affordable antiretroviral APIs, having independently developed generic processes for more than 20 molecules. This placed Hetero at the forefront of the global effort to improve access to HIV/AIDS treatment in low income countries at a time when branded ARVs were incredibly expensive for the majority of patients. 2001-2005 Three years later, in 2001, Hetero received its first USFDA approval for an API facility in Hyderabad, marking the company’s formal entry into regulatory environments and laying the foundation for its subsequent US businesses. By 2005, Hetero broadened its capabilities beyond antiretrovirals and gained recognition as one of the first companies in India to develop and market the antiviral medication Oseltamivir, for the treatment of bird flu and swine flu. 2006-2009 In 2006, Hetero received USFDA approval for a finished dosage manufacturing facility in Hyderabad, an important development that enabled the company to supply generic formulations directly to the US market. This marked Hetero’s vertical integration from raw material production to patient ready medicines.
Metal toxicity or metal poisoning is toxicity affecting plants, animals, or humans due to excessive concentration of metals. At low concentrations, metals such as copper, iron, manganese, and zinc are essential nutrients obtained through the diet supporting health, but have toxicity at high exposure concentrations. Other metals having no biological roles in animals, but with potential for toxicity include arsenic, cadmium, lead, mercury, and thallium. Exposure to metals, primarily due to occupational exposure or environmental pollution, can increase metal concentration into hazardous range. Some metals are toxic when they form poisonous soluble compounds which interfere with enzyme systems, such as superoxide dismutase, catalase, or glutathione peroxidase. Only soluble metal-containing compounds are toxic by forming coordination complexes, which consist of a metal ion surrounded by ligands. Ligands can range from water in metal aquo complexes to alkyl groups, as in tetraethyl lead. Toxic metal complexes can be detoxified by conversion to insoluble derivatives or by binding them in rigid molecular environments using chelating agents. An option for treatment of metal poisoning may be chelation therapy, which involves the administration of chelation agents to remove metals from the body.
Sources: en.wikipedia.org
Bacitracin is a polypeptide antibiotic. It is a mixture of related cyclic peptides produced by Bacillus licheniformis bacteria, that was first isolated from the variety "Tracy I" (ATCC 10716) in 1945. These peptides disrupt Gram-positive bacteria by interfering with cell wall and peptidoglycan synthesis. Bacitracin is primarily used as a topical preparation, as it can cause kidney damage when used internally. It is generally safe when used topically, but in rare cases may cause hypersensitivity, allergic or anaphylactic reactions, especially in people allergic to neomycin. In 2023, it was the 323rd most commonly prescribed medication in the United States, with more than 100,000 prescriptions.
Since 2018, with the federal government's passing of the SUPPORT (Substance Use-Disorder Prevention That Promotes Opioid Recovery and Treatment for Patients and Communities Act) Act, federal restrictions on methadone use for patients receiving Medicare have been lifted. Since March 2020, as a result of the COVID-19 pandemic, buprenorphine may be dispensed via telemedicine in the U.S. In October 2021, New York Governor Kathy Hochul signed legislation to combat the opioid crisis. This included establishing a program for the use of medication-assisted substance use disorder treatment for incarcerated individuals in state and local correctional facilities, decriminalizing the possession and sale of hypodermic needles and syringes, establishing an online directory for distributors of opioid antagonists, and expanding the number of eligible crimes committed by individuals with a substance use disorder that may be considered for diversion to a substance use treatment program. Until these laws were signed, incarcerated New Yorkers did not reliably have access to medication-assisted treatment. Syringe possession was still a class A misdemeanor despite New York authorizing and funding syringe exchange and access programs. This legislation acknowledges the ways New York State laws have contributed to opioid deaths: in 2020 more than 5,112 people died from overdoses in New York State, with 2,192 deaths in New York City.
=== Pharmacodynamics === Aticaprant is a potent, selective, short-acting (i.e., non-"inactivating") antagonist of the KOR (Ki = 0.81 nM vs. 24.0 nM and 155 nM for the μ-opioid receptor (MOR) and δ-opioid receptor (DOR), respectively; approximately 30-fold selectivity for the KOR). The drug has been found to dose-dependently block fentanyl-induced miosis at 25 mg and 60 mg in humans (with minimal to no blockade at doses of 4 to 10 mg), suggesting that the drug significantly occupies and antagonizes the MOR at a dose of at least 25 mg but not of 10 mg or less. However, a more recent study assessing neuroendocrine effects of the drug in normal volunteers and subjects with a history of cocaine dependence reported observations consistent with modest MOR antagonism at the 10 mg dose. In animal models of depression, aticaprant has been found to have potent synergistic efficacy in combination with other antidepressants such as citalopram and imipramine. Positron emission tomography imaging revealed that brain KORs were almost completely saturated by the drug 2.5 hours following a single dose of 10 mg, which supported the 4 mg to 25 mg dosages that aticaprant is being explored at in clinical trials. Occupancy was 35% for a 0.5 mg dose and 94% for a 10 mg dose. At 24 hours post-dose, receptor occupancy was 19% for 0.5 mg and 82% for 25 mg. No serious side effects were observed, and all side effects seen were mild to moderate and were not thought to be due to aticaprant.
For weight loss to be permanent, changes in diet and lifestyle must be permanent as well. There is evidence that counseling or exercise alone do not result in weight loss, whereas dieting alone results in meaningful long-term weight loss, and a combination of dieting and exercise provides the best results. Meal replacements, orlistat, a very-low-calorie diet, and primary care intensive medical interventions can also support meaningful weight loss.
=== Environmental pollution === When metal toxicity in the environment is suspected, pathologies in fish, clams, birds, insects, and vegetation may serve as signals for contamination and toxicities. Physiological mechanisms of metal toxicity may have a spectrum of effects, ranging from changes in behavior and symptoms of illness, to death of small animal species. Toxic metal particles in ecosystems may remain for hundreds or even thousands of years, with potentially millions of people exposed to high concentrations at some point in their lives. Commonly, there is no visible evidence of metals pollution in soil or water. The geographical extent of sources may be very large. For example, up to one-sixth of China's arable land might be affected by heavy metal contamination.
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 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.