melanocortin receptor comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-09-08. Where a claim depends on a specific study, the study is described rather than over-claimed.
Pharmacologically, melanotan-2 behaves as a non-selective agonist across the melanocortin receptor family. Binding at MC1R on dermal melanocytes promotes eumelanin synthesis, which underlies the tanning response described in early human work. Activity at the centrally expressed MC4R receptor is associated with reported effects on appetite and erectile function. Because the peptide does not discriminate strongly among receptor subtypes, attributing any single observed effect to one receptor pathway is generally not possible without selective antagonists or receptor knockout models.
Research interest has centred on photoprotection and pigmentation, with a smaller body of work on appetite and sexual function. Published human data remain limited to small, frequently uncontrolled studies, and the compound has never received marketing approval from a national medicines regulator. Most laboratory work treats it as a pharmacological tool for probing melanocortin signalling in cell culture or animal models. Whether pigmentation changes observed in people translate into measurable protection against ultraviolet-induced DNA damage remains an open question.
Published pharmacokinetic information is limited and comes mainly from small studies rather than registrational trials. Plasma half-life is usually described as short, on the order of tens of minutes, followed by rapid tissue distribution and clearance of the intact peptide. Metabolites and low concentrations of parent compound have been reported in urine, a detail relevant to anti-doping and forensic testing. Whether repeated exposure changes receptor sensitivity or clearance over time remains an open question. Values differ noticeably between analytical assays, so published numbers should be read as approximate rather than definitive.
Melanotan II is a synthetic cyclic heptapeptide with the sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, corresponding to a molecular formula of C50H69N15O9 and a monoisotopic mass near 1024 daltons. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, a peptide hormone produced by cleavage of proopiomelanocortin. A lactam bridge between the aspartate and lysine side chains closes the ring, and the C-terminal amide removes a free carboxyl group. Both modifications increase resistance to enzymatic degradation compared with the linear parent hormone. Four substitutions distinguish it from afamelanotide, the linear analogue studied under the name melanotan I.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | Melanotan II; MT-II; N-acetyl-norleucyl-cyclo[Asp-His-D-Phe-Arg-Trp-Lys] amide | Naming follows peptide convention; the numeral distinguishes it from melanotan-1 |
| Molecular formula | C50H69N15O9 | Includes the lactam bridge; no counter-ion assumed |
| Monoisotopic mass | 1023.53 Da | Free base; salts and counter-ions shift the observed value |
| Appearance | White to off-white lyophilised powder | Batch-to-batch colour variation is not itself proof of impurity |
| Typical analytical method | RP-HPLC purity determination with ESI-MS identity confirmation | Retention time alone does not establish sequence identity |
Exposure to siliceous dusts in the ceramics industry is reduced by either processing and using the source materials as aqueous suspension or as damp solids, or by the use of dust control measures such as local exhaust ventilation. These have been mandated by legislation, such as The Pottery (Health and Welfare) Special Regulations 1950. The Health and Safety Executive in the UK has produced guidelines on controlling exposure to respirable crystalline silica in potteries, and the British Ceramics Federation provide, as a free download, a guidance booklet. Archived 2023-04-19 at the Wayback Machine
The elaboration of a method for the reduction of aromatic rings to the corresponding dihydrobenzenes under controlled conditions by A. J. Birch opened a convenient route to compounds related to the putative 19-norprogesterone. This reaction, now known as the Birch reduction, is typified by the treatment of the monomethyl ether of estradiol (1) with a solution of lithium metal in liquid ammonia in the presence of alcohol as a proton source. Initial reaction constituents of 1,4-dimetalation of the most electron deficient positions of the aromatic ring–in the case of an estrogen, the 1 and 4-positions. Rxn of the intermediate with the proton source leads to a dihydrobenzene; a special virtue of this sequence in steroids is the fact that the double bond at 2 is in effect becomes an enol ether moiety. Treatment of this product, 1,4-Dihydroestradiol 3-methyl ether [1091-93-6] (2), with weak acid, e.g. oxalic acid, leads to the hydrolysis of the enol ether, producing β,γ-unconjugated ketone Prenortestosterone [1089-78-7] (3). Hydrolysis under more strenuous conditions (mineral acids) results in migration/conjugation of the olefin to yield nandrolone (4). The Prenortestosterone [1089-78-7] is also of interest to us because it has use in the synthesis of Dienolone. Birch reduction of estrone methyl ether will work. Back-oxidation of the 17beta-hydroxy group will give Bolandione (cmp 14). Reduction of the 3-keto group in nandrolone (lithium aluminium hydride was given in patent) will give bolandiol.
Cotadutide is an experimental drug for the treatment of type 2 diabetes mellitus. It lowers blood glucose levels by mimicking the human hormones glucagon-like peptide 1 and glucagon, which play a role in blood sugar regulation. The drug is a peptide that is injected under the skin. Cotadutide is in Phase II clinical trials as of February 2021. Cotadutide, a therapeutic agent, was undergoing Phase II clinical trials. This stage of trials typically involves evaluating the drug's effectiveness and further assessing its safety in a larger group of participants, compared to earlier phases.
glycolysis The metabolic pathway in which carbohydrate sugars such as glucose are broken down into simpler molecules, releasing chemical energy which can then be used for various cellular functions. In a series of ten enzyme-catalyzed reactions, each molecule of glucose is converted into two molecules of pyruvate, with the free energy liberated in this process simultaneously being used to form high-energy bonds in two molecules of reduced nicotinamide adenine dinucleotide (NADH) and two molecules of adenosine triphosphate (ATP). In aerobic conditions pyruvate and NADH are further oxidized in the mitochondria; in anaerobic conditions NADH itself subsequently reduces pyruvate to lactate.
The [pharmaceutical] industry has taken advantage of the incentives to charge excessive profits and to reap windfalls far in excess of their investments in the drug. Provigil was an orphan drug and went on to be a blockbuster.
Sources: en.wikipedia.org
Clinical and Vaccine Immunology (CVI) was a peer-reviewed journal published by the American Society for Microbiology. CVI enhances our understanding of the immune response in health and disease by showcasing important clinically relevant research, including new animal models for human immunologic diseases, viral immunology, immunopathogenesis, and clinical laboratory immunology. In particular, the journal highlights important discoveries in immunization and vaccine research, such as the development and evaluation of vaccines, human and animal immune responses to vaccines, vaccine vectors, adjuvants and immunomodulators, quantitative assays of vaccine efficacy, and clinical trials. The journal publishes primary research articles, editorials, commentaries, minireviews, and case reports. Articles are freely accessible after six months (delayed open access). Through its "Global Outreach Program", free online access is available to qualified microbiologists in eligible developing countries.
== Symbols and units == The IUPAC-recommended symbols for mass and charge are m and Q, respectively, however using a lowercase q for charge is also very common. Charge is a scalar property, meaning that it can be either positive (+) or negative (−). The Coulomb (C) is the SI unit of charge; however, other units can be used, such as expressing charge in terms of the elementary charge (e). The SI unit of the physical quantity m/Q is kilogram per coulomb.
=== Non-medical use === Combining a muscle relaxant like carisoprodol with opioids and benzodiazepines is known as "The Holy Trinity" as it has been reported to increase the power of the "high". Recreational users of carisoprodol usually seek its potentially heavy sedating, relaxant, and anxiolytic effects. Because of its potentiating effects on narcotics, it is often used in conjunction with opioids. Carisoprodol is not tested for on standard drug testing screens, although tests for it do exist. On 26 March 2010 the DEA issued a Notice of Hearing on a proposal for placing carisoprodol in schedule IV of the Controlled Substances Act, later confirming its classification under schedule IV. Carisoprodol is sometimes mixed with date rape drugs.
=== Political changes === The revolution brought Romania vast attention from the outside world. Initially, much of the world's sympathy went to the FSN government under Ion Iliescu, a former member of the CPR leadership and a Ceaușescu ally prior to falling into the dictator's disfavour in the early 1980s. The FSN, composed mainly of former members of the second echelon of the CPR, immediately assumed control over the state institutions, including the main media outlets such as the national radio and television networks. They used their control of the media to launch attacks against their political opponents, newly created political parties that claimed to be successors to those existing before 1948. Around the same time, all Romanian numbers stations ceased transmitting, including a number station called "Ciocârlia/The Skylark", also known as "V01" after the revolution. Much of that sympathy was squandered during the Mineriads. Massive protests erupted in downtown Bucharest as political rallies organised by the opposition parties during the presidential elections, with a small part of the protesters deciding to stand ground even after Iliescu was re-elected with an overwhelming majority of 85%. Attempts by police to evacuate the remaining protesters resulted in attacks on state institutions, prompting Iliescu to appeal to the country's workers for help. Infiltrated and instigated by former Securitate agents, in the following days a large mass of workers, mainly miners, entered Bucharest and attacked and fought with anti-government protesters and gathered bystanders.
Sources: en.wikipedia.org
Camptocormia comes from two Greek words, meaning "to bend" (κάμπτω, kamptō) and "trunk" (κόρμος, kormos), and was coined by Alexandre-Achille Souques and B. Rosanoff-Saloff. These two men also created the definition of the disease that is widely accepted today. When the disorder was first clinically studied around the time of First World War, it was believed to be a psychogenic conversion disorder that resulted from the severe trauma of war. Souques and others treated patients with psychological therapy and early versions of electrotherapy. Samuel A. Sandler used a similar approach to treat soldiers during the Second World War. The view of BSS as a conversion disorder led to a lack of awareness about the conditions and few diagnoses by physicians. As time progressed and advances were made in knowledge of neuroscience and physiology, biological mechanisms behind the irregular bending were identified. The current medically preferred term for the condition is bent spine syndrome, because of the psychological origin associated with camptocormia.
== External links == Cerebral Folate Deficiency - description (2019) on the website of the National Organization for Rare Disorders (NORD). Neurodegeneration due to cerebral folate transport deficiency - description in the OMIM, a catalog of genetically-linked disorders.
Pronunciamiento ('pronouncement') is a term of Spanish origin for a type of coup d'état. Specifically the pronunciamiento is the formal declaration deposing the previous government and justifying the installation of the new government by the golpe de estado. Edward Luttwak distinguishes a coup, in which a military or political faction takes power for itself, from a pronunciamiento, in which the military deposes the existing government and hands over power to a new, ostensibly civilian government. A "barracks revolt" or cuartelazo is another type of military revolt, from the Spanish term cuartel ('quarter' or 'barracks'), in which the mutiny of specific military garrisons sparks a larger military revolt against the government.
== Impact and aftermath == Syrian rebels took advantage of the war, the heavy losses suffered by Hezbollah, and Hezbollah's absence in Syria to launch the 2024 Syrian opposition offensive on 27 November 2024 to overrun Syria's government-held territories. Hezbollah, which had previously sent forces, said they would not deploy troops, but later sent "supervising forces" to unsuccessfully attempt to repel the 2024 Homs offensive, as Homs is a key transport route for Iran to supply Hezbollah. In December 2024, the fall of Assad's Baathist regime in Syria was another blow to its Lebanese ally, Hezbollah, which was already weakened because of Israeli military actions. Following major operations in 2024, numerous analysts and experts have characterized the outcome as a significant victory for Israel. The Institute for the Study of War reported that Israeli operations effectively degraded Hezbollah's capabilities, leading to a ceasefire agreement on November 26, 2024, which mandated Hezbollah's disarmament in southern Lebanon. Hezbollah failed to accomplish its goal of compelling Israel to cease operations in the Gaza Strip, resulting in a weakened position within the region. Similarly, experts from the Atlantic Council noted that Israel's military actions, including the elimination of Hezbollah's leader, Hassan Nasrallah, significantly diminished the group's operational effectiveness.
Agouti signalling peptide adopts an inhibitor cystine knot motif. Along with the homologous Agouti-related peptide, these are the only known mammalian proteins to adopt this fold. The peptide consists of 131 amino acids. The lethal yellow mutation (Ay) was the first embryonic mutation to be characterized in mice, as homozygous lethal yellow mice (Ay/ Ay) die early in development, due to an error in trophectoderm differentiation. Lethal yellow homozygotes are rare today, while lethal yellow and viable yellow heterozygotes (Ay/a and Avy/a) remain more common. In wild-type mice agouti is only expressed in the skin during hair growth, but these dominant yellow mutations cause it to be expressed in other tissues as well. This ectopic expression of the agouti gene is associated with the yellow obese syndrome, characterized by early onset obesity, hyperinsulinemia and tumorigenesis.
Sources: en.wikipedia.org
It is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, containing seven amino acids with a lactam ring and a D-configured phenylalanine residue. It is supplied as a lyophilised powder for laboratory research.
The natural hormone is a linear tridecapeptide that is rapidly degraded in circulation. Melanotan-2 is shortened, cyclised, N-terminally acetylated, and carries a D-amino acid substitution, all of which slow enzymatic breakdown.
No national medicines regulator has approved melanotan-2 for therapeutic or cosmetic use. In several jurisdictions it is treated as an unapproved prescription medicine, and its legal classification differs from country to country.
No. It is a synthetic analogue carrying four amino acid changes, a lactam ring and an amidated C-terminus. The natural hormone is a linear thirteen-amino-acid peptide processed from proopiomelanocortin.