melanocortin receptor 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 2026-07-29. Numbers and descriptions here follow the published literature rather than marketing material.
Melanotan-2 is frequently confused with afamelanotide, a linear analogue authorised in the European Union for erythropoietic protoporphyria. The two compounds differ in chain length, ring structure and receptor selectivity, so findings for one cannot be transferred directly to the other. Published controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports. Questions about effect size, dose-response behaviour and long-term safety therefore remain unresolved.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence incorporates a lactam bridge that constrains the peptide into a ring, which increases resistance to enzymatic breakdown relative to the natural hormone. Researchers at the University of Arizona synthesised the compound in the late 1980s and early 1990s while studying pigmentation pathways. It has never received marketing approval from any national medicines regulator. In the scientific literature it is usually described as a laboratory research reagent rather than a therapeutic product.
Scientific discussion of Melanotan-2 spans pharmacology, dermatology, and public-health literature. Laboratory studies examine its receptor binding and cellular effects, while clinical reports describe outcomes observed after unregulated use. These two bodies of work differ in rigour and intent. Peer-reviewed trials of the compound as a medicine are limited, so much of the available information comes from case reports and surveillance data. Authors frequently note the gap between experimental findings and real-world use.
Reported observations after unregulated use include shifts in skin pigmentation and, in some accounts, unintended changes to moles and other lesions. Whether these outcomes are causally linked to the compound, and how often they occur, remain open questions because controlled data are scarce. The absence of standardised dosing and verified product purity complicates interpretation. Researchers have called for better surveillance and analytical characterisation of samples obtained outside regulated channels. Conclusions drawn from anecdotal evidence should be treated as provisional.
Melanotan-2 has not received marketing authorisation from major regulatory agencies for any therapeutic indication. Several jurisdictions classify it as a prescription-only medicine or a controlled substance when supplied for human use. Because approved products do not exist, material sold online usually sits outside pharmaceutical supply chains and formal quality oversight. Regulators have issued public notices describing the compound as unapproved. Enforcement varies, and the legal position differs between countries, which complicates any single general statement about its status.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Alpha-MSH analogue with a lactam ring |
| Molecular formula | C50H69N15O9 | Commonly cited value for the neutral peptide |
| Molecular weight | 1024.18 g/mol | Calculated for the free molecule |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water, DMSO and ethanol | Dissolution in pure water is often slow |
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.
Routine characterisation relies on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, using a C18 column and a water-acetonitrile gradient containing trifluoroacetic acid. Electrospray ionisation mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidised by-products that co-elute poorly. Sequence and stereochemistry require additional work, such as peptide mapping or amino acid analysis, because a chromatographic purity figure alone does not distinguish a diastereomer from the target peptide. Independent testing of research-grade material frequently shows measured content below the stated label, so a certificate of analysis is best read together with the method that produced it.
Melanotan-2 is handled in the laboratory as a lyophilised powder that dissolves readily in water, dimethyl sulfoxide and dimethylformamide, with limited solubility in ethanol. Stock solutions prepared in an organic solvent often precipitate when diluted into aqueous buffer, so gradual dilution with mixing is standard practice. The peptide carries a tryptophan residue and a histidine residue, both sensitive to oxidation and to alkaline conditions. Working solutions are therefore kept near neutral to slightly acidic pH, protected from light, and consumed within the same working session whenever that is practical.
Receptor binding at MC1R on melanocytes raises intracellular cyclic AMP and increases expression of tyrosinase and related enzymes. The downstream result is greater synthesis of eumelanin, the dark pigment, without ultraviolet exposure acting as the trigger. The compound is not selective, however, and also engages MC3R, MC4R and MC5R, which are expressed in the central nervous system and elsewhere. That lack of selectivity is the explanation usually offered for effects reported outside pigmentation, including appetite suppression and nausea. Selectivity remains a central theme in comparative studies of related peptides.
Human data remain limited and mostly short-term. Reports describe small trials and observational accounts rather than large controlled studies, so questions about dose-response relationships and long-term effects on melanocytes stay open. Whether repeated exposure alters naevus behaviour is not settled in the published record. Researchers also note that self-administered use outside clinical settings makes actual exposure difficult to quantify. Statements about efficacy and safety should therefore be read as preliminary rather than established.
Melanotan II is a synthetic cyclic heptapeptide that acts as an agonist at melanocortin receptors. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous peptide involved in pigment production. The analogue carries a lactam bridge that constrains the ring and slows enzymatic breakdown relative to the native hormone. In research literature it appears under several abbreviations, and naming conventions are not fully standardized. Published descriptions usually place it within the broader melanocortin agonist family.
According to a 2011 article by the Lawyers Collective, an NGO in India, "32 countries impose capital punishment for offences involving narcotic drugs and psychotropic substances." South Korean law provides for capital punishment for drug offences, but South Korea has a de facto moratorium on capital punishment as there have been no executions since 1997, even though there are still people on death row and new death sentences continue to be handed down.
Once released into the air, VOCs can undergo reactions with ozone and hydroxyl radicals to produce other VOCs, such as formaldehyde. Health effects include eye, nose, and throat irritation; headaches, loss of coordination, nausea; and damage to the liver, kidney, and central nervous system. Testing emissions from building materials used indoors has become increasingly common for floor coverings, paints, and many other important indoor building materials and finishes. Indoor materials such as gypsum boards or carpet act as VOC 'sinks', by trapping VOC vapors for extended periods of time, and releasing them by outgassing. The VOCs can also undergo transformation at the surface through interaction with ozone. In both cases, these delayed emissions can result in chronic and low-level exposures to VOCs. Several initiatives aim to reduce indoor air contamination by limiting VOC emissions from products. There are regulations in France and in Germany, and numerous voluntary ecolabels and rating systems containing low VOC emissions criteria such as EMICODE, M1, Blue Angel and Indoor Air Comfort in Europe, as well as California Standard CDPH Section 01350 and several others in the US. Due to these initiatives an increasing number of low-emitting products became available to purchase.
== Honors and awards == 2010 American Chemical Society The Delaware Section Award 2015 Dupont Pederson Medal 2016 the Analytical Scientist The Power List 2016 Top 50 most influential women 2020 Eastern Analytical Symposium (EAS) Award for Outstanding Achievements in Mass Spectrometry
=== Announcement and delay === Valve announced Half-Life 2 at E3 2003, with demonstrations of the characters, animation and physics. The reaction was positive, and the game won the E3 Game of the Show award. Newell also announced a release date of September 30, 2003, hoping this would motivate the team. They worked long hours to meet the deadline, but by July it was clear they would miss it. Rumors spread of a delay. On September 23, Valve released a statement targeting a release for the holiday season, leading to fan backlash. Newell had been hesitant to announce a delay without a new release date. He said later: "We were paralyzed. We knew we weren't going to make the date we promised, and that was going to be a huge fiasco and really embarrassing. But we didn't have a new date to give people either." The graphics card manufacturer ATI had arranged a promotional event on Alcatraz Island to coincide with the planned release of Half-Life 2. Unable to pull out of the event, Newell gave a prepared speech, demonstrated the Source engine, and left without addressing questions.
Sources: en.wikipedia.org
== Music == A musicologist, disciple and collaborator of Dom Prosper Guéranger, Dom Pothier contributed to the reconstitution, the restoration and the renewal of the Gregorian chant, a form of monophonic, unaccompanied sacred song of the Roman Catholic Church. Besides being the composer of many Gregorian songs (Officium Defunctorum, 1887) and the writer of a huge number of articles, Dom Pothier was also the head and editor of the Revue du Chant Grégorien (1892–1914) - supervising the publication of several works (Hymnes, Christmas office, Antifonario, Cantus mariales) -, the founder of the Paléographie Musicale publication for the dissemination of medieval liturgical manuscripts, and the author of a new edition of the choir books based on manuscripts of the Gregorian chant and of several studies on the plainchant, including Les mélodies grégoriennes d'après la tradition (Gregorian Melodies According to the Tradition), 1880, his chief work which became the standard work on the subject. Dom Pothier was appointed president of the newly created Pontifical Commission on the Vatican Edition of the Gregorian Liturgical Books by Pope Pius X in 1904. As chairman of this commission for the reconstitution of the music of the Roman Catholic Mass, Dom Pothier lived in Rome from 1904 till 1913. His Liber Gradualis, 1883, marked the beginning of a reform in liturgical chant and was used as a basis for the Gradual Vatican which was published, under his responsibility, in 1908.
The Monovalent Cation:Proton Antiporter-2 (CPA2) Family (TC# 2.A.37) is a moderately large family of transporters belonging to the CPA superfamily. Members of the CPA2 family have been found in bacteria, archaea and eukaryotes. The proteins of the CPA2 family consist of between 333 and 900 amino acyl residues and exhibit 10-14 transmembrane α-helical spanners (TMSs).
In conventional nomenclature, the carbons to which the phosphate groups attach are the 3'-end and the 5'-end carbons of the sugar. This gives nucleic acids directionality, and the ends of nucleic acid molecules are referred to as 5'-end and 3'-end. The nucleobases are joined to the sugars via an N-glycosidic linkage involving a nucleobase ring nitrogen (N-1 for pyrimidines and N-9 for purines) and the 1' carbon of the pentose sugar ring. Non-standard nucleosides are also found in both RNA and DNA and usually arise from modification of the standard nucleosides within the DNA molecule or the primary (initial) RNA transcript. Transfer RNA (tRNA) molecules contain a particularly large number of modified nucleosides.
== Death == On April 17, 2002, Staley's mother went to his apartment to inform him about the death of Demri Lara Parrott's brother, but there was no answer. On April 19, Staley's accountants contacted his former manager, Susan Silver, and told her that no money had been withdrawn from the singer's bank account in two weeks. Silver then contacted Staley's mother, who went back to his apartment and discovered delivered mail by his door. Staley owned a cat named Sadie at the time, who was usually quiet; upon hearing Sadie meow, Staley's mother became worried the animal was distressed and that Staley might be in trouble. Still not receiving an answer, McCallum called 9-1-1 to say she had not heard from him "in about two weeks". She entered the apartment with police and her ex-husband, Jim Elmer. It was reported that the 6-foot (183 cm) Staley weighed only 86 pounds (39 kg) when his partially decomposed body was discovered. Medical examiners had to identify the body by comparing dental records. The autopsy and toxicology report revealed that Staley had died from a mixture of heroin and cocaine, known as a speedball. The autopsy concluded that Staley had died two weeks before his body was found, on April 5—the same day fellow grunge musician Kurt Cobain committed suicide eight years prior. His death was classified as "accidental". Staley's Alice in Chains bandmates issued the following statement:
The Soviet communist state system was based on unified state power and democratic centralism. The highest organ of state authority, the Supreme Soviet of the Soviet Union, stood above all other state organs and worked under the leadership of the Communist Party of the Soviet Union. The executive organ of the state (synonymous with government), the Council of Ministers, was an internal organ of the All-Union Supreme Soviet.
Sources: en.wikipedia.org
The birds were a food and fuel source for early European settlers, and are now farmed, in Australia and elsewhere, for their meat, oil and leather. Commercial emu farming started in Western Australia around 1970. The commercial industry in the country is based on stock bred in captivity, and all states except Tasmania have licensing requirements to protect wild emus. Outside Australia, emus are farmed on a large scale in North America, with about 1 million birds in the US, Peru, and China, and to a lesser extent in some other countries. Emus breed well in captivity, and are kept in large open pens to avoid the leg and digestive problems that arise from inactivity. They are typically fed on grain supplemented by grazing, and are slaughtered at 15 to 18 months. The Salem district administration in India advised farmers in 2012 not to invest in the emu business which was being heavily promoted at the time; further investigation was needed to assess the profitability of farming the birds in India. In the United States, it was reported in 2013 that many ranchers had left the emu business; it was estimated that the number of growers had dropped from over five thousand in 1998 to one or two thousand in 2013. The remaining growers increasingly rely on sales of oil for their profit, although, leather, eggs, and meat are also sold.
Pre-preg is a composite material made from "pre-impregnated" fibers and a partially cured polymer matrix, such as epoxy or phenolic resin, or even thermoplastic mixed with liquid rubbers or resins. The fibers often take the form of a weave and the matrix is used to bond them together and to other components during manufacture. The thermoset matrix is only partially cured to allow easy handling; this B-Stage material requires cold storage to prevent complete curing. B-Stage pre-preg is always stored in cooled areas since heat accelerates complete polymerization. Hence, composite structures built of pre-pregs will mostly require an oven or autoclave to cure. The main idea behind a pre-preg material is the use of anisotropic mechanical properties along the fibers, while the polymer matrix provides filling properties, keeping the fibers in a single system.
Political corruption is the use of legislated powers by government officials for illegitimate private gain. Misuse of government power for other purposes, such as repression of political opponents and general police brutality, is not considered political corruption. Neither are illegal acts by private persons or corporations not directly involved with the government. An illegal act by an officeholder constitutes political corruption only if the act is directly related to their official duties. Forms of corruption vary, but include bribery, extortion, cronyism, nepotism, patronage, graft, and embezzlement. While corruption may facilitate criminal enterprise such as drug trafficking, money laundering, and human trafficking, it is not restricted to these activities. The activities that constitute illegal corruption differ depending on the country or jurisdiction. For instance, certain political funding practices that are legal in one place may be illegal in another. In some cases, government officials have broad or poorly defined powers, which make it difficult to distinguish between legal and illegal actions. Worldwide, bribery alone is estimated to involve over 1 trillion US dollars annually. A state of unrestrained political corruption is known as a kleptocracy, literally meaning "rule by thieves".
=== Increased MPV === Immune thrombocytopenia Disseminated intravascular coagulation Myeloproliferative disorders Administration of erythropoietin / thrombopoietin Recovery from transient hypoplasia Gray platelet syndrome GATA-1 mutation vWD Type 2B Platelet Type vWD Paris-Trousseau syndrome Mediterranean macrothrombocytopenia Bernard–Soulier syndrome MYH9-related disorders 21q11 deletion syndrome Chronic myelogenous leukemia Post-splenectomy Vasculitis Diabetes mellitus Pre-eclampsia Chronic kidney disease Respiratory diseases Thrombocytopenia secondary to sepsis Hyperthyroidism Hypothyroidism Myocardial infarction Artificial heart valves Massive hemorrhage
=== FastGC === Gas chromatography (GC) in combination with mass spectrometry (GC-MS) is capable of separating isomeric compounds. Although GC has been successfully coupled to PTR-MS in the past, this approach annihilates the real-time capability of the PTR-MS technology, because a single GC analysis run typically takes between 30 min and 1 h. Thus, state-of-the-art GC add-ons for PTR-MS are based on fastGC technology. Materic et al. utilized an early version of a commercially available fastGC addon in order to distinguish various monoterpene isomers. Within a fastGC run of about 70 s they were able to separate and identify: alpha-pinene, beta-pinene, camphene, myrcene, 3-carene and limonene in a standard mixture, Norway spruce, Scots pine and black pine samples, respectively. Particularly, if the operation mode of a PTR-MS instrument equipped with fastGC is continuously switched between fastGC and direct injection (dependent on the application, e.g. a loop sequence of one fastGC run followed by 10 min of direct injection measurement), real-time capability is preserved, while at the same time valuable information on substance identification and isomer separation is acquired.
Sources: en.wikipedia.org
It is a synthetic cyclic heptapeptide modelled on alpha-melanocyte-stimulating hormone. A lactam bridge links two side chains, forming a ring that stabilises the molecule against proteolysis. It belongs to the broader melanocortin peptide family.
No national medicines agency has approved melanotan-2 for clinical use. Afamelanotide, a related but distinct peptide, holds a marketing authorisation in the European Union for a rare photosensitivity disorder. Melanotan-2 itself is handled as a laboratory chemical.
Its broad activity across melanocortin receptors makes it a tool for probing pigmentation, appetite and vascular signalling. Early trials recorded skin darkening and other effects that were not the original focus of the work. Those observations generated hypotheses that later studies have examined.
Major regulatory agencies have not approved it for any indication. Some countries permit it only under prescription frameworks, while others classify it as a controlled substance.