If you have been reading about alpha-MSH and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-08-26. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Melanocortin receptors comprise five subtypes with distinct tissue distributions and functions. Melanotan-2 is described in the literature as a non-selective agonist that engages several of these subtypes, including MC1R, MC3R, MC4R, and MC5R. MC1R is the subtype most directly linked to melanin production in skin cells. Because the compound is not subtype-selective, its observed effects in experimental settings are generally attributed to activity across multiple receptor pathways rather than to a single target.
Melanotan-2 is a synthetic linear peptide built from seven amino acids arranged in a short chain. Its sequence is commonly written as Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH2, which includes a modified N-terminus and an amidated C-terminus. The molecule belongs to the melanocortin family and acts as a receptor agonist. Structural features such as the D-phenylalanine residue and the Nle substitution are associated with increased stability against enzymatic degradation relative to the natural parent peptide.
| 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 |
Receptor studies place melanotan-2 among non-selective melanocortin agonists, binding MC1R, MC3R, MC4R and MC5R rather than a single subtype. Activation of MC1R on cutaneous melanocytes raises tyrosinase activity and shifts pigment synthesis toward eumelanin, which is darker and more photostable than pheomelanin. Central receptors, particularly MC4R, are associated with appetite suppression and with reported effects on sexual function. Because subtype selectivity is low, the same molecule engages pigment, metabolic and vascular pathways at once, and this breadth is a common explanation offered for the range of adverse events described in user reports.
No regulatory authority has approved melanotan-2 for human use, and several countries classify it as a prescription-only or controlled substance, which restricts lawful supply. Material sold online is generally labelled as a research chemical and is not required to meet pharmaceutical standards of identity or purity. Published human data consist mainly of small uncontrolled studies, case reports and adverse-event notifications, so the evidence base is descriptive rather than confirmatory. Whether repeated melanocyte stimulation alters long-term naevus behaviour remains an open question that no completed trial has resolved.
== Other aspects and examples == In the CCS system, carbon chain lengths are denoted by celestial stems (甲 jiǎ, 乙 yǐ, 丙 bǐng, 丁 dīng, 戊 wù, 己 jǐ, 庚 gēng, 辛 xīn, 壬 rén, 癸 guǐ), characters used since the Shang dynasty (16th–11th centuries BCE) for naming days (and later, to name years). For example, hexane is 己烷 jǐwán, since 己 jǐ is the sixth celestial stem. Longer carbon chains are specified by number followed by '碳' tàn 'carbon'. For example, 1-hexadecene is 1-十六碳烯 (read as [1, yī] [-, wèi] [十六, shíliù, '16'] [碳, tàn] [烯, xī]), where the hyphen is read as 位 (wèi, 'position'). For a more complex example, consider 3-buten-1-ol. Its Chinese name is 3-丁烯-1-醇 (read as [3, sān] [-, wèi] [丁, dīng] [烯, xī] [1, yī] [-, wèi] [醇, chún]). The descriptors for degree of substitution, primary, secondary, tertiary, and quaternary, are translated as 伯 (bó), 仲 (zhòng), 叔 (shū), 季 (jì), which refer to the first, second, third, and fourth male siblings in a family. For instance, tert-butyllithium is translated as 叔丁基锂 ([叔, shū, 'tert'], [丁, dīng, 'but-'], [基, jī, 'yl'], [锂, lǐ, 'lithium']). Other commonly used isomeric descriptors normal-, iso-, and neo- are translated as 正 (zhèng, 'proper'), 异 (yì, 'different'), and 新 (xīn, 'new'), respectively. The numerical prefix bis- is translated as 双 (shuāng, 'double'), while larger multiplicities are simply given by the Chinese word for the number (e.g., 四 (sì, 'four') for tetrakis-). For example, tetrakis(triphenylphosphine)palladium is rendered 四(三苯基膦)钯, in which 三苯基膦 is triphenylphosphine and 钯 is palladium.
According to the Constitution of the Russian Federation, Moscow is an independent federal subject of the Russian Federation, a city of federal importance. The Mayor of Moscow is the leading official in the executive, leading the Government of Moscow, which is the highest organ of executive power. The Moscow City Duma is the city duma (city council or local parliament), and local laws must be approved by it. It includes 45 members who are elected for a five-year term on a single-mandate constituency basis. From 2006 to 2012, direct elections of the mayor were not held because of changes in the Charter of the city of Moscow, with the mayor appointed by presidential decree. The first direct elections since the 2003 vote were scheduled to be held after the expiration of the then-current mayor's term in 2015; however, because he voluntarily resigned, these elections took place in September 2013. Local administration is carried out through 11 prefectures—which unify Moscow's districts into administrative districts on a territorial basis—and 125 regional administrations. According to the law "On the organization of local self-government in the city of Moscow", since the beginning of 2003, the executive bodies of local self-government are municipalities; representative bodies are municipal assemblies, whose members are elected in accordance with the Charter of the intracity municipality.
The production of pure alkali metals is somewhat complicated due to their extreme reactivity with commonly used substances, such as water. From their silicate ores, all the stable alkali metals may be obtained the same way: sulfuric acid is first used to dissolve the desired alkali metal ion and aluminium(III) ions from the ore (leaching), whereupon basic precipitation removes aluminium ions from the mixture by precipitating it as the hydroxide. The remaining insoluble alkali metal carbonate is then precipitated selectively; the salt is then dissolved in hydrochloric acid to produce the chloride. The result is then left to evaporate and the alkali metal can then be isolated. Lithium and sodium are typically isolated through electrolysis from their liquid chlorides, with calcium chloride typically added to lower the melting point of the mixture. The heavier alkali metals, however, are more typically isolated in a different way, where a reducing agent (typically sodium for potassium and magnesium or calcium for the heaviest alkali metals) is used to reduce the alkali metal chloride. The liquid or gaseous product (the alkali metal) then undergoes fractional distillation for purification. Most routes to the pure alkali metals require the use of electrolysis due to their high reactivity; one of the few which does not is the pyrolysis of the corresponding alkali metal azide, which yields the metal for sodium, potassium, rubidium, and caesium and the nitride for lithium. Lithium salts have to be extracted from the water of mineral springs, brine pools, and brine deposits.
=== Finland === The sale and production of alcohol was prohibited in Finland from 1919 to 1932; no current prohibition of absinthe exists. The government-owned chain of liquor stores (Alko) is the only outlet that may sell alcoholic beverages containing over 8% ABV, although national law bans the sale of alcoholic beverages containing over 80% ABV.
The use of bioorthogonal chemistry typically proceeds in two steps. First, a cellular substrate is modified with a bioorthogonal functional group (chemical reporter) and introduced to the cell; substrates include metabolites, enzyme inhibitors, etc. The chemical reporter must not alter the structure of the substrate dramatically to avoid affecting its bioactivity. Secondly, a probe containing the complementary functional group is introduced to react and label the substrate. Although effective bioorthogonal reactions such as copper-free click chemistry have been developed, development of new reactions continues to generate orthogonal methods for labeling to allow multiple methods of labeling to be used in the same biosystems. Carolyn R. Bertozzi was awarded the Nobel Prize in Chemistry in 2022 for her development of click chemistry and bioorthogonal chemistry.
Sources: en.wikipedia.org
=== From primary cancer to the meninges === NM is a secondary cancer meaning that it is the result of neoplastic cells that have metastasized from a primary cancer site. These cancers develop an enzyme that is able to break down blood vessels at a microscopic level. These cells enter the blood vessels and travel across the body. Once the brain is reached, they break down the blood–brain barrier to enter the Cerebrospinal Fluid (CSF). There the cancerous cells seed and disseminate into the leptomeninges which are composed of the arachnoid and the pia. The CSF continues to carry neoplastic cells through the brain tracts and spreads the cancerous cells. Lung cancer, breast cancer, and melanoma comprise the majority of solid tumors spreading to the leptomeninges. Although rare, meningeal carcinomatosis can arise from cervical cancer. Only eight cases of MC arising from squamous cell carcinoma of the uterine cervix are previously reported in the literature. Since NM is a result of primary cancer metastasis and can develop from primary brain tumors or parenchymal metastasis when tumor cells are lodged in small central nervous system (CNS) vasculature, causing local ischemia and vessel damage which result in tumor spillage into the Virchow-Robin spaces and providing access to the subarachnoid space.
=== Genetics === In MCTD, major histocompatibility complex (MHC) and non-MHC genes have been linked to disease vulnerability. HLA-DR4 in the MHC is linked to both anti-RNP antibody responses and MCTD. The HLA class II phenotype/genotype most closely connected with scleroderma, HLA-DR5, and its subgroups, has been demonstrated to have a negative connection with MCTD. Another genetic feature of MCTD is the presence of anti-RNP antibodies. However, these antibodies are not present in all patients. Genome-wide association studies have revealed that there are parts of a patient’s genetic material that cause production of these anti-RNP antibodies. The mechanism is not yet thoroughly defined.
=== Biosynthesis === Cannabinoid production begins with an enzyme combining geranyl pyrophosphate and olivetolic acid to form CBGA. CBGA is converted to THCA, CBDA, or CBCA by separate synthases, FAD-dependent dehydrogenase enzymes that diverged from a promiscuous common ancestor. There is no enzymatic conversion of CBDA or CBD to THCA or THC. Propyl homologues (CBGVA, THCVA, CBDVA, CBCVA) follow an analogous pathway from divarinolic acid.
The musical forms of punk and hip hop both originated in the United States in the 1970s. The United States has the world's largest music market, with a total retail value of $15.9 billion in 2022, and is the largest exporter of music. Most of the world's major record companies are based in the U.S.; they are represented by the Recording Industry Association of America (RIAA). Mid-20th-century American pop stars, such as Frank Sinatra and Elvis Presley, became global celebrities and best-selling music artists, as have artists of the late 20th century, such as Michael Jackson, Madonna, Whitney Houston, and Mariah Carey, and of the early 21st century, such as Eminem, Britney Spears, Lady Gaga, Katy Perry, Taylor Swift and Beyoncé.
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. Melanotan-2 is manufactured synthetically. The naturally occurring peptide in the same family is alpha-melanocyte-stimulating hormone, which the body produces as part of normal endocrine and neural signalling.