MC1R 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 2026-06-27 and is reviewed periodically as new material appears.
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.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, the naturally occurring peptide involved in pigmentation signalling. Its sequence is conventionally written as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, with a lactam bridge joining the aspartate side chain to the lysine side chain. The empirical formula is C50H69N15O9 and the monoisotopic mass lies near 1023.5 daltons. N-terminal acetylation and the D-configured phenylalanine both increase resistance to enzymatic breakdown compared with the parent hormone.
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.
=== Mental changes === The psychological effects of feminizing hormone therapy are harder to define than physical changes. Because hormone therapy is usually the first physical step taken to transition, the act of beginning it has a significant psychological effect, which is difficult to distinguish from hormonally induced changes. Changes in mood and well-being occur with hormone therapy in transgender women. Side effects of hormone therapy have the ability to significantly impact sexual functioning, either directly or indirectly through the various side effects, such as cerebrovascular disorders, obesity, and mood fluctuations. Some transgender women report a significant reduction in libido, depending on the dosage of antiandrogens. The effects of long-term hormonal regimens have not been conclusively studied and are difficult to estimate because research on the long-term use of hormonal therapy has not been noted. One study found that sex drive returned to baseline after three years of hormone therapy. It is possible to approximate outcomes of these therapies on transgender people based on their observed effect in cisgender men and women. Firstly, if one is to decrease testosterone in feminizing gender transition, it is likely that sexual desire and arousal would be inhibited; alternatively, if high doses of estrogen negatively impact sexual desire, which has been found in some research with cisgender women, it is hypothesized that combining androgens with high levels of estrogen would intensify this outcome.
=== Film and television === In the Adventure Time television series, the main antagonist is an evil, powerful undead being known simply as "The Lich". He describes himself as an ancient, cosmic being who is the manifestation of the inevitable death of all things.
A colorant is any substance that changes the spectral transmittance or reflectance of a material. Synthetic colorants are those created in a laboratory or industrial setting. The production and improvement of colorants was a driver of the early synthetic chemical industry, in fact many of today's largest chemical producers started as dye-works in the late 19th or early 20th centuries, including Bayer AG (1863). "Synthetics" achieve intensity, color fastness, and reproducibility that natural materials can rarely match. Market viable large scale production of dyes occurred nearly simultaneously in the early major producing countries United Kingdom of Great Britain and Ireland (1857), Second French Empire (1858), German Confederation (1858), and Switzerland (1859), and expansion of associated chemical industries followed. The mid-19th century through World War II saw an incredible expansion of the variety and scale of manufacture of synthetic colorants. Synthetic colorants quickly became ubiquitous in everyday life, from clothing to food. This stems from the invention of industrial research and development laboratories in the 1870s, and the new awareness of empirical chemical formulas as targets for synthesis by academic chemists. The dye industry became one of the first instances where directed scientific research lead to new products, and the first where this occurred regularly.
Journal of Military History. 65 (3): 617–640. doi:10.2307/2677528. JSTOR 2677528. S2CID 159945703. McEvedy, Colin; Jones, Richard (1978). Atlas of World Population History. Facts on File. ISBN 978-0-87196-402-1. McLynn, Frank (1998). Napoleon: A Biography. Pimlico. ISBN 978-0-7126-6247-5. Munch-Petersen, Thomas (2007). Defying Napoleon: How Britain Bombarded Copenhagen and Seized the Danish Fleet in 1807. Sutton. ISBN 978-0-7509-4280-5. Palmer, Robert Roswell (1941). Twelve who Ruled: The Committee of Public Safety, During the Terror. Princeton University Press. Palmer, Alan (1974). Alexander I: Tsar of War and Peace. Weidenfeld & Nicolson. ISBN 978-0-297-76700-8. Palmer, R. R.; Colton, Joel; Kramer, Lloyd (2013). A History of the Modern World: 11th Edition. McGraw-Hill Higher Education. ISBN 978-0-07-759962-1. Payne, Stanley G. (1973). A History of Spain and Portugal: Eighteenth Century to Franco. Vol. 2. Madison: University of Wisconsin Press. ISBN 978-0299062705. Retrieved 2 May 2021. Philo, Tom (2010), Military and Civilian War Related Deaths Through the Ages, archived from the original on 20 April 2010 Rapport, Mike (2013). The Napoleonic Wars: A Very Short Introduction. OUP Oxford. ISBN 978-0-19-164251-7. Riehn, Richard K. (1990). 1812: Napoleon's Russian Campaign. McGraw-Hill. ISBN 978-0-07-052731-7. Riehn, Richard K. (1991), 1812: Napoleon's Russian Campaign (Paperback ed.), New York: Wiley, ISBN 978-0-471-54302-2 Riley, J. P. (2013). Napoleon and the World War of 1813: Lessons in Coalition Warfighting. Routledge. ISBN 978-1-136-32135-1. Roberts, Andrew (2014).
Lysyl oxidase has also proven crucial to the development of the respiratory system and the skin, as collagen and elastin represent 50-60% of the composition of the lung, and 75% of the skin. In Lox homozygous null models (Lox -/-), the activity of LOX was reduced by up to 80%, and the phenotype of the lungs resembles those of patients with emphysema and dilated distal airways. Lysyl oxidase plays a crucial role in the commitment step of adipocyte, or fat cell, formation from pluripotent stem cells during development. Its absence may lead to defects in the transforming growth factor beta superfamily of proteins, which control cell growth and differentiation.
Sources: en.wikipedia.org
== External links == "Burkholderia pseudomallei genomes and related information". PATRIC. NIAID. Archived from the original on 2011-08-24. Retrieved 2010-06-24. "Getting a Grip on the Great Mimicker: Secrets of a Stealth Organism". Wellcome Trust. Archived from the original on 2009-09-27. Retrieved 2006-03-27. Pathema Burkholderia resource "Burkholderia pseudomallei". NCBI Taxonomy Browser. 28450.
Lagering Lagers are stored at cellar temperature or below for 1–6 months while still on the yeast. The process of storing, or conditioning, or maturing, or aging a beer at a low temperature for a long period is called "lagering", and while it is associated with lagers, the process may also be done with ales, with the same result – that of cleaning up various chemicals, acids and compounds.
This policy was spearheaded by Minister of War Winston Churchill. France, Japan and the United States also sent forces to help decide the Russian Civil War in the Whites’ favor. Lenin made peace overtures to Wilson, and the American leader responded by sending diplomat William Bullitt to Moscow. The Allies ultimately rejected the ceasefire terms which Bullitt negotiated, believing that a White victory was imminent. However, the Bolsheviks, operating a unified command from a central location, defeated all the opposition one by one and took full control of Russia, as well as breakaway provinces such as Ukraine, Georgia, Armenia, and Azerbaijan. Bainbridge Colby, the American Secretary of State, in 1920 announced an American policy of refusing to deal with the new regime. Soviet Russia found itself isolated in international diplomacy. Lenin stated that the Soviet Union was surrounded by a "hostile capitalist encirclement" and he viewed diplomacy as a weapon to keep Soviet enemies divided. Lenin set up the Comintern, which called for revolutionary upheavals in capitalist countries. Nevertheless, Communist revolutions failed in Germany, Bavaria, and Hungary and by the mid-1920s Moscow was no longer fomenting revolution.
==== Satiety ==== As a peptide hormone, CCK mediates satiety by acting on the CCK receptors distributed widely throughout the central nervous system. The mechanism for hunger suppression is thought to be a decrease in the rate of gastric emptying. CCK also has stimulatory effects on the vagus nerve, effects that can be inhibited by capsaicin. The stimulatory effects of CCK oppose those of ghrelin, which has been shown to inhibit the vagus nerve. The effects of CCK vary between individuals. For example, in rats, CCK administration significantly reduces hunger in adult males, but is slightly less effective in younger subjects, and even slightly less effective in females. The hunger-suppressive effects of CCK also are reduced in obese rats.
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.