If you have been reading about melanocortin receptor 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.
Last reviewed on 2025-10-17. 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.
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.
The compound emerged from research programs in the 1980s that examined analogues of alpha-melanocyte-stimulating hormone for pigmentation and photoprotection. Investigators modified the native sequence to extend activity duration and potency. A related analogue, afamelanotide, was developed within the same broad line of inquiry and eventually gained approval in certain jurisdictions for a rare light-sensitivity condition. Melanotan-2 itself did not progress through the same regulatory route and has no approved therapeutic indication.
| 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.
== Function and location == The OXTR protein belongs to the G protein-coupled receptor (GPCR) family, specifically Gq, and acts as a receptor for oxytocin. Its activity is mediated by G proteins that activate several different second messenger systems. Oxytocin receptors are expressed by the myoepithelial cells of the mammary gland, and in both the myometrium and endometrium of the uterus at the end of pregnancy. The oxytocin receptor system plays an important role as an inducer of uterine contractions during parturition and of milk ejection. OXTR is also associated with the central nervous system. The gene is believed to play a major role in social, cognitive, and emotional behavior. A decrease in OXTR expression by methylation of the OXTR gene is associated with callous and unemotional traits in adolescence, rigid thinking in anorexia nervosa, problems with facial and emotional recognition, and difficulties in the affect regulation. A reduction in this gene is believed to lead to prenatal stress, postnatal depression, and social anxiety. Studies on OXTR methylation—which downregulates oxytocin mechanisms—suggest this process is associated with increased gray matter density in the amygdala, implicating OXTR regulation in stress and parasympathetic regulation. Social isolation has been found to decrease oxytocin receptor levels in rodents, whereas levels of oxytocin were unchanged.
Food plays various roles in social and cultural life. In Chinese folk religion, ancestor veneration is conducted by offering food to ancestors and Chinese festivals involve the consumption and preparation of specific foods which have symbolic meanings attached to them. Specific religions in China have their own cuisines such as the Taoist diet, Buddhist cuisine and Chinese Islamic Cuisine. The Kaifeng Jews in Henan province once had their own Chinese Jewish cuisine but the community has largely died out in the modern era and not much is known about the specifics of their cuisine but they did influence foods eaten in their region and some of their dishes remain. Chinese dishes with purported Kaifeng Jewish roots include Kaifeng xiao long bao, Mayuxing bucket-shaped chicken, Chrysanthemum hot pot, and Four Treasures. Food also plays a role in daily life. The formality of the meal setting can signify what kind of relationship people have with one another, and the type of food can indicate ones' social status and their country of origin. In a formal setting, up to sixteen of any combination of hot and cold dishes would be served to respect the guests. On the other hand, in a casual setting, people would eat inexpensive meals such as at food stalls or homemade food. The typical disparity in food in the Chinese society between the wealthy and everyone below that group lies in the rarity and cost of the food or ingredient, such as shark fins and bear paws.
June 19, 1987: Law concerning the duration and organization of working time. July 22, 1987: Law on the exercise of parental authority. July 18, 1988: Creation of the Secretary of State for Women's Rights, assigned to Michèle André. December 28, 1988: Order concerning the possession, distribution, dispensing, and administration of the drug Mifepristone 200 mg tablets. May 16, 1989: Decree removing the managerial and technical staff of the prison administration's external services from the list of positions for which separate recruitment could be planned for men and women. July 10, 1989: Framework law on education. July 10, 1989: Law on the prevention of child abuse and the protection of children. February 20, 1990: Order amending the order of November 3, 1988, concerning the prices of care and hospitalization related to voluntary termination of pregnancy. July 6, 1990: Law amending the Social Security Code and relating to family benefits and employment assistance for the care of young children. September 5, 1990: Marital rape is recognized for the first time by the Court of Cassation. December 21, 1990: The Council of State validates the conformity of the 1975 Veil Law with the European Convention on Human Rights. January 18, 1991: Law containing provisions relating to public health and social insurance. January 31, 1991: Decree concerning the responsibilities of the Secretary of State for Women's Rights and Daily Life, delegated by the Minister of Labour, Employment, and Vocational Training. May 1991: Édith Cresson becomes the first female Prime Minister of France.
== Bibliography == K.F. Warner, "Boning Lamb Cuts", Leaflet 74, U.S. Department of Agriculture, Bureau of Animal Industry, June 1931. full text. Bob Kennard, "Much ado about mutton". Ludlow: Merlin Unwin, 2014.
As an example of varying pressures, a finger can be pressed against a wall without making any lasting impression; however, the same finger pushing a thumbtack can easily damage the wall. Although the force applied to the surface is the same, the thumbtack applies more pressure because the point concentrates that force into a smaller area. Pressure is transmitted to solid boundaries or across arbitrary sections of fluid normal to these boundaries or sections at every point. Unlike stress, pressure is defined as a scalar quantity. The negative gradient of pressure is called the force density. Another example is a knife. If the flat edge is used, force is distributed over a larger surface area resulting in less pressure, and it will not cut. Whereas using the sharp edge, which has less surface area, results in greater pressure, and so the knife cuts smoothly. This is one example of a practical application of pressure. For gases, pressure is sometimes measured not as an absolute pressure, but relative to atmospheric pressure; such measurements are called gauge pressure. An example of this is the air pressure in an automobile tire, which might be said to be "220 kPa (32 psi)", but is actually 220 kPa (32 psi) above atmospheric pressure. Since atmospheric pressure at sea level is about 100 kPa (14.7 psi), the absolute pressure in the tire is therefore about 320 kPa (46 psi). In technical work, this is written "a gauge pressure of 220 kPa (32 psi)".
Sources: en.wikipedia.org
On 16 February, the Syrian government forces intensified their drone attacks, which resulted in the death of one person and five injuries in the Mansoura-Walgha village area. A car exploded in Al-Qurayya, injuring two people, a Syrian source stated that the car was carrying weapons and ammunition. On 17 February, the emir of Dar Ara, Abu Yahya Hassan Al-Atrash, defected to the Syrian government forces, arriving at Daraa Governorate from Suwayda, sources stated that Hikmat al-Hijri does not want other leaders in Suwayda, except him. On 19 February, an unknown group kidnapped Yahya al-Hajjar, the former leader of Men of Dignity, on his farm in rural Suwayda, the Men of Dignity declared a state of maximum alert immediately after the kidnapping, when al-Hajjar was released, he was taken to the guesthouse of the Men of Dignity leader, Sheikh Mazid Khaddaj. On 22 February, the Syrian government forces launched attacks toward Al-Majdal, the National Guard responded to the attacks. On 24 February, an armed group from the village of Labin attacked the Internal Security Forces after an attempt to free one of its members who had been arrested for theft. At the Suwayda headquarters of the Criminal Security branch, the Rapid Intervention Battalion, led by Ruad Abdul Khaliq, clashed with a group from the Abu Sarhan family.
== Career == Coon was a postdoctoral student in Donald Hunt's lab at the University of Virginia from 2002 to 2005. There Joshua Coon and John Syka developed electron-transfer dissociation (ETD). In 2005, Coon joined the University of Wisconsin-Madison. He became an associate professor in 2010, and a professor in 2012.
== Research == Flunarizine may help to reduce the severity and duration of attacks of paralysis associated with the more serious form of alternating hemiplegia, as well as being effective in rapid onset dystonia-parkinsonism (RDP). Both these conditions arise from specific mutations in the ATP1A3 gene. Flunarizine extended motor neuron survival in spinal cord, protected skeletal muscles from cell death and atrophy and extended survival by 40% in an animal model of spinal muscular atrophy. Flunarizine has also shown promise as an anti-prion medication.
=== Spoon test === The spoon test, developed in 1964 by Ernest Bors, relies on assessment of the smooth movement of the convex side of a spoon along the surface of the patient's skin. In patients with sudomotor dysfunction, the spoon will slide in a smooth and uninterrupted fashion. Conversely, the spoon's movement in normal controls will be frequently interrupted by the presence of sweat on the skin. The spoon test is inexpensive, easy to perform, but subjective and not quantitative.
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.