The short version of melanocortin receptor fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-08-01. Anything still debated is marked as such rather than presented as settled.
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.
Outside regulated medicine, melanotan II circulates through online vendors as a research chemical, often marketed for tanning. Products sold this way vary widely in purity, concentration, and labeling accuracy, and independent testing has documented discrepancies. Published reports describe both pigment effects and adverse reactions, including nausea, flushing, and darkening of existing moles. Long-term safety data are sparse, and no large controlled trial has established a risk profile. Questions about cumulative effects on melanocytes remain unresolved in the literature.
Melanotan II is a synthetic peptide analog modeled on alpha-melanocyte-stimulating hormone, a naturally occurring signaling peptide involved in pigmentation. Its structure is a cyclic heptapeptide containing two non-natural substitutions, norleucine at position four and D-phenylalanine at position seven. These modifications resist enzymatic breakdown and extend the molecule's activity relative to the native hormone. The compound binds melanocortin receptors and is studied mainly as a pharmacological tool rather than a therapeutic product. It has never received approval as a medicine in any major jurisdiction.
The compound was developed in the late 1980s and 1990s by academic researchers investigating photoprotection. The rationale held that stimulating melanin production might reduce ultraviolet damage to skin and lower skin cancer risk. Early work examined receptor binding, pigment response, and short-term tolerability in small studies. That program did not produce an approved drug, and formal development stalled after early-phase trials. Whether induced pigmentation confers meaningful photoprotection remains an open question.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Cyclic heptapeptide, C-terminally amidated |
| Approximate molecular mass | 1024 Da | Monoisotopic mass of the free peptide |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility class | Soluble in water and polar solvents | Also dissolves in neutral aqueous buffer |
| Common synonyms | Melanotan II, MT-II, MT-2 | Described as a melanocortin agonist in early literature |
Melanocytes are the pigment-producing cells of the skin, and they carry melanocortin-1 receptors on their surface. When the receptor is activated, cyclic adenosine monophosphate rises inside the cell and raises the activity of enzymes such as tyrosinase, which increases melanin output. Melanotan-2 binds melanocortin-1 receptors in vitro and in animal models, and this binding is generally described as the basis for the tanning effect. Other receptors account for different effects: melanocortin-4 receptors contribute to appetite and erectile signalling, while melanocortin-3 and melanocortin-5 receptors contribute to energy balance and exocrine function.
Early published reports described melanotan-2 as a tanning agent without sun protection, which means darkening is not the same as protection against ultraviolet radiation. Later studies explored the peptide in erectile dysfunction, hemorrhagic shock, and some skin conditions. No regulator in the United States or Europe has approved it for clinical use. Many products labelled melanotan-2 are sold without approval and their identity and purity are unverified. Its long-term safety in humans remains an open question.
Melanotan-2, also written Melanotan II, is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, and the lactam bridge between the aspartate and lysine side chains constrains the peptide into a ring. This structural change increases receptor affinity and metabolic stability relative to the native hormone. The compound was created in the 1980s as a research tool for studying pigmentation biology.
Acifluorfen is the ISO common name for an organic compound used as an herbicide. It acts by inhibiting the enzyme protoporphyrinogen oxidase which is necessary for chlorophyll synthesis. Soybeans naturally have a high tolerance to acifluorfen and its salts, via metabolic disposal by glutathione S-transferase. It is effective against broadleaf weeds and grasses and is used agriculturally on fields growing soybeans, peanuts, peas, and rice.
Such simulations are currently able to unfold and refold small proteins (<150 amino acids residues) in equilibrium and predict how mutations affect folding kinetics and stability. In 2020 a team of researchers that used AlphaFold, an artificial intelligence (AI) protein structure prediction program developed by DeepMind placed first in CASP, a long-standing structure prediction contest. The team achieved a level of accuracy much higher than any other group. It scored above 90% for around two-thirds of the proteins in CASP's global distance test (GDT), a test that measures the degree of similarity between the structure predicted by a computational program, and the empirical structure determined experimentally in a lab. A score of 100 is considered a complete match, within the distance cutoff used for calculating GDT. AlphaFold's protein structure prediction results at CASP were described as "transformational" and "astounding". Some researchers noted that the accuracy is not high enough for a third of its predictions, and that it does not reveal the physical mechanism of protein folding for the protein folding problem to be considered solved. Nevertheless, it is considered a significant achievement in computational biology and great progress towards a decades-old grand challenge of biology, predicting the structure of proteins.
7-Eleven has a major presence in the Republic of Korea convenience store market, where it competes with CU, GS25 (formerly LG25), and independent competitors. There are 11,067 7-Eleven stores in the Republic of Korea; with only Japan and Thailand hosting more stores. The first 7-Eleven store in the Republic of Korea opened in May 1989 in Songpa-gu in Seoul with a franchise license under the Lotte Group. In January 2010, Lotte Group acquired the Buy the Way convenience store chain and rebranded its 1,000 stores under the 7-Eleven brand. In 2021, 7-Eleven announced that it would be working with a South Korean nonprofit to create jobs and franchising opportunities for North Korean defectors in South Korea. In January 2022, Lotte acquired the entire stake of Ministop Korea Co. for 313.37 billion won ($263 million). After acquisition, all the Ministop store were gradually converted to 7-Eleven.
Transport was a vital component of the country's economy. The economic centralization of the late 1920s and 1930s led to the development of infrastructure on a massive scale, most notably the establishment of Aeroflot, an aviation enterprise. The country had a wide variety of modes of transport by land, water and air. However, due to inadequate maintenance, much of the road, water and Soviet civil aviation transport were outdated and technologically backward compared to the First World. Soviet rail transport was the largest and most intensively used in the world; it was also better developed than most of its Western counterparts. By the late 1970s and early 1980s, Soviet economists were calling for the construction of more roads to alleviate some of the burdens from the railways and to improve the Soviet government budget. The street network and automotive industry remained underdeveloped, and dirt roads were common outside major cities. Soviet maintenance projects proved unable to take care of even the few roads the country had. By the early-to-mid-1980s, the Soviet authorities tried to solve the road problem by ordering the construction of new ones. Meanwhile, the automobile industry was growing at a faster rate than road construction. The underdeveloped road network led to a growing demand for public transport. Despite improvements, several aspects of the transport sector were still riddled with problems due to outdated infrastructure, lack of investment, corruption and bad decision-making.
In India, Ayurvedic medicine has quite complex formulas with 30 or more ingredients, including a sizable number of ingredients that have undergone "alchemical processing", chosen to balance dosha. In Ladakh, Lahul-Spiti, and Tibet, the Tibetan Medical System is prevalent, also called the "Amichi Medical System". Over 337 species of medicinal plants have been documented by C.P. Kala. Those are used by Amchis, the practitioners of this medical system. The Indian book, Vedas, mentions treatment of diseases with plants.
Sources: en.wikipedia.org
Lyons' Corner Houses, which first appeared in 1909 and remained until 1977, were noted for their art deco style. Situated on or near the corners of Coventry Street, Strand and Tottenham Court Road, they and the Maisons Lyons at Marble Arch and in Shaftesbury Avenue were large buildings on four or five floors, the ground floor of which was a food hall with counters for delicatessen, sweets and chocolates, cakes, fruit, flowers and other products. In addition, they possessed hairdressing salons, telephone booths, theatre booking agencies and at one period a twice-a-day food delivery service. On the other floors were several restaurants, each with a different theme and all with their own musicians. For a time the Corner Houses were open 24 hours a day, and at their peak each branch employed around 400 staff. They featured window displays, and, in the post-war period, the Corner Houses were smarter and grander than the local tea shops. The artist Kay Lipton designed all the windows for the Corner Houses under the supervision of Norman Joseph, the director post-war. Between 1896 and 1965 Lyons owned the Trocadero, which was similar in size and style to the Corner Houses.
== Genetics == Six genes have been found to be associated with the condition. These genes include BANP-ZNF469, COL4A4, FOXO1, FNDC3B, IMMP2L and RXRA-COL5A1. Others likely also exist. Patients with a parent, sibling, or child who has keratoconus have 15 to 67 times higher risk in developing corneal ectasia compared to patients with no affected relatives.
Research in mice has shown that beta cells can often regenerate to the original quantity number after the beta cells have undergone some sort of stress test, such as the intentional destruction of the beta cells in the mice subject or once the auto-immune response has concluded. While these studies have conclusive results in mice, beta cells in human subjects may not possess this same level of versatility. Investigation of beta cells following acute onset of Type 1 diabetes has shown little to no proliferation of newly synthesized beta cells, suggesting that human beta cells might not be as versatile as rat beta cells, but there is actually no comparison that can be made here because healthy (non-diabetic) rats were used to prove that beta cells can proliferate after intentional destruction of beta cells, while diseased (type-1 diabetic) humans were used in the study which was attempted to use as evidence against beta cells regenerating. It appears that much work has to be done in the field of regenerating beta cells. Just as in the discovery of creating insulin through the use of recombinant DNA, the ability to artificially create stem cells that would differentiate into beta cells would prove to be an invaluable resource to patients with Type 1 diabetes. An unlimited amount of beta cells produced artificially could potentially provide therapy to many of the patients who are affected by Type 1 diabetes.
== Treatment == Copper deficiency is a very rare disease and is often misdiagnosed several times by physicians before concluding the deficiency of copper through differential diagnosis (copper serum test and bone marrow biopsy are usually conclusive in diagnosing copper deficiency). On average, patients are diagnosed with copper deficiency around 1.1 years after their first symptoms are reported to a physician. Copper deficiency can be treated with either oral copper supplementation or intravenous copper. If zinc intoxication is present, discontinuation of zinc may be sufficient to restore copper levels to normal, but this usually is a very slow process. People with zinc intoxication will usually have to take copper supplements in addition to ceasing zinc consumption. Hematological manifestations are often quickly restored to normal. The progression of the neurological symptoms will be stopped and sometimes improved with appropriate treatment, but residual neurological disability is common.
Sources: en.wikipedia.org
== Faculty Positions == On the faculty of Indiana University, Bloomington, since 1971. 1978 – Professor of Chemistry. 1980 – Visiting Scientist, Department of Immunogenetics, Max Planck Institute for Biology, Tübingen, Germany. 1988 – James H. Rudy Professor of Chemistry. 1999 – Distinguished Professor of Chemistry. 1999 – Director of the Institute for Pheromone Research. 2000–2015 – Lilly Chemistry Alumni Chair. 2004 – Adjunct Professor of Medicine, Indiana University School of Medicine. 2004–2009 – Director of the National Center for Glycomics and Glycoproteomics. 2010 – Director of the Novotny Glycoscience Laboratory. 2011 – Distinguished Professor Emeritus of Chemistry.
A 2020 systematic review found aluminum, antimony, arsenic, cadmium, cobalt, chromium, copper, iron, lead, manganese, nickel, selenium, tin, and zinc, possibly due to coil contact. Metal parts of e-cigarettes in contact with the e-liquid can contaminate it. The temperature of the atomizer can reach up to 500 °F. The atomizer contains metals and other parts where the liquid is kept, and an atomizer head is made of a wick and metal coil which heats the liquid. Due to this design, some metals are potentially found in the e-cigarette vapor. E-cigarette devices differ in the amount of metals in the e-cigarette vapor. This may be associated with the age of various cartridges, and also what is contained in the atomizers and coils. Usage behavior may contribute to variations in the specific metals and amounts of metals found in e-cigarette vapor. An atomizer made of plastics could react with e-liquid and leach plasticizers. The amounts and kinds of metals or other materials found in the e-cigarette vapor is based on the material and other manufacturing designs of the heating element. E-cigarettes devices can be made with ceramics, plastics, rubber, filament fibers, and foams, of which some can be found in the e-cigarette vapor. E-cigarette parts, including exposed wires, wire coatings, solder joints, electrical connectors, heating element material, and vitreous fiber wick material, account for the second significant source of substances, to which users may be exposed.
Robert Fripp – guitar, keyboards, Mellotron, electronics (1968–1974, 1981–1984, 1994–2008, 2013–2021) Mel Collins – saxophones, flute, bass flute, clarinet, bass clarinet, Mellotron, backing vocals (1970–1972, 2013–2021) Tony Levin – bass guitar, Chapman Stick, upright bass, synthesisers, backing vocals (1981–1984, 1994–1999, 2003–2008, 2013–2021) Pat Mastelotto – drums, percussion, programming (1994–2008, 2013–2021) Gavin Harrison – drums, percussion (2007–2008, 2013–2021) Jakko Jakszyk – lead vocals, guitar, flute, keyboards (2013–2021) Jeremy Stacey – drums, keyboards, backing vocals (2016–2021)
Hannakins Farm mixed-use park to the north-west, includes several playing fields Mill Meadows on the eastern side of the town Norsey Wood, another nature reserve to the north-east Queens Park Country Park, also to the north-west, is managed as a local nature reserve. Norsey Wood and Mill Meadows are green wedges, in that they extend from the open countryside to the centre of town; they are environmentally valuable and sensitive, and have, in part or whole, been designated as Sites of Special Scientific Interest. Centuries of grazing have created the ideal conditions for a diversity of wild flowers, fungi, insects and invertebrates, many of which are very rare.
=== Books === Decoding Darkness: The Search for the Genetic Causes of Alzheimer's Disease. with Ann B, Parson. New York: Perseus Publishing, 2000. Super Brain: Unleashing the Explosive Power of Your Mind to Maximize Health, Happiness, and Spiritual Well-Being. New York: Harmony Books, Random House, 2012. Super Genes: Unlock the Astonishing Power of Your DNA for Optimum Health and Well-Being. New York: Harmony Books, Random House, 2015. The Healing Self: A Revolutionary New Plan to Supercharge Your Immunity and Stay Well for Life. New York: Harmony, Random House, 2018.
Sources: en.wikipedia.org
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.
Afamelanotide is the linear analogue [Nle4-D-Phe7]-alpha-MSH, sometimes called melanotan I, while melanotan II is cyclic and carries three further substitutions. The two are distinct molecules and are not interchangeable in analytical testing.
Binding to the four melanocortin receptor subtypes is well documented in vitro. The relative contribution of each subtype to whole-body effects in humans is far less certain.
It is a synthetic cyclic peptide designed as an analog of alpha-melanocyte-stimulating hormone. It acts on melanocortin receptors and is best known from research into pigmentation. It is not an approved pharmaceutical product.