alpha-MSH comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-09-05. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Melanotan II binds several melanocortin receptor subtypes rather than a single target. MC1R on melanocytes drives melanin synthesis, while MC3R and MC4R participate in energy balance, appetite, and sexual response pathways. This lack of selectivity explains why reported effects extend beyond skin darkening. Substitutions at positions four and seven, including norleucine and D-phenylalanine, increase potency and resistance to peptidases. Understanding which receptor mediates which effect remains an active area of investigation.
Published human data come mostly from small, short studies rather than large controlled trials. Reported outcomes include increased skin pigmentation and, in some reports, effects on appetite and libido, but sample sizes are small and follow-up is limited. Whether long-term use produces durable pigment changes or adverse effects is not established. Because products sold outside pharmacies are not standardized, the actual content of any given vial is often unknown. Independent testing of such material is uncommon.
| Property | Value | Notes |
|---|---|---|
| Compound class | Synthetic cyclic heptapeptide | Alpha-MSH analogue containing a D-phenylalanine residue |
| Molecular formula | C50H69N15O9 | Average molecular mass approximately 1024.2 g/mol |
| Appearance | White to off-white lyophilised powder | Normally supplied as a freeze-dried solid in a sealed vial |
| Solubility | Freely soluble in water and polar solvents | Dissolves readily in aqueous buffers and in alcohol-water mixtures |
| Receptor targets | MC1R, MC3R, MC4R, MC5R | Acts as a non-selective melanocortin receptor agonist |
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.
Melanotan-2 is a synthetic cyclic heptapeptide designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous tridecapeptide that regulates pigment production. Two modifications distinguish it from the natural hormone: norleucine replaces methionine at the N-terminus, which limits oxidation, and a D-phenylalanine substitution raises receptor affinity. The ring is closed through an aspartate-lysine lactam bridge, giving the molecule a constrained conformation. The free base has a molecular mass near 1024 daltons, and commercial material is usually supplied as an acetate salt. It appears in the literature as a research peptide rather than an approved therapeutic agent.
Two structural changes distinguish the synthetic peptide from the natural hormone. A norleucine residue replaces methionine at one position, and a D-configured phenylalanine replaces the natural L-form at another. Both substitutions slow enzymatic breakdown, which extends the molecule's persistence relative to the parent hormone. The lactam bridge further constrains the backbone into a stable conformation. These features are standard design strategies in peptide chemistry and are not unique to this compound; they appear across many research peptides built for improved stability.
The compound was developed in the late 1980s and early 1990s by academic researchers investigating melanocortin signaling and pigmentation. Early work explored whether synthetic analogs could reproduce effects of the natural hormone under controlled conditions. The molecule never advanced through the full regulatory pathway required for approval as a medicine. From the mid-2000s onward it appeared in unregulated consumer markets, often distributed through informal channels. That gap between research origins and commercial availability shapes how the compound is discussed today.
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.
Receptor-binding studies classify melanotan II as a non-selective melanocortin agonist. It interacts with MC1R, MC3R, MC4R and MC5R, with reported affinities in the low nanomolar range and no strong subtype preference. Activation of MC1R on dermal melanocytes shifts pigment synthesis toward eumelanin, the dark polymer deposited in melanosomes and transferred to keratinocytes. Because the same peptide engages MC4R in the hypothalamus, it also appears in animal work on food intake and erectile response, which is why it is discussed in both pigment and metabolic research. Which receptor populations dominate after systemic exposure in humans is not fully established.
Activity is attributed to agonism at melanocortin receptors, particularly MC1R and MC4R. Activation of MC1R on melanocytes increases melanin synthesis, which underlies the reported tanning effect. MC4R engagement in the central nervous system is linked to appetite suppression and to effects on sexual arousal reported in early clinical studies. Those studies were small and were not designed to establish efficacy or long-term safety. Receptor selectivity among the melanocortin subtypes is not absolute, which complicates attribution of any effect to a single pathway.
Regulatory treatment varies between countries. Several national medicines agencies have classified the peptide as unapproved, and customs authorities in some jurisdictions seize shipments on that basis. A few jurisdictions channel supply through prescription-only frameworks that do not list the substance by name. Because the material circulates mainly through online vendors, composition and purity are rarely verified before sale. Surveys of unapproved peptide products have reported labels that did not match measured content in a substantial fraction of samples.
Melanotan II is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its structure substitutes a lactam bridge between side chains to increase stability relative to the native hormone. The compound is also known by the shorthand MT-II and by several non-proprietary synonyms used in research catalogues. It is not an approved therapeutic product in any major jurisdiction; material sold under this name is typically offered as a laboratory reagent rather than as a medicine.
=== Pancreatic === Although most of the glucokinase in the body is in the liver, smaller amounts in the beta and alpha cells of the pancreas, certain hypothalamic neurons, and specific cells (enterocytes) of the gut play an increasingly appreciated role in regulation of carbohydrate metabolism. In the context of glucokinase function, these cell types are collectively referred to as neuroendocrine tissues, and they share some aspects of glucokinase regulation and function, especially the common neuroendocrine promoter. Of the neuroendocrine cells, the beta cells of the pancreatic islets are the most-studied and best-understood. It is likely that many of the regulatory relationships discovered in the beta cells will also exist in the other neuroendocrine tissues with glucokinase.
A group of Liberal MPs led by Sir John Simon opposed the Liberal Party's support for the minority Labour government. They preferred to reach an accommodation with the Conservatives. In 1931 MacDonald's Labour government fell apart in response to the Great Depression. Macdonald agreed to lead a National Government of all parties, which passed a budget to deal with the financial crisis. When few Labour MPs backed the National government, it became clear that the Conservatives had the clear majority of government supporters. They then forced MacDonald to call a general election. Lloyd George called for the party to leave the National Government but only a few MPs and candidates followed. The majority, led by Sir Herbert Samuel, decided to contest the elections as part of the government. The bulk of Liberal MPs supported the government – the Liberal Nationals (officially the "National Liberals" after 1947) led by Simon, also known as "Simonites", and the "Samuelites" or "official Liberals", led by Samuel who remained as the official party. Both groups secured about 34 MPs but proceeded to diverge even further after the election, with the Liberal Nationals remaining supporters of the government throughout its life. There were to be a succession of discussions about them rejoining the Liberals, but these usually foundered on the issues of free trade and continued support for the National Government. The one significant reunification came in 1946 when the Liberal and Liberal National party organisations in London merged.
Oxidation and reduction reactions are not common in organic chemistry as few organic molecules can act as oxidizing or reducing agents. Iron(II), on the other hand, can easily be oxidized to iron(III). This functionality is used in cytochromes, which function as electron-transfer vectors. The presence of the metal ion allows metalloenzymes to perform functions such as redox reactions that cannot easily be performed by the limited set of functional groups found in amino acids. The iron atom in most cytochromes is contained in a heme group. The differences between those cytochromes lies in the different side-chains. For instance cytochrome a has a heme a prosthetic group and cytochrome b has a heme b prosthetic group. These differences result in different Fe2+/Fe3+ redox potentials such that various cytochromes are involved in the mitochondrial electron transport chain. Cytochrome P450 enzymes perform the function of inserting an oxygen atom into a C−H bond, an oxidation reaction.
After the federation was dissolved in December 1963, British Prime Minister Sir Alec Douglas-Home insisted that preconditions on independence talks hinge on what he termed the "five principles" – unimpeded progress to majority rule, assurance against any future legislation decidedly detrimental to black interests, "improvement in the political status" of local Africans, an end to official racial discrimination, and a political settlement that could be "acceptable to the whole population". Harold Wilson and his incoming Labour government took an even harder line on demanding that these points be legitimately addressed before a timetable for independence could be set. In 1964, growing white dissatisfaction with the ongoing negotiations played a major role in the ousting of Winston Field as Prime Minister of Southern Rhodesia. Field was succeeded by Ian Smith, chairman of the conservative Rhodesian Front Party and an outspoken critic of any immediate transition to majority rule. Smith, the colony's first Rhodesian-born leader, soon came to personify resistance to liberals in British government and those agitating for change at home. In September 1964, Smith visited Lisbon, where Portuguese prime minister António de Oliveira Salazar promised him "maximum support" if he should declare independence. Aside from a common interest in maintaining security ties in southern Africa, Salazar expressed a great deal of anger at Britain's refusal to support Portugal during the Indian annexation of Goa in 1961, admonishing Smith not to trust the British government.
Sources: en.wikipedia.org
== External links == Attorney General Ellison files lawsuit against COVID-19 testing sites, lab for deceiving consumers, Minnesota Attorney General, January 19, 2022 Complaint in State of Minnesota, by its Attorney General, Keith Ellison v. Center for COVID Control, LLC and Doctors Clinical Laboratory, Inc., filed in Hennepin County District Court on January 19, 2022, file # 27-CV-22-731
== American football scandals == Boat Party (2005) – a sex party involving several members of the Minnesota Vikings of the National Football League (NFL) National Football League player conduct controversy (2007–present) – various off the field incidents involving American football athletes from the NFL, including Adam "Pacman" Jones, Terry "Tank" Johnson, Chris Henry, Ben Roethlisberger, Ray Rice, Deshaun Watson, and Adrian Peterson, who earned suspensions as a result. 2007 New England Patriots videotaping controversy (2007) – the New England Patriots were disciplined for videotaping the opposing team's coach's signals. Coach Bill Belichick was fined $500,000 and the New England Patriots were fined $250,000 and lost their 2008 1st-round draft pick. New Orleans Saints bounty scandal (2012) – the NFL discovered that the New Orleans Saints had operated a secret slush fund from 2009 to 2011 that paid "bounties" to defensive players for big plays during games, most controversially for injuring opponents. The scheme was allegedly organized by a number of players plus defensive coordinator Gregg Williams, with the acquiescence of head coach Sean Payton. Shortly after the investigation came to light, Williams was accused of running similar schemes while he was defensive coordinator of the Houston Oilers/Tennessee Titans and Washington Redskins, as well as the head coach of the Buffalo Bills. The league suspended Williams indefinitely and Payton for one year and suspended the Saints' general manager and another assistant for parts of the 2012 season.
=== Pharmacodynamics === Oxymetazoline is a sympathomimetic that selectively agonizes α1 and, partially, α2 adrenergic receptors. Since vascular beds widely express α1 receptors, the action of oxymetazoline results in vasoconstriction. In addition, the local application of the drug also results in vasoconstriction due to its action on endothelial postsynaptic α2 receptors; systemic application of α2 agonists, in contrast, causes vasodilation because of centrally-mediated inhibition of sympathetic tone via presynaptic α2 receptors. Vasoconstriction of vessels results in relief of nasal congestion in two ways: first, it increases the diameter of the airway lumen; second, it reduces fluid exudation from postcapillary venules. It can reduce nasal airway resistance (NAR) up to 35.7% and reduce nasal mucosal blood flow up to 50%. When used for treating acquired blepharoptosis, oxymetazoline is believed to work by stimulating the α1 and α2 adrenergic receptors of Müller's muscle, which helps to lift the eyelid and improve vision.
To expose the sensory tube feet and the eyespot to external stimuli, some starfish turn up the tips of their arms while moving. Having descended from bilateral organisms, starfish may move in a bilateral fashion, particularly when hunting or threatened. When crawling, certain arms act as the leading arms, while others trail behind. When a starfish finds itself upside down, two adjacent arms and an opposite arm press against the ground to lift up the two remaining arms; the opposite arm leaves the ground as the starfish turns over and recovers its normal stance. Apart from their function in locomotion, the tube feet act as accessory gills. The water vascular system serves to transport oxygen from, and carbon dioxide to, the tube feet and nutrients from the gut to the muscles involved in locomotion. Fluid movement is bidirectional and initiated by cilia.
== Preparation == Imidazole was first reported in 1858 by the German chemist Heinrich Debus, although various imidazole derivatives had been discovered as early as the 1840s. It was shown that glyoxal, formaldehyde, and ammonia condense to form imidazole (glyoxaline, as it was originally named). This synthesis, while producing relatively low yields, is still used for generating C-substituted imidazoles.
Sources: en.wikipedia.org
No. It is a laboratory-made peptide, while the natural hormone is alpha-melanocyte-stimulating hormone, a longer peptide produced by the pituitary gland and by skin cells. Melanotan-2 mimics only a short active region of that hormone and contains non-natural residues such as D-phenylalanine.
No approved regulatory indication exists in major markets. An approval exists for a different peptide, afamelanotide, which is used for a rare photosensitivity disorder called erythropoietic protoporphyria. Melanotan-2 itself remains a research compound with no cleared clinical role.
Melanocortin-1 receptors on melanocytes are the receptor most closely linked to pigment production. The peptide is not selective, however, and also activates melanocortin-3, melanocortin-4, and melanocortin-5 receptors. That lack of selectivity is the usual explanation offered for both its range of observed effects and its off-target effects.
No regulator in a major market has approved it for human use. It appears in research settings and in products marketed outside pharmacy channels. Legal status for personal possession varies by country.