alpha-MSH analogue is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-02-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Belongs to the melanocortin agonist family |
| Key substitutions | Nle4 and D-Phe7 | Improve resistance to enzymatic degradation |
| Molecular formula | C50H69N15O9 | Approximately 1024 g/mol |
| Regulatory status | Not approved as a medicine | Distributed as a research chemical |
| Common synonyms | Melanotan II, MT-II, MT-2 | Spelling varies across sources |
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.
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.
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.
Deaths are rare and occur in less than 10% of all untreated cases (usually in 2–4 days from complications following blood volume deficit and a disseminated intravascular coagulopathy), although some reports show that very severe envenomations have a 52% mortality rate. Most fatalities are associated with bad clinical management and neglect.
Before the war, education in the Gaza Strip was seen as a point of pride and a high priority. More than 95% of the children aged between 6-12 were attending school, with the majority graduating from high school. In December 2023, Jonathan Crick, a spokesperson for UNICEF in Jerusalem stated that there is absolutely no form of education or schooling in the Gaza Strip, and the about 625,000 school age children in the Strip are being deprived of an education due to war. In January 2024, the United Nations reported that children in Gaza would lose at least one year of education due to the war. According to the Palestinian Ministry of Education, the war has caused the death of about 4,327 students and injured about 7, 819 others by January 2024. Additionally at least 200 teachers have been killed and more than 500 injured by December 2023 with the number increasing to 231 teachers and administrators killed and 756 wounded by January 2024. Schools were closed at the start of the war, and underwent sustained bombing by the Israeli military, while others, such as the Israa University, were occupied and then destroyed by the Israeli military. By mid-December 2023 about 352 school buildings had been damaged, which is over 70% of the Strip's education infrastructure, with others being utilized to hold evacuated individuals and interiors utilized for fuel and survival. Some teachers attempted to continue lessons as they could, in courtyards and other areas not utilized by evacuated populations, with one teacher calling it an act of defiance and a small return to normal.
==== Pé de Meia ==== On 16 January 2024, Lula sanctioned the Pé de Meia programme, which provides the payment of a monthly financial incentive to high school students, encouraging them to continue studying until completing basic education. The programme aims to contain school evasion or dropouts, which had doubled during the pandemic, and will target students from low-income families registered in CadÚnico, with a per capita family income of up to 218 reais per month. Coming into effect on 26 January 2024, the value of the programme was R$2,000 annually, R$200 upon registration, plus 9 payments of R$200 per school month. In December 2024, the Brazilian Federal Court of Accounts asked for the programme to be blocked after an audit found that the programme was not financially viable.
Sources: en.wikipedia.org
== Limitations == Because the Edman degradation proceeds from the N-terminus of the protein, it will not work if the N-terminus has been chemically modified (e.g. by acetylation or formation of pyroglutamic acid). Sequencing will stop if a non-α-amino acid is encountered (e.g. isoaspartic acid), since the favored five-membered ring intermediate is unable to be formed. Edman degradation is generally not useful to determine the positions of disulfide bridges. Protein sequencing of attomole level of Edman degraded sequences are obtainable but require accelerator mass spectrometery which requires large, complex, and expensive equipment as well as 30 hours of bench time to analyze a single run.
In actual practice, the P-51 escorts proved both impractical and unnecessary, and only ten such missions were flown from Iwo Jima. The actual threat to American bombers from Japanese interceptor fighters continued to diminish, as all that remained in the Japanese inventory were mostly obsolescent types, exacerbated by numerous quality control issues and fuel shortages as well as insufficient pilot training, and soon the Japanese were saving their remaining planes and fuel for kamikazes. By the time Iwo Jima had been captured, the bombing campaign against Japan had switched from daylight precision bombing to nighttime incendiary attacks, so fighter escorts were of limited utility. The command's last major raid of May was a daylight incendiary attack on Yokohama on 29 May conducted by 517 B-29s escorted by 101 P-51s. This force was intercepted by 150 A6M Zero fighters, sparking an intense air battle in which five B-29s were shot down and another 175 damaged. In return, the P-51 pilots claimed 26 "kills" and 23 "probables" for the loss of three fighters. The 454 B-29s that reached Yokohama struck the city's main business district and destroyed 6.9 square miles (18 km2) of buildings; over 1000 Japanese were killed. Overall, the attacks in May destroyed 94 square miles (240 km2) of buildings, which was equivalent to one-seventh of Japan's total urban area. The minister of home affairs, Iwao Yamazaki, concluded after these raids that Japan's civil defense arrangements were "considered to be futile".
Adsorption removes a soluble impurity from a feed stream by trapping it on the surface of a solid material, such as activated carbon, that forms strong non-covalent chemical bonds with the impurity. Chromatography employs continuous adsorption and desorption on a packed bed of a solid to purify multiple components of a single feed stream. In a laboratory setting, mixture of dissolved materials are typically fed using a solvent into a column packed with an appropriate adsorbent, and due to different affinities for solvent (moving phase) versus adsorbent (stationary phase) the components in the original mixture pass through the column in the moving phase at different rates, which thus allows to selectively collect desired materials out of the initial mixture. Smelting produces metals from raw ore, and involves adding chemicals to the ore and heating it up to the melting point of the metal. Refining is used primarily in the petroleum industry, whereby crude oil is heated and separated into stages according to the condensation points of the various elements. Distillation, widely used in petroleum refining and in purification of ethanol separates volatile liquids on the basis of their relative volatilities. There are several type of distillation: simple distillation, steam distillation etc. Water purification combines a number of methods to produce potable or drinking water.
Sources: en.wikipedia.org
Deep fascia (or investing fascia) is a fascia, a layer of dense connective tissue that can surround individual muscles and groups of muscles to separate into fascial compartments. This fibrous connective tissue interpenetrates and surrounds the muscles, bones, nerves, and blood vessels of the body. It provides connection and communication in the form of aponeuroses, ligaments, tendons, retinacula, joint capsules, and septa. The deep fasciae envelop all bone (periosteum and endosteum); cartilage (perichondrium), and blood vessels (tunica externa) and become specialized in muscles (epimysium, perimysium, and endomysium) and nerves (epineurium, perineurium, and endoneurium). The high density of collagen fibers gives the deep fascia its strength and integrity. The amount of elastin fiber determines how much extensibility and resilience it will have.
Stanozolol and other synthetic steroids were first banned by the International Olympic Committee and the International Association of Athletics Federations in 1974, after methods to detect them had been developed. There are many known cases of doping in sports with stanozolol by professional athletes. Stanozolol is especially widely used by the athletes from post-Soviet countries. As of 2015, it is banned by World Anti-Doping Agency and United States Anti-Doping Agency.
30 May to 1 July Operation Lavarack was a reconnaissance in force conducted by the 6th Battalion, Royal Australian Regiment/Royal New Zealand Infantry Regiment (ANZAC) north of Nui Dat. The operation resulted in 102 PAVN/VC and 3 ANZACs killed.
Sources: en.wikipedia.org
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.
No regulatory agency has approved it for any indication. It is encountered as a research chemical sold outside pharmaceutical supply chains. Products marketed this way are not subject to the manufacturing and labeling requirements that apply to approved drugs.
Reports describe increased skin pigmentation as well as side effects such as nausea, flushing, and changes to existing moles. Much of the evidence comes from small studies and case reports rather than large trials. The long-term safety profile is therefore uncertain.
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.