Everything below concerns alpha-MSH analog. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-25. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
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.
| 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-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.
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.
=== 18 January === Forty people were killed in an RSF attack on the village of Jebel Hilla in North Darfur. Six drones struck the Al-Shawak power station in Gedaref State, injuring civil defence personnel and causing blackouts across the state and in Kassala State. Other drones hit the Gedaref state water station while another crashed near a bus station along the Gedaref-Kassala-Port Sudan highway. The SAF reached the Al-Shukri junction in Shambat, Khartoum Bahri, while the RSF retreated by one kilometer southwards to the Hassan Ibrahim Malik University City. At least three people were killed by RSF shelling in Omdurman. The RSF claimed to have taken Al-Hallaf, Drishaqi and Mao in North Darfur.
== History == The term "hydrocolloid" was coined in the 1960s during the development of mucoadhesives, first used to treat mouth ulcers. The term was later adopted for a new dressing type in which a hydrophilic gelable mass was applied to a flexible semipermeable carrier. It was first sold under the brand Granuflex in the United Kingdom in 1982, and then DuoDERM in the United States in 1983. Different products subsequently came to market with slightly varying formulations, designed for specific areas of the body or specific purposes (for example, postoperative dressings). More recently, the term has sometimes been used to describe hydrogel dressings which are fundamentally different to hydrocolloid dressings.
== Pultronics today == Today (>1998), Pultronics is involved in the RFID industry with its active RFID systems for long-range wireless data communications. Tracking of goods/assets through a cold chain is a typical usage of such systems. Pultronics is also active in the micro-transmitter system design including design of ASICs resulting in miniature sized active tags.
Sources: en.wikipedia.org
The removal of the docks to Avonmouth, seven miles (11 km) downstream from the city centre, relieved congestion in the central zone of Bristol and allowed substantial redevelopment of the old central dock area (the Floating Harbour) in the late 20th century. The deep-water Royal Portbury Dock was developed opposite Avonmouth Docks in the 1970s and following privatisation of the Port of Bristol has become financially successful. At one time the continued existence of the old central docks was in jeopardy as it was seen merely as derelict industry rather than an asset to be developed for public use. Since the 1980s millions of pounds have been spent regenerating the harbourside. 1999 saw the redevelopment of the city centre and the construction of Pero's footbridge; which now links the At-Bristol science centre at Canon's Marsh, opened in 2000, with other Bristol tourist attractions. Private investors are also constructing studio apartment buildings. The regeneration of the Canon's Marsh area is expected to cost £240 million. Crest Nicholson were the lead developers constructing 450 new flats, homes and waterside offices, under the guidance of The Harbourside Sponsors' Group which is a partnership between the City Council, developers, businesses, and public funders.
=== Statehood era === The U.S. conducted underground tests of nuclear weapons on Amchitka Island from 1965 to 1971 as part of the Vela Uniform program. The final detonation, the Cannikin, was the largest underground nuclear explosion by the U.S. The Alaska Native Claims Settlement Act became law in 1971. In 1977, the Ounalashka Corporation (from Unalaska) declared a dividend. This was the first village corporation to declare and pay a dividend to its shareholders. The Aleutian Islands were designated a UNESCO biosphere reserve in 1976. The Aleutians were one of 17 biosphere reserves in the United States withdrawn by request of the U.S. government from the programme in June 2017.
== Education == Özergin completed a B.S. (1987) and M.S. (1989) in chemical engineering at Boğaziçi University. She earned a Ph.D. in chemical engineering at University of Manchester in 1992. Özergin researched Streptomyces coelicolor antibiotic production and bioreactors. Her dissertation was titled Study of antibiotic synthesis by free and immobilised streptomyces coelicolor a3(2). Özergin's doctoral advisor was Ferda Mavituna.
Sources: en.wikipedia.org
===== Endangered species and other wild animals ===== Some compounds can include the parts of endangered species, including tiger bones and rhinoceros horn which is used for many ailments (though not as an aphrodisiac as is commonly misunderstood in the West). The black market in rhinoceros horns (driven not just by TCM but also unrelated status-seeking) has reduced the world's rhino population by more than 90 percent over the past 40 years. Concerns have also arisen over the use of pangolin scales, turtle plastron, seahorses, and the gill plates of mobula and manta rays. Poachers hunt restricted or endangered species to supply the black market with TCM products. There is no scientific evidence of efficacy for tiger medicines. Concern over China considering to legalize the trade in tiger parts prompted the 171-nation Convention on International Trade in Endangered Species (CITES) to endorse a decision opposing the resurgence of trade in tigers. Fewer than 30,000 saiga antelopes remain, the horns of which are illegally exported to China by organized gangs to be used in traditional fever therapies. The pressures on seahorses (Hippocampus spp.) used in traditional medicine is enormous; tens of millions of animals are unsustainably caught annually. Many species of syngnathid are currently part of the IUCN Red List of Threatened Species or national equivalents. The deer penis is believed to have therapeutic benefits according to traditional Chinese medicine. Tiger parts from poached animals include tiger penis, believed to improve virility, and tiger eyes.
After Constantinople fell, the Ottomans quickly absorbed the remaining independent territories, including Acciaiuoli Athens in 1458, Morea in 1460, Trebizond in 1461, and Gattilusi Lesbos in 1462. They dismantled the Empire's political and secular institutions, leaving the impoverished Church to manage what would be later called the Rum Millet, primarily as a tool for taxing its followers. As the sole sovereign Orthodox state, Russia developed the Third Rome doctrine, emphasising its cultural heritage as distinct from Western Europe, because the latter had inherited much of the empire's secular learning. The Danubian Principalities became a haven for Orthodox Christians and Phanariot Greeks who sought to recreate a Byzantine Greek Empire. In modern Greece, members of the Rum Millet increasingly identified as Greeks, eventually leading to a successful war of independence in the 19th century. The modern Greek state nearly doubled its territory through the pursuit of the Megali Idea—a vision of reclaiming the former lands of the eastern empire—achieving limited success during the Crimean War but making significant gains during the Balkan Wars. Since the 15th century, Byzantine history has been deeply politicised, woven into nationalist, colonialist, and imperialist narratives. This politicisation appears not only in Greece but also in Bulgarian, Romanian, Serbian, Hungarian, and Turkish nationalism, as well as in former French and Russian imperialist agendas.
Cathode: 3 O2 + 6 H2O + 12 e− → 12 OH− Anode: 4 Fe → 4 Fe2+ + 8 e−; 4 Fe2+ → 4 Fe3+ + 4 e− Overall: 4 Fe + 3 O2 + 6 H2O → 4 Fe3+ + 12 OH− → 4 Fe(OH)3 or 4 FeO(OH) + 4 H2O The electrolyte is usually iron(II) sulfate in urban areas (formed when atmospheric sulfur dioxide attacks iron), and salt particles in the atmosphere in seaside areas.
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. 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.