regulatory status raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-12-28. Anything still debated is marked as such rather than presented as settled.
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-2 is a synthetic peptide designed as an analog of alpha-melanocyte-stimulating hormone, a signaling molecule produced in the pituitary and skin. Its structure is a linear chain of seven amino acids that folds into a ring through an internal lactam bridge joining two side chains. The compound is sometimes written as MT-II or MEL-2 in informal and commercial contexts. It belongs to the melanocortin peptide family, a group of short signaling molecules that share a conserved core sequence recognized by melanocortin receptors.
Scientific discussion of Melanotan-2 spans pharmacology, dermatology, and public-health literature. Laboratory studies examine its receptor binding and cellular effects, while clinical reports describe outcomes observed after unregulated use. These two bodies of work differ in rigour and intent. Peer-reviewed trials of the compound as a medicine are limited, so much of the available information comes from case reports and surveillance data. Authors frequently note the gap between experimental findings and real-world use.
Reported observations after unregulated use include shifts in skin pigmentation and, in some accounts, unintended changes to moles and other lesions. Whether these outcomes are causally linked to the compound, and how often they occur, remain open questions because controlled data are scarce. The absence of standardised dosing and verified product purity complicates interpretation. Researchers have called for better surveillance and analytical characterisation of samples obtained outside regulated channels. Conclusions drawn from anecdotal evidence should be treated as provisional.
Melanotan-2 has not received marketing authorisation from major regulatory agencies for any therapeutic indication. Several jurisdictions classify it as a prescription-only medicine or a controlled substance when supplied for human use. Because approved products do not exist, material sold online usually sits outside pharmaceutical supply chains and formal quality oversight. Regulators have issued public notices describing the compound as unapproved. Enforcement varies, and the legal position differs between countries, which complicates any single general statement about its status.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic cyclic heptapeptide | Analog of alpha-MSH with an internal lactam bridge |
| Molecular weight | Approximately 1024 daltons | Free base value; salt forms differ |
| Appearance | White to off-white powder | Usually supplied as a lyophilized solid |
| Solubility | Freely soluble in water | Poorly soluble in nonpolar solvents |
| Typical storage | −20 °C, dry, protected from light | Repeated freeze-thaw cycles degrade peptides |
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.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, the naturally occurring peptide involved in pigmentation signalling. Its sequence is conventionally written as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, with a lactam bridge joining the aspartate side chain to the lysine side chain. The empirical formula is C50H69N15O9 and the monoisotopic mass lies near 1023.5 daltons. N-terminal acetylation and the D-configured phenylalanine both increase resistance to enzymatic breakdown compared with the parent hormone.
Routine characterisation relies on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, using a C18 column and a water-acetonitrile gradient containing trifluoroacetic acid. Electrospray ionisation mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidised by-products that co-elute poorly. Sequence and stereochemistry require additional work, such as peptide mapping or amino acid analysis, because a chromatographic purity figure alone does not distinguish a diastereomer from the target peptide. Independent testing of research-grade material frequently shows measured content below the stated label, so a certificate of analysis is best read together with the method that produced it.
Melanotan-2 is handled in the laboratory as a lyophilised powder that dissolves readily in water, dimethyl sulfoxide and dimethylformamide, with limited solubility in ethanol. Stock solutions prepared in an organic solvent often precipitate when diluted into aqueous buffer, so gradual dilution with mixing is standard practice. The peptide carries a tryptophan residue and a histidine residue, both sensitive to oxidation and to alkaline conditions. Working solutions are therefore kept near neutral to slightly acidic pH, protected from light, and consumed within the same working session whenever that is practical.
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.
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.
== External links == "Tyrian Purple". World History Encyclopedia. Cooksey CJ (1994). "Making Tyrian purple". Dyes in History and Archaeology. 13: 7–13 (email the author for a copy). Archived from the original on 2020-07-26. Retrieved 2010-05-11. Source of article in author's Bibliography page. Guckelsberger M (December 2013). Purple Murex Dye in Antiquity (PDF) (Thesis). University of Iceland. "Tyrian purple". The Free Library. "Royal Purple of Tyre" (PDF).
Wenger's arrival at Arsenal was greeted with perplexity by some of the club's players, supporters and the local media. Although he was touted as a future technical director of The Football Association (FA), he was relatively unknown in English football. Glenn Moore's report in The Independent, dated 24 September 1996, highlighted the mood: "It is a measure of the insularity of the English game that when Arsène Wenger's name emerged as Arsenal's favoured candidate for their vacant manager's job many supporters were asking: 'Arsène who?'" Unlike his predecessors, Wenger was given control over transfers, contracts and training sessions, and the Arsenal board chose not to meddle in team affairs. One of his first acts as manager was to assure the experienced players they had a future at the club, but he noted the squad was "a bit tight," and needed competition for places. Wenger adopted a hands-on approach to training sessions which energised the squad, and made steps to change the drinking culture that afflicted Arsenal. Although he initially allowed players to have a pint of beer, they were forbidden to drink on days off and in the players' lounge. He later banned his players from casually drinking together. Wenger also promoted pasta as the pre-match dish, encouraged boiled chicken instead of red meat and discouraged junk food. Players received optional vitamin injections and Creatine, which reduced fatigue and improved their stamina.
== Plot == In an impoverished and burnt out Tokyo ghetto of post-World War II Japan, a band of prostitutes defend their territory, squatting in a bombed-out building. Somehow they eke out a living together. Forming a sort of family in an environment where everyone (American soldiers and Japanese yakuza) is a potential antagonist, the girls cajole each other, and ruthlessly punish any of their group who violate the cardinal rule—no falling in love. A new girl, Maya (Yumiko Nogawa), joins their group and learns the trade. An ex-soldier, Shintaro Ibuki (Joe Shishido), is shot nearby and holes up with the girls. Each of them starts to crave Ibuki, placing strains on the group. Maya feels it worst, seeing him as replacement for her brother (who died in Borneo). She takes him for a night of drunken revelry, and both are ostracized. Agreeing to run away together, he is shot in a double-cross, and she is left as she was at the beginning of the film—alone and hopeless.
== External links == Rudra MN, Chowdhury LM (30 September 1950). "Methionine Content of Cereals and Legumes". Nature. 166 (568): 568. Bibcode:1950Natur.166..568R. doi:10.1038/166568a0. PMID 14780151. S2CID 3026278.
Sources: en.wikipedia.org
The properties of acids and bases are relevant to physical organic chemistry. Organic chemists are primarily concerned with Brønsted–Lowry acids/bases as proton donors/acceptors and Lewis acids/bases as electron acceptors/donors in organic reactions. Chemists use a series of factors developed from physical chemistry -- electronegativity/Induction, bond strengths, resonance, hybridization, aromaticity, and solvation—to predict relative acidities and basicities. The hard/soft acid/base principle is utilized to predict molecular interactions and reaction direction. In general, interactions between molecules of the same type are preferred. That is, hard acids will associate with hard bases, and soft acids with soft bases. The concept of hard acids and bases is often exploited in the synthesis of inorganic coordination complexes.
== Veterinary uses == In February 2025, the Committee for Veterinary Medicinal Products of the European Medicines Agency adopted a positive opinion, recommending the granting of a marketing authorization for the veterinary medicinal product Omeprazole TriviumVet, gastro-resistant capsule, hard, intended for dogs. The applicant for this veterinary medicinal product is TriviumVet DAC. Omeprazole TriviumVet was authorized for veterinary use in the European Union in April 2025.
== Death == Sun likely spent the last few years of his life as a monk, before working as a caretaker of the Guanghua temple in Beijing. He lived there until his death on 17 December 1996 at the age of 93.
Nuclear warfare and weapons are staple elements of speculative fiction. The War Game by Peter Watkins is a docudrama depicting a hypothetical nuclear attack on Britain. Fail Safe, directed by Sidney Lumet, is a 1964 Cold War techno-thriller presenting a dramatization of an unintended nuclear escalation triggered by a mechanical failure.
==== Functional or Mean Fields Model ==== The functional or mean fields model relies on the premise "simpler is better". It strives to reduce the complexity of modelling multi-faceted systems by using a single variable to describe an entire population of cells. The alternative would be to use a different set of variables for each population. When attempting to model a system where multiple populations of cells interact, using several sets quickly becomes overcomplicated. This model has been used to describe several systems, especially involving the reproductive cycle (menstrual cycles, luteinizing hormone, prolactin surges). Functional models also exist to represent cortisol secretion, and growth hormone secretion.
Sources: en.wikipedia.org
A GnRH modulator, or GnRH receptor modulator, also known as an LHRH modulator or LHRH receptor modulator, is a type of medication which modulates the GnRH receptor, the biological target of the hypothalamic hormone gonadotropin-releasing hormone (GnRH; also known as luteinizing-releasing hormone, or LHRH). They include GnRH agonists and GnRH antagonists. These medications may be GnRH analogues like leuprorelin and cetrorelix – peptides that are structurally related to GnRH – or small-molecules like elagolix and relugolix, which are structurally distinct from and unrelated to GnRH analogues. GnRH modulators affect the secretion of the gonadotropins, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), which in turn affects the gonads, influencing their function and hence fertility as well as the production of sex steroids, including that of estradiol and progesterone in women and of testosterone in men. As such, GnRH modulators can also be described as progonadotropic or antigonadotropic, depending on whether they act to increase or decrease gonadotropins. Shortly after the discovery of GnRH by Nobel laureates Guillemin and Schally, researchers tried to modify the GnRH decapeptide with the intent to create analogues that could activate or block the receptor. Subsequent to the development and introduction of GnRH analogues, non-peptide or small-molecule GnRH modulators were developed and introduced. All GnRH modulators are contraindicated in pregnancy (pregnancy category X).
Hahn joined the new gas command unit at Imperial Headquarters in Berlin in December 1916 after travelling between the western and eastern front, Berlin and Leverkusen between mid-1914 and late 1916. Most of the students, laboratory assistants and technicians had been called up, so Hahn, who was stationed in Berlin between January and September 1917, and Meitner had to do everything themselves. By December 1917 she was able to isolate the substance, and after further work were able to prove that it was indeed the missing isotope. Meitner submitted her and Hahn's findings for publication in March 1918 to the scientific paper Physikalischen Zeitschrift under the title Die Muttersubstanz des Actiniums; Ein Neues Radioaktives Element von Langer Lebensdauer ("The Mother Substance of Actinium; A New Radioactive Element with a Long Lifetime"). Although Fajans and Göhring had been the first to discover the element, custom required that an element was represented by its longest-lived and most abundant isotope, and while brevium had a half-life of 1.7 minutes, Hahn and Meitner's isotope had one of 32,500 years. The name brevium no longer seemed appropriate. Fajans agreed to Meitner and Hahn naming the element "protoactinium". In June 1918, Soddy and John Cranston announced that they had extracted a sample of the isotope, but unlike Hahn and Meitner were unable to describe its characteristics. They acknowledged Hahn´s and Meitner's priority, and agreed to the name. The connection to uranium remained a mystery, as neither of the known isotopes of uranium decayed into protactinium.
Nakamoto limited the block size to one megabyte. The limited block size and frequency can lead to delayed processing of transactions, increased fees and a bitcoin scalability problem. The Lightning Network, a second-layer routing network, is a potential scaling solution. Research shows a trend towards centralization in bitcoin as miners join pools for stable income. If a single miner or pool controls more than 50% of the hashing power, it would allow them to censor transactions and double-spend coins. In 2014, mining pool Ghash.io reached 51% mining power, causing safety concerns, but later voluntarily capped its power at 39.99% for the benefit of the whole network. A few entities also dominate other parts of the ecosystem such as the client software, online wallets, and simplified payment verification (SPV) clients.
Edward Frank Gale. For political service. Richard Gallagher. For services to the community in Aberdeen. Lucy Gannon, Writer. For services to Television Drama. Richard Ian Gardner. For services to the Police. Arthur Buchan Geddes, Sector Officer, the Coastguard Agency, Department of Transport. Arthur Samuel George, School Crossing Patrol, Portsmouth, Hampshire. For services to Road Safety. James Alexander George, Administrative Officer, Ministry of Defence. Graham James Gibb, Leader, Grampian Police and Braemar Mountain Rescue Teams. For services to Mountain Rescue. Alison Gray Gibson, Temporary Project Manager, Royal Mail, Edinburgh. For services to the Post Office. Sydney Gibson, Secretary, Fergusons Lane Tenants Association. For services to the community in Scotswood, Newcastle-upon-Tyne. Valerie Gibson. For services to the Right to Peace and Quiet Campaign. Joan Giddings, lately Office Administrator, British Apparel and Textile Confederation. For services to the Clothing Industry. Elizabeth Glasgow. For services to the community in Wester Hailes, Edinburgh. John Glover. For services to Golf. Maureen Audrey Gobbett, Higher Executive Officer, Ministry of Defence. Major Douglas George Goddard. For services to the community in Wargrave-on-Thames, Berkshire. David William Goodall. For services to Nature Conservation in Hampshire. Ian Kenmure Evans-Gordon. For political service. Stephen Goulding, Pay Band 8, the Employment Service, Department for Education and Employment. Anne Greaves. For services to the Health and Safety Commission's Occupational Health Advisory Committee.
=== Prostate conditions === Spironolactone has been studied at a high dosage in the treatment of benign prostatic hyperplasia (BPH; enlarged prostate). It was found to be better than placebo in terms of symptom relief following three months of treatment. However, this was not maintained after six months of treatment, by which point the improvements had largely disappeared. Moreover, no difference was observed between spironolactone and placebo with regard to volume of residual urine or prostate size. Gynecomastia was observed in about 5% of people. On the basis of these results, it has been said that spironolactone has no place in the treatment of BPH. Spironolactone has been studied and used limitedly in the treatment of prostate cancer.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide modeled on alpha-melanocyte-stimulating hormone. It carries two non-natural substitutions and a cyclic bridge that increase its stability relative to the natural hormone. It circulates as a research chemical and is not an approved medicine.
Melanotan-1, also called afamelanotide, is a shorter linear analog with a different amino acid sequence and no lactam ring. It has been evaluated in formal clinical programs, while melanotan-2 has not. The two are distinct molecules and are not interchangeable.
No. Bremelanotide is a related but distinct cyclic peptide that reached approved status for one specific clinical indication. Melanotan-2 is a separate molecule with its own sequence and properties. Shared ancestry in the melanocortin family does not make them the same substance.
Major regulatory agencies have not approved it for any indication. Some countries permit it only under prescription frameworks, while others classify it as a controlled substance.