prohibited list raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-01-14. Anything still debated is marked as such rather than presented as settled.
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.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or oxidised impurities. Mass spectrometry, most often coupled to liquid chromatography, confirms molecular mass and detects substitutions that chromatography alone may miss. Amino acid analysis and peptide mapping supply additional structural evidence, while nuclear magnetic resonance is reserved for full structural confirmation. Laboratories that examine samples sold online report wide variation in actual content, with some vials containing little or none of the labelled material.
Melanotan-2 appears on the World Anti-Doping Agency prohibited list within the peptide hormone class, and several national regulators treat it as an unapproved prescription substance. Some countries restrict importation or sale for personal use. Because the compound is widely traded as a research chemical, the practical legal picture differs between jurisdictions and shifts over time. Human safety data covering long periods are limited, and whether repeated pigmentation changes carry any lasting risk to melanocytes remains an open question.
Freeze-dried melanotan-2 is normally kept as a desiccated powder at minus twenty degrees Celsius or lower, shielded from light and moisture. Peptides of this size degrade through hydrolysis, oxidation and deamidation, and each pathway accelerates as temperature and water activity rise. Repeated freeze-thaw cycles promote aggregation and loss of material, so aliquoting a stock solution before freezing is standard laboratory practice. Once dissolved, the solution is markedly less stable than the powder. In laboratory work, solutions are generally refrigerated and used within days rather than kept for months.
| 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 |
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.
Solid peptide kept dry at minus twenty degrees Celsius, shielded from light and moisture, is generally considered stable for extended periods. Solutions are divided into single-use aliquots and held at minus twenty or minus eighty degrees Celsius, because repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. Hydrolysis of the backbone and oxidation of tryptophan are the principal degradation routes in aqueous solution, and both accelerate at ambient temperature. Hygroscopic uptake after a vial is opened can also shift the actual mass weighed, which affects any concentration calculated from it.
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.
== Effects == CJC-1295 may markedly increase plasma growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels in animals and humans. With a single injection, in human subjects, CJC-1295 DAC may increase plasma GH levels by 2- to 10-fold for 6 days or longer and plasma IGF-1 levels by 0.5- to 3-fold for 9 to 11 days. With the inclusion of the DAC additive, the drug has an estimated half-life of about 6 to 8 days in humans. With multiple doses of CJC-1295, IGF-1 levels were found to remain elevated in humans for up to 28 days. CJC-1295 has been shown to extend the half-life and bioavailability of growth-hormone-releasing hormone 1-29 and stimulate insulin-like growth factor 1 secretion. It increases the half-life of acting agents by bioconjugation. The extended half-life is achieved through the addition of a drug affinity complex (DAC) that binds to albumin, thus prolonging the peptide's presence in the bloodstream. It is primarily used for its potential to stimulate the release of growth hormone (GH) from the pituitary gland.
=== Variability in phenotype and modifying genes === Some affected animals may remain subclinical, others may have mild signs that do not impede athletic performance, while some horses will have clinical signs that prevent any forced exercise. Rarely, horses will die from acute episodes of rhabdomyolysis. The reason for such variability of phenotype is not fully understood. Temperament, sex, and body type have no effect on degree of clinical signs. However, environmental factors such as diet and exercise, whether the horse is heterozygous or homozygous for the mutated GSY1 allele, and the presence of modifying genes all play a role. Additionally, some affected horses may have PSSM Type 2, which will produce different cellular changes and subsequently different phenotypic effects. One such modifying genes is RYR1, which is responsible for calcium regulation in muscle cells. RYR1 mutation causes malignant hyperthermia, a rare but potentially fatal disorder usually associated with anesthesia. While RYR1 mutation is rare in horses, including the general Quarter Horse population, it is much more common in Quarter Horses with GSY1 mutation. Horses with both mutations are more likely to have a severe PSSM phenotype, including higher levels of blood creatine kinase (CK), more severe exercise intolerance, more severe episodes of rhabdomyolysis (more frequent muscle fasciculations, more frequent episodes that are not associated with exercise, acute death), and poor response to PSSM treatment.
TFEU art 248 says the president may reshuffle commissioners, though this is uncommon, without member state approval. A proposal that the commissioners be drawn from the elected Parliament, was not adopted in the Treaty of Lisbon, though in practice several invariable are, relinquishing their seat in order to serve. Commissioners have various privileges, such as being exempt from member state taxes (but not EU taxes), and having immunity from prosecution for doing official acts. Commissioners have sometimes been found to have abused their offices, particularly since the Santer Commission was censured by Parliament in 1999, and it eventually resigned due to corruption allegations. This resulted in one main case, Commission v Edith Cresson where the European Court of Justice held that a Commissioner giving her dentist a job, for which he was clearly unqualified, did in fact not break any law. By contrast to the ECJ's strictly legalistic approach, a Committee of Independent Experts found that a culture had developed where few Commissioners had 'even the slightest sense of responsibility'. This led to the creation of the European Anti-fraud Office. In 2012, it investigated the Maltese Commissioner for Health, John Dalli, who quickly resigned after allegations that he received a €60m bribe in connection with a Tobacco Products Directive. Beyond the commission, the European Central Bank has relative executive autonomy in its conduct of monetary policy for the purpose of managing the euro.
New York artist Sophia Wallace started work in 2012 on a multimedia project to challenge misconceptions about the clitoris. Based on O'Connell's 1998 research, Wallace's work emphasizes the sheer scope and size of the human clitoris. She says that ignorance of this still seems to be pervasive in modern society. "It is a curious dilemma to observe the paradox that on the one hand, the female body is the primary metaphor for sexuality, its use saturates advertising, art, and the mainstream erotic imaginary", she said. "Yet, the clitoris, the true female sexual organ, is virtually invisible". The project is called Cliteracy and it includes a "clit rodeo", which is interactive, climb-on model of a giant golden clitoris, including its inner parts, produced with the help of sculptor Kenneth Thomas. "It's been a showstopper wherever it's been shown. People are hungry to be able to talk about this", Wallace said. "I love seeing men standing up for the clit [...] Cliteracy is about not having one's body controlled or legislated [...] Not having access to the pleasure that is your birthright is a deeply political act". Another project started in New York, in 2016, street art that has since spread to almost 100 cities: Clitorosity, a "community-driven effort to celebrate the full structure of the clitoris", combining chalk drawings and words to spark interaction and conversation with passers-by, which the team documents on social media. In 2016, Lori-Malépart Traversy made an animated documentary about the unrecognized anatomy of the clitoris.
Sources: en.wikipedia.org
== Career == Macor began his industrial career at Pfizer in 1986, where he was a co-inventor of eletriptan, a triptan marketed as Relpax for the acute treatment of migraine. Eletriptan was approved by the FDA in 2002. He later joined Bristol-Myers Squibb in 1997, where he served as executive director of neuroscience chemistry. At Bristol-Myers Squibb, he was a co-inventor in the program that produced the CGRP receptor antagonists rimegepant and zavegepant, which were subsequently developed by Biohaven Pharmaceuticals and approved by the FDA in 2020 and 2023, respectively, for the treatment of migraine. He is also a co-inventor of sparsentan, a dual endothelin and angiotensin II receptor antagonist developed by Travere Therapeutics and approved by the FDA in 2023 for the reduction of proteinuria in adults with IgA nephropathy. Macor’s work at Bristol-Myers Squibb also included the company’s Alzheimer’s disease program, where he contributed to the discovery of avagacestat (BMS-708163), a γ-secretase inhibitor that advanced to Phase 2 clinical trials before development was discontinued. Macor is an author on more than 220 peer-reviewed publications and a named inventor on 150 issued U.S. patents.
The system draws water from below into the material. The water diffuses into the higher layer, where it evaporates, leaving behind any contaminants. The vapor condenses on top, where it can be captured. The film is produced by repeatedly adding a fluid coating that hardens. Bacteria produce nanocellulose fibers with interspersed graphene oxide flakes. The film is light and easily manufactured at scale.
== Further reading == Mishra, NK; Agarwal, S; Raghava, GP (July 2010). "Prediction of cytochrome P450 isoform responsible for metabolizing a drug molecule". BMC Pharmacology. 10: 8. doi:10.1186/1471-2210-10-8. PMC 2912882. PMID 20637097.
Heavy experimental and avant-garde acts like the Dillinger Escape Plan, Neurosis, Zeni Geva, Ancestors, and Oranssi Pazuzu all cite King Crimson's influence. Other artists affected by King Crimson include video game composer Nobuo Uematsu, noise music artist Masami Akita of Merzbow, jazz guitarist Dennis Rea of Land, folktronica exponent Juana Molina, hip hop producer RJD2, hip hop and soul composer Adrian Younge, film director Hal Hartley, and folk-pop singer Ian Kelly. Golden Wind, the fifth part of the Japanese manga and anime franchise JoJo's Bizarre Adventure, has its main antagonist Diavolo possess a Stand known as King Crimson. Stephen King's The Dark Tower also has its main antagonist, the Crimson King, named after the band.
The representation of various sects in the Syrian parliament has evolved over time, influenced by both formal allocations and informal practices. The 1930 constitution mandated fair representation for religious minorities in both parliament and top government positions, similar to Lebanon's current confessional allocation system. This allocation continued until 1949, when it was abolished by Husni al-Za'im. The 1950 constitution further eliminated sectarian seat allocations, though it maintained reserved seats for non-Muslims, such as Christians and Jews who had at least one representative in the 1920s, as well as for nomadic Bedouins. Notably, seats designated for Bedouins were filled by tribal leaders rather than through elections. Syrian Yazidis, which number around 13,000 people at the time, were entirely excluded from parliamentary representation as the Syrian state did not recognize their faith, classifying them as Sunni Muslims. Furthermore, Kurdish political representation in Syria was limited due to the denial of citizenship to many Kurds, particularly following the 1962 census. Under Ba'athist rule from 1971 until 2024, the Ba'ath Party dominated the political landscape. While the 1973 constitution did not specify sectarian quotas, the Ba'athist-led regime maintained a balance to ensure representation of key groups.
Sources: en.wikipedia.org
Vitamin K: CID 5280483 from PubChem Vitamin K1 (phylloquinone, phytomenadione): CID 5284607 from PubChem Vitamin K2 (menaquinone 6): CID 5283547 from PubChem Vitamin K3 (menadione): CID 4055 from PubChem
The acyl azide of a peptide (1) undergoes a Curtius rearrangement in the presence of benzyl alcohol and heat(2) to give a benzyl carbamate (3). The Cbz group of intermediate 3 is removed by hydrogenolysis to give an unsubstituted amide (4) and an aldehyde (5).
X-rays can be passed through the body and used in medical radiography and fluoroscopy to differentiate interior structures that have varying degrees of opaqueness. Magnetic resonance imaging, computed tomography, and ultrasound imaging have all enabled the examination of internal structures in unprecedented detail to a degree far beyond the imagination of earlier generations. Infrared and ultraviolet analysis, computer image processing, fractal analysis, metrological analysis using image analysis methods are modern methods useful especially in neuroanatomical research.
=== Size, race, and ethnicity === Alleged differences in races have led to the creation of sexual myths. There is no scientific background to support the alleged "oversized" penis in black people. There is no indication that penis size differs between ethnicities. According to urologist Aaron Spitz, many websites and studies promoting variation of penis size between races use unscientific methods of collecting information and often ignore contradictory evidence. He concludes that "when you really take a good look at the naked data, there's not a whole lot there [showing racial variation in penis size]." A 2024 meta-analysis of 34,060 Chinese men found that while flaccid penis length was shorter on average than the global reference population, erect length showed no statistically significant difference. The study found that Chinese men had a higher average increase from flaccid to erect state (67%) compared to the global average (43%), meaning a greater proportion fell into the category colloquially known as "growers" rather than "showers." The authors noted this has implications for older cross-population studies, many of which relied on flaccid rather than erect measurements: populations with more "growers" would appear smaller in flaccid-based datasets even when erect dimensions are comparable. While some meta-analyses have identified modest average differences across geographic regions, the variation in penis size within any racial or ethnic group vastly exceeds the differences between groups.
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.
The lyophilised solid is best kept cold, dry and dark, typically at minus twenty degrees Celsius. Moisture and repeated warming cycles are the main causes of degradation. Solutions prepared from the powder are less stable and are normally used quickly.