afamelanotide 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 2026-01-25. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Free base; salt forms differ |
| Molecular weight | Approximately 1024 g/mol | Calculated for the free base |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water and polar solvents | Poorly soluble in non-polar solvents |
| Typical storage | -20 degrees Celsius, dry, protected from light | Refers to the solid form |
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.
Pharmacologically, melanotan-2 behaves as a non-selective agonist across the melanocortin receptor family. Binding at MC1R on dermal melanocytes promotes eumelanin synthesis, which underlies the tanning response described in early human work. Activity at the centrally expressed MC4R receptor is associated with reported effects on appetite and erectile function. Because the peptide does not discriminate strongly among receptor subtypes, attributing any single observed effect to one receptor pathway is generally not possible without selective antagonists or receptor knockout models.
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.
Lance Armstrong doping case (2012) – after having been accused of doping for much of the latter part of his career, Lance Armstrong became the subject of an investigation by the United States Anti-Doping Agency. The USADA report revealed that he had engaged in a highly sophisticated doping campaign from 1998 onward. Following the report, the UCI stripped all of Armstrong's results and awards from that time forward, including his then-record seven Tour de France wins. Biogenesis baseball scandal (2013) – more than a dozen MLB players were found to have received PEDs, mainly human growth hormone, from a now-defunct anti-aging clinic in the Miami area. In all, 13 players received suspensions of 50 or more games, with the longest being given to Alex Rodriguez (162 games) and Ryan Braun (65 games). The number of players suspended is the most for any single incident in the history of organized baseball in North America. Essendon Football Club supplements saga (2013) – in February 2013, the Essendon Football Club, a professional Australian rules football club participating in the Australian Football League (AFL), were investigated by the Australian Sports Anti-Doping Authority (ASADA) and the World Anti-Doping Agency (WADA) over the legality of its supplements program during the 2012 AFL season and the preceding preseason. In January 2016, the players were found guilty of having used the banned peptide thymosin beta-4, resulting in the suspensions of thirty-four players who were part of the program.
In late 1973, Olofsson was incarcerated at the Norrköping Prison when bank robber Jan-Erik Olsson took hostages at Kreditbanken at Norrmalmstorg, Stockholm. Olsson demanded that Olofsson be allowed to come to the bank. Olofsson was brought to the bank, where he spent the next six days with the hostages. This event subsequently led to the creation of the phrase "Stockholm syndrome". Olofsson was convicted in the district court but was later acquitted in Svea Court of Appeal. He had, according to himself, acted to protect the hostages and had the silent consent of the police. He was taken back to prison to serve the remainder of his previous sentence. He sought a pardon from the government but the application was rejected along with his request to study law.
== Publications == Eltenton, G. C. (1938). "Direct Evidence for the N2H+ Ion in the Discharge Reaction between N2 and H2". Nature. 141 (3578): 975–976. Bibcode:1938Natur.141..975E. doi:10.1038/141975b0. S2CID 4041283. Eltenton, G. C. (1942). "The Detection of Free Radicals by Means of a Mass Spectrometer". Journal of Chemical Physics. 10 (6): 403. Bibcode:1942JChPh..10..403E. doi:10.1063/1.1723738. Eltenton, G. C. (1947). "The Study of Reaction Intermediates by Means of a Mass Spectrometer Part I. Apparatus and Method". Journal of Chemical Physics. 15 (7): 455–481. Bibcode:1947JChPh..15..455E. doi:10.1063/1.1746565. Eltenton, G. C. (1954). "Some instruments for quality control in petroleum refineries". Journal of Applied Chemistry. 4 (5): 245–256. doi:10.1002/jctb.5010040503.
Concurrently to the oxygen barrier property, the permeability of water vapor through a food packaging system should be minimized to effectively prevent physical and chemical changes connected to an excessive moisture content. The moisture barrier properties of a material can be assessed by measuring the water vapor transmission rate (WVTR), which can be defined as the amount of water vapor per unit of area and unit of time passing through the packaging film. The WVTR measurements, like the OTR, adhere to the standards for standardized tests, as outlined in the ASTM E96 (standard methods for water vapor transmission of materials). An impermeable test dish (such as a stainless steel cup) and a test chamber, where temperature and relative humidity (RH) can be adjusted in accordance with the standard specification, make up the basic instrumentation used in such tests.
Sources: en.wikipedia.org
Dolor (pain) Calor (heat) Rubor (redness) of the skin Tumor (swelling) Functio laesa (loss of function) The first four (classical signs) were described by Celsus (c. 30 BC–38 AD). Pain is due to the release of chemicals such as bradykinin and histamine that stimulate nerve endings. Heat and redness are due to increased blood flow at body core temperature to the inflamed site. Swelling is caused by accumulation of fluid. The fifth sign, loss of function, is believed to have been added later by Galen, Thomas Sydenham or Rudolf Virchow. Examples of loss of function include pain that inhibits mobility, severe swelling that prevents movement, having a worse sense of smell during a cold, or having difficulty breathing when bronchitis is present. Loss of function has multiple causes. Chronic inflammation often presents symptoms such as:
Pyongan Province Non-traditional ingredients have been adopted in rural areas due to severe food shortages. Hamgyong Province: Due to its proximity to the ocean, people in this particular region use fresh fish and oysters to season their kimchi. Hwanghae Province: The taste of kimchi in Hwanghae Province is not bland but not extremely spicy. Most kimchi from this region have less color since red chili flakes are not used. The typical kimchi in Hwanghae Province is called hobakji (호박지). It is made with pumpkin (bundi). Gyeonggi Province Chungcheong Province: Instead of using fermented fish, people in the region rely on salt and fermentation to make savory kimchi. Chungcheong Province has the most varieties of kimchi. Gangwon Province, South Korea/Kangwon Province, North Korea: In Gangwon Province, kimchi is stored for longer periods. Unlike other coastal regions in Korea, kimchi in this area does not contain much salted fish. Jeolla Province: Salted yellow corvina and salted butterfish are used in this region to create different seasonings for kimchi. Gyeongsang Province: This region's cuisine is saltier and spicier. The most common seasoning components include myeolchijeot (멸치젓) which produces a briny and savory flavor. They also use oysters in their kimchi. Foreign countries: In some places of the world people sometimes make kimchi with western cabbage and many other alternative ingredients such as broccoli.
== Analysis == According to Sally Waller, part of the sans-culottes mantra was "permanent anticipation of betrayal and treachery". The members of the sans-culottes were constantly on edge and fearing betrayal, which can be attributed to their violent and radical rebellion tactics. Marxist historian Eric Hobsbawm observes that the sans-culottes were a "shapeless, mostly urban movement of the labouring poor, small craftsmen, shopkeepers, artisans, tiny entrepreneurs and the like". He further notes they were organised notably in the local political clubs of Paris and "provided the main striking-force of the revolution". Hobsbawm writes that these were the actual demonstrators, rioters and constructors of the street barricades. However, Hobsbawm maintains, sans-culottism provided no real alternative to the bourgeois radicalism of the Jacobins; from Hobsbawm's Marxist perspective, the ideal of the sans-culottes, which sought to express the interests of the "little men" who existed between the poles of the bourgeoisie and the proletariat, was contradictory and ultimately unrealizable. The Marxist historian Albert Soboul emphasized the importance of the sans-culottes as a social class, a sort of proto-proletariat that played a central role in the French Revolution. That view has been sharply attacked by scholars who say the sans-culottes were not a class at all. As one historian observes, Soboul's concept has not been used by scholars in any other period of French history.
== Plantations == Blue gum is one of the most extensively planted eucalypts. Its rapid growth and adaptability to a range of conditions is responsible for its popularity. It is especially well-suited to countries with a Mediterranean-type climate, but also grows well in high altitudes in the tropics. It comprises 65% of all plantation hardwood in Australia with approximately 4,500 km2 (1,100,000 acres) planted. In about 1860 Francis Cook planted the tree on the Monserrate Palace, his property at Sintra in Portugal. By 1878 the tree "had spread from one end of Portugal to the other". E. globulus began to be planted as plantations in Los Lagos and Los Ríos regions of Chile in the 1990s. However at these latitudes around the 40th parallel south the tree is at the southern border of the climatic conditions where it can grow, hence good growth in this part of southern Chile requires good site selection such as sunny north-facing slopes. Some of these plantations grow on red clay soil.
Buck O'Neil and the Negro Leagues Baseball Museum presented Helton with the Walter Fenner "Buck" Leonard Legacy Award. Helton was also given the team-honored version of the Roberto Clemente Award, for his community contributions to eastern Tennessee. Furthermore, he was the NL winner of the second annual Hank Aaron Award. Each season from 2000 to 2003, he was named the Rockies Player of the Year. Capitalizing on his success, Helton signed a nine-year, $141.5 million contract in April 2001, which took effect after his then-contract expired after 2002. That season, Helton hit a career-high 49 home runs (22 of them occurred away from hitter-friendly Coors Field). He tied Walker for the most home runs ever by a Rockies player in one season. Additionally, Helton had a .336/.432/.685 slash line. He had 105 extra base hits, making him the first player in MLB history to have at least 100 total extra base hits in back-to-back seasons. Furthermore, Helton attained 402 total bases, making him only the fourth player in MLB history to do so in consecutive seasons (Chuck Klein, Gehrig and Foxx are the others). Helton appeared in his second consecutive All-Star Game in 2001 — his first as a starter. He won his first Gold Glove at first base and was once again a top candidate for MVP, but was beaten in balloting by Sammy Sosa and Barry Bonds. In 2002, Helton had a .329 batting average, 30 home runs, 109 RBI, 98 walks, 107 runs, .577 SLG and 319 total bases. He became the first player in Rockies history to score at least 100 runs in four consecutive seasons.
Sources: en.wikipedia.org
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.
Both are synthetic analogues derived from the same parent hormone. Reference descriptions usually characterise afamelanotide as more selective for the MC1R subtype, whereas melanotan-2 is reported to interact with a wider range of melanocortin receptors.
Early studies explored melanocortin signalling and pigmentation, which later led to informal use of the label tanning peptide. That label is not a regulatory category and does not imply approved status for any purpose.
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.