Everything below concerns Alpha-MSH. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-01-10. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Regulatory status varies by jurisdiction, and the substance is frequently described as unapproved for therapeutic use. Some authorities classify it alongside prescription-only medicines or controlled categories, while others address it through general consumer protection rules. Analytical surveys have reported mismatches between label claims and measured content in products sold online, although the scope of such testing is limited. Whether these discrepancies are widespread remains an open question. Discussion in the literature therefore tends to combine chemistry, supply-chain observation and policy analysis.
The material is commonly handled as a lyophilized powder in sealed vials. The solid dissolves readily in water and in polar organic solvents, producing a clear solution after reconstitution. Light, heat and repeated freeze-thaw cycles are the concerns most often raised in handling guidance, because peptide bonds and the constrained ring can degrade. Working solutions are generally prepared fresh, and material left in solution is treated as less stable than the dry form. These properties shape how laboratories store and aliquot reference material.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Retention time supports identity, while the mass spectrum confirms the molecular weight of the intact peptide. Purity is frequently reported as a percentage of total peak area, a figure that depends on the wavelength, column and gradient used. Impurity profiling may also look for truncated sequences, oxidised forms and residual counterions. Amino acid analysis and peptide mapping provide orthogonal confirmation when required.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Cyclic heptapeptide, C-terminally amidated |
| Approximate molecular mass | 1024 Da | Monoisotopic mass of the free peptide |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility class | Soluble in water and polar solvents | Also dissolves in neutral aqueous buffer |
| Common synonyms | Melanotan II, MT-II, MT-2 | Described as a melanocortin agonist in early literature |
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.
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.
Regulatory treatment varies by country. In the United States the peptide is not approved as a medicine, and products offered for human use may be treated as unapproved new drugs; some states also restrict sale. Australia, the United Kingdom, and European Union member states apply comparable restrictions to unapproved peptide products. Border agencies have seized shipments labelled as research chemicals. Classification may change over time, and the legal position for personal importation is not clearly settled in most published guidance.
Lyophilised melanotan-2 is supplied as a solid, which is more stable than a solution. The material is hygroscopic, so weighing is done quickly, in low humidity, with the container kept sealed. Reconstitution usually uses water for injection or bacteriostatic water, added down the wall of the vial to limit foaming. A reconstituted solution is held at 2 to 8 °C and kept away from light. Repeated freezing and thawing of the same vial is avoided because ice crystal formation and concentration effects degrade the peptide.
Melanocortin receptors comprise five subtypes with distinct tissue distributions and functions. Melanotan-2 is described in the literature as a non-selective agonist that engages several of these subtypes, including MC1R, MC3R, MC4R, and MC5R. MC1R is the subtype most directly linked to melanin production in skin cells. Because the compound is not subtype-selective, its observed effects in experimental settings are generally attributed to activity across multiple receptor pathways rather than to a single target.
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.
Lyophilized peptide powder is generally stored frozen, protected from light and moisture. Tryptophan residues are susceptible to oxidation, and the lactam bridge can hydrolyze under strongly acidic or basic conditions. Solutions prepared for laboratory work degrade faster than dry powder, and repeated freeze-thaw cycles accelerate loss. Common practice is to aliquot solutions before freezing and to avoid alkaline buffers. Reported stability windows vary with concentration, buffer, and temperature, so exact shelf lives are method-specific rather than universal.
Regulatory status differs by country, and in many places supplying the compound for human consumption is unlawful. Vendors frequently label material as intended for research use only, a designation that shifts stated purpose but does not create a legal pathway for personal use. Certificates of analysis accompanying such products vary widely in detail and provenance. Third-party testing exists but is voluntary, and results are rarely linked to a specific lot in a publicly verifiable way.
Identity testing for a synthetic peptide relies on several complementary methods. Reversed-phase high-performance liquid chromatography separates the target from related impurities and reports purity as a percentage of total peak area. Mass spectrometry confirms molecular mass and can reveal deletions or truncations. Amino acid analysis and peptide mapping provide sequence-level confirmation, while counter-ion content and residual solvents are measured separately. A purity figure alone does not establish identity, so a complete dataset combines chromatographic and spectrometric evidence.
Until the time of Napoleon, European states employed relatively small armies, made up of both national soldiers and mercenaries. These regulars were highly drilled, professional soldiers. Ancien Régime armies could only deploy small field armies due to rudimentary staffs and comprehensive yet cumbersome logistics. Military innovators in the mid-18th century began to recognise the potential of an entire nation at war: a "nation in arms". The scale of warfare dramatically enlarged during the Revolutionary and subsequent Napoleonic Wars. During Europe's major pre-revolutionary war, the Seven Years' War of 1756–1763, few armies ever numbered more than 200,000 with field forces often numbering less than 30,000. The French innovations of separate corps (allowing a single commander to efficiently command more than the traditional command span of 30,000 men) and living off the land (which allowed field armies to deploy more men without requiring an equal increase in supply arrangements such as depots and supply trains) allowed the French republic to field much larger armies than their opponents. Napoleon ensured during the time of the French republic that separate French field armies operated as a single army under his control, often allowing him to substantially outnumber his opponents. This forced his continental opponents to also increase the size of their armies, moving away from the traditional small, well-drilled Ancien Régime armies of the 18th century to mass conscript armies.
=== Folk remedies === Leaves of Heliotropium foertherianum (Boraginaceae) – also known as octopus bush – are used in many Pacific islands as a traditional medicine to treat ciguatera fish poisoning. Octopus bush leaves contain rosmarinic acid and derivatives, which are known for their antiviral, antibacterial, antioxidant, and anti-inflammatory properties. An account of ciguatera poisoning from a linguistics researcher living on Malakula island, Vanuatu, indicates the local treatment: "We had to go with what local people told us: avoid salt and any seafood. Eat sugary foods. And they gave us a tea made from the roots of ferns growing on tree trunks. I don't know if any of that helped, but after a few weeks, the symptoms faded away". Various Caribbean folk and ritualistic treatments originated in Cuba and nearby islands. The most common old-time remedy involves bed rest subsequent to a guanabana juice enema. In Puerto Rico, natives drink a tea made from mangrove buttons, purportedly high in B vitamins, to flush the toxic symptoms from the system. There has never been a funded study of these treatments. Other folk treatments range from directly porting and bleeding the gastrointestinal tract to "cleansing" the diseased with a dove during a Santería ritual.
pseudomallei in 99% of cases, as does the automated Vitek 1 system, but the automated Vitek 2 system only identifies 19% of isolates. The pattern of resistance to antimicrobials is distinctive, and helps to differentiate the organism from P. aeruginosa. The majority of B. pseudomallei isolates are intrinsically resistant to all aminoglycosides (via an efflux pump mechanism), but sensitive to co-amoxiclav: this pattern of resistance almost never occurs in P. aeruginosa and is helpful in identification. Unfortunately, the majority of strains in Sarawak, Borneo, are susceptible to aminoglycosides and macrolides, which means the conventional recommendations for isolation and identification do not apply there. Molecular methods (PCR) of diagnosis are possible, but not routinely available for clinical diagnosis. Fluorescence in situ hybridisation has also been described, but has not been clinically validated, and it is not commercially available. In Thailand, a latex agglutination assay is widely used, while a rapid immunofluorescence technique is also available in a small number of centres.
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.
== Mechanism of action == Brimonidine is an α2 adrenergic agonist. Peripheral α2 agonist activity results in vasoconstriction of blood vessels (as opposed to central α2 agonist activity that decreases sympathetic tone, as can be seen by the medication clonidine). This vasoconstriction may explain the acute reduction in aqueous humor flow. The increased uveoscleral outflow from prolonged use may be explained by increased prostaglandin release due to α adrenergic stimulation. This may lead to relaxed ciliary muscle and increased uveoscleral outflow.
Sources: en.wikipedia.org
== Aging studies == A gradual increase in CD38 has been implicated in the decline of NAD+ with age. Treatment of old mice with a specific CD38 inhibitor, 78c, prevents age-related NAD+ decline. CD38 knockout mice have twice the levels of NAD+ and are resistant to age-associated NAD+ decline, with dramatically increased NAD+ levels in major organs (liver, muscle, brain, and heart). On the other hand, mice overexpressing CD38 exhibit reduced NAD+ and mitochondrial dysfunction. Macrophages are believed to be primarily responsible for the age-related increase in CD38 expression and NAD+ decline. Cellular senescence of macrophages increases CD38 expression. Macrophages accumulate in visceral fat and other tissues with age, leading to chronic inflammation. The inflammatory transcription factor NF-κB and CD38 are mutually activating. Secretions from senescent cells induce high levels of expression of CD38 on macrophages, which becomes the major cause of NAD+ depletion with age. Decline of NAD+ in the brain with age may be due to increased CD38 on astrocytes and microglia, leading to neuroinflammation and neurodegeneration.
== Responsibilities == The Treuhand was responsible for more than just the 8,500 state-owned enterprises. It also took over around 2.4 million hectares of agricultural land and forests, the property of the former Stasi, large parts of the property of the former National People's Army, large-scale public housing property, and the property of the state pharmacy network. On 3 October 1990, the day of reunification, it took over the property of the SED, as well as the other political parties and the mass organisations of the National Front.
In August 2006, the court accepted the settlement between RTM and Access Now. The result was that every year, 100 of the RTM stores would be retrofitted to comply with the ADA. Accordingly, it was estimated that about $1.2 million would be spent to retrofit those stores each year. In 2008, Triarc purchased Wendy's, and changed its name to Wendy's/Arby's Group, to reflect their core businesses. In January 2011, it was announced that Wendy's/Arby's Group was looking into selling the Arby's side of the business to focus on the Wendy's brand. It was officially announced the companies would split on January 21, 2011. In 2009, the Wendy's/Arby's Group signed a franchise deal with the Al Jammaz Group of Saudi Arabia to open dual-branded Wendy's/Arby's through the Middle East with the first location opening in Dubai in the United Arab Emirates in May 2010. The Wendy's/Arby's Group also signed a similar franchise deal in June 2010 with Tab Gida Sanayi ve Ticaret to open dual-branded restaurants in Turkey. After the split, the former Wendy's/Arby's Group became The Wendy's Company.
1903 – Simon Lake submarine Protector surfaced through ice off Newport, Rhode Island. 1930 – USS O-12 operated under ice near Spitsbergen. 1937 – Soviet submarine Krasnogvardeyets operated under ice in the Denmark Strait. 1941–45 – German U-boats operated under ice from the Barents Sea to the Laptev Sea. 1946 – USS Atule used upward-beamed fathometer in Operation Nanook in the Davis Strait. 1946–47 – USS Sennet used under-ice sonar in Operation High Jump in the Antarctic. 1947 – USS Boarfish used upward-beamed echo sounder under pack ice in the Chukchi Sea. 1948 – USS Carp developed techniques for making vertical ascents and descents through polynyas in the Chukchi Sea. 1952 – USS Redfish used an expanded upward-beamed sounder array in the Beaufort Sea. 1957 – USS Nautilus reached 87 degrees north near Spitsbergen. 3 August 1958 – Nautilus used an inertial navigation system to reach the North Pole. 17 March 1959 – USS Skate surfaced through the ice at the north pole. 1960 – USS Sargo transited 900 miles (1,400 km) under ice over the shallow (125 to 180 feet or 38 to 55 metres deep) Bering-Chukchi shelf. 1960 – USS Seadragon transited the Northwest Passage under ice. 1962 – Soviet November-class submarine K-3 Leninsky Komsomol reached the north pole. 1970 – USS Queenfish carried out an extensive undersea mapping survey of the Siberian continental shelf. 1971 – HMS Dreadnought reached the North Pole. USS Gurnard conducted three Polar Exercises: 1976 (with US actor Charlton Heston aboard); 1984 joint operations with USS Pintado; and 1990 joint exercises with USS Seahorse.
Sources: en.wikipedia.org
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.
Afamelanotide is the linear analogue [Nle4-D-Phe7]-alpha-MSH, sometimes called melanotan I, while melanotan II is cyclic and carries three further substitutions. The two are distinct molecules and are not interchangeable in analytical testing.
Binding to the four melanocortin receptor subtypes is well documented in vitro. The relative contribution of each subtype to whole-body effects in humans is far less certain.
The dry powder is more stable during transport and storage than a solution. It also allows a known amount of material to be reconstituted at a chosen concentration.