If you have been reading about alpha-MSH analogue and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-05-10. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Lyophilised storage | −20 °C, dry, protected from light | Vials are sealed and allowed to reach room temperature before opening |
| Reconstituted storage | 2 to 8 °C, protected from light | Short-term holding; avoid repeated freeze-thaw cycles |
| Reconstitution solvent | Water for injection or bacteriostatic water | Added slowly along the vial wall to reduce foaming and shear |
| Purity measurement | RP-HPLC with area normalisation | Acetonitrile-water gradient monitored at roughly 214 nm |
| Identity confirmation | Electrospray ionisation mass spectrometry | Observed mass compared against the calculated peptide mass |
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.
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.
The peptide was developed during the 1980s by researchers investigating melanocortin signalling and skin pigmentation pathways. Early work focused on analogues of alpha-melanocyte-stimulating hormone that would resist enzymatic breakdown more effectively than the parent molecule. Melanotan-2 emerged from that programme as a shortened, cyclised variant. Reports describing its synthesis and receptor activity later appeared in the scientific literature. Commercial availability grew through unregulated channels rather than through pharmaceutical approval.
Structurally, Melanotan-2 retains the core recognition motif of alpha-melanocyte-stimulating hormone while adding a lactam bridge that links two side chains and constrains the molecule into a ring. This modification lowers susceptibility to enzymatic degradation. The compound acts as an agonist at melanocortin receptors, particularly subtypes associated with melanin production. Because the same receptor family influences several physiological processes, researchers note that its activity is not confined to pigmentation alone. Receptor selectivity continues to be examined in published studies.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its sequence incorporates modified residues that increase potency and extend biological activity relative to the native hormone. The compound binds receptors of the melanocortin family and is examined mainly in laboratory research. It does not occur naturally and exists only as a manufactured chemical entity produced by solid-phase synthesis.
Solid peptide material is generally stable when kept cold and dry. Common practice is storage at -20 degrees Celsius or lower, with desiccant and protection from light. Repeated freeze-thaw cycles and exposure to moisture are associated with degradation, aggregation, or loss of material. Once dissolved, stability depends on solvent, concentration, and temperature, and solutions are usually treated as short-lived unless stability data support longer periods. Handling notes typically emphasise minimising time at ambient temperature.
Identity and purity are assessed with chromatographic and mass spectrometric techniques. Reversed-phase high-performance liquid chromatography separates the target peptide from related impurities and degradation products, and the resulting retention time is compared against a reference standard. Mass spectrometry, often coupled to liquid chromatography, confirms molecular mass. Amino acid analysis or peptide mapping can provide additional sequence-level confirmation when required. Results are only as reliable as the reference materials used alongside them.
==== Traumatic calcinosis cutis ==== Traumatic calcinosis cutis is a cutaneous condition characterized by calcification of the skin resulting from the deposition of calcium and phosphorus often resulting from occupational exposure, as in cases reported in oil-field workers and coal miners.
However, the failure of D2 dopamine receptor antagonism, or dopamine receptor dysfunction, do not fully explain the presenting symptoms and signs of NMS, as well as the occurrence of NMS with atypical antipsychotic drugs with lower D2 dopamine activity. This has led to the hypothesis of sympathoadrenal hyperactivity (results from removing tonic inhibition from the sympathetic nervous system) as a mechanism for NMS. Release of calcium is increased from the sarcoplasmic reticulum with antipsychotic usage. This can result in increased muscle contractility, which can play a role in the breakdown of muscle, muscle rigidity, and hyperthermia. Some antipsychotic drugs, such as typical antipsychotics, are known to block dopamine receptors; other studies have shown that when drugs supplying dopamine are withdrawn, symptoms similar to NMS present themselves. In support of the sympathoadrenal hyperactivity model, it has been hypothesized that a defect in calcium regulatory proteins within the sympathetic neurons may bring about the onset of NMS. This model of NMS strengthens its suspected association with malignant hyperthermia in which NMS may be regarded as a neurogenic form of this condition which itself is linked to defective calcium-related proteins. There is also thought to be considerable overlap between malignant catatonia and NMS in their pathophysiology, the former being idiopathic and the latter being the drug-induced form of the same syndrome.
The pastel shades of turquoise have endeared it to many great cultures of antiquity: it has adorned the rulers of Ancient Egypt, the Aztecs (and possibly other Pre-Columbian Mesoamericans), Persia, Mesopotamia, the Indus Valley, and to some extent in ancient China since at least the Shang dynasty. Despite being one of the oldest gems, probably first introduced to Europe (through Turkey) with other Silk Road novelties, turquoise did not become important as an ornamental stone in the West until the 14th century, following a decline in the Roman Catholic Church's influence which allowed the use of turquoise in secular jewellery. It was apparently unknown in India until the Mughal Empire period, and unknown in Japan until the 18th century. A common belief shared by many of these civilizations held that turquoise possessed certain prophylactic qualities; it was thought to change colour with the wearer's health and protect him or her from untoward forces. The Aztecs viewed turquoise as an embodiment of fire and gave it properties such as heat and smokiness. They inlaid turquoise, together with gold, quartz, malachite, jet, jade, coral, and shells, into provocative (and presumably ceremonial) mosaic objects such as masks (some with a human skull as their base), knives, and shields. Natural resins, bitumen and wax were used to bond the turquoise to the objects' base material; this was usually wood, but bone and shell were also used.
According to these rules, compounds with the most ionic character will have large positive ions with a low charge, bonded to a small negative ion with a high charge. More generally HSAB theory can be applied, whereby the compounds with the most ionic character are those consisting of hard acids and hard bases: small, highly charged ions with a high difference in electronegativities between the anion and cation. This difference in electronegativities means that the charge separation, and resulting dipole moment, is maintained even when the ions are in contact (the excess electrons on the anions are not transferred or polarized to neutralize the cations). Although chemists classify idealized bond types as being ionic or covalent, the existence of additional types such as hydrogen bonds and metallic bonds, for example, has led some philosophers of science to suggest that alternative approaches to understanding bonding are required. This could be by applying quantum mechanics to calculate binding energies.
=== Sports === As Rhodesia was a former colony of the United Kingdom, all of the sports that were born in the United Kingdom enjoyed considerable popularity in Rhodesia; especially cricket, rugby, water polo, football, netball, golf, tennis (including the Rhodesian Open Tennis Championships), lawn bowls, field hockey, etc. Just like neighbouring South Africa, Rhodesia was barred from both competing against and participating with Commonwealth member countries. One of the biggest triumphs in Rhodesia sports history was when the team defeated the New Zealand national rugby team 10-8 while the All Blacks were touring South Africa. They are 1 of 8 nations to ever defeat the All Blacks and the only non-test nation to have ever beaten them.
Sources: en.wikipedia.org
While iron is the most abundant element on Earth, most of this iron is concentrated in the inner and outer cores. The fraction of iron that is in Earth's crust only amounts to about 5% of the overall mass of the crust and is thus only the fourth most abundant element in that layer (after oxygen, silicon, and aluminium). Most of the iron in the crust is combined with various other elements to form many iron minerals. An important class is the iron oxide minerals such as hematite (Fe2O3), magnetite (Fe3O4), and siderite (FeCO3), which are the major ores of iron. Many igneous rocks also contain the sulfide minerals pyrrhotite and pentlandite. During weathering, iron tends to leach from sulfide deposits as the sulfate and from silicate deposits as the bicarbonate. Both of these are oxidized in aqueous solution and precipitate in even mildly elevated pH as iron(III) oxide.
== Definition == Urea and creatinine are nitrogenous end products of metabolism. Urea is the primary metabolite derived from dietary protein and tissue protein turnover. Creatinine is the product of muscle creatine catabolism. Both are relatively small molecules (60 and 113 daltons, respectively) that distribute throughout total body water. In Europe, the whole urea molecule is assayed, whereas in the United States only the nitrogen component of urea (the blood or serum urea nitrogen, i.e., BUN or SUN) is measured. The BUN, then, is roughly one-half (7/15 or 0.466) of the blood urea. The normal range of urea nitrogen in blood or serum is 5 to 20 mg/dl, or 1.8 to 7.1 mmol urea per liter. The range is wide because of normal variations due to protein intake, endogenous protein catabolism, state of hydration, hepatic urea synthesis, and renal urea excretion. A BUN of 15 mg/dl would represent significantly impaired function for a woman in the thirtieth week of gestation. Her higher glomerular filtration rate (GFR), expanded extracellular fluid volume, and anabolism in the developing fetus contribute to her relatively low BUN of 5 to 7 mg/dl. In contrast, the rugged rancher who eats in excess of 125 g protein each day may have a normal BUN of 20 mg/dl. The normal serum creatinine (sCr) varies with the subject's body muscle mass and with the technique used to measure it. For the adult male, the normal range is 0.6 to 1.2 mg/dl, or 53 to 106 μmol/L by the kinetic or enzymatic method, and 0.8 to 1.5 mg/dl, or 70 to 133 μmol/L by the older manual Jaffé reaction.
It is very important to quickly cool the wort to a level where yeast can be added safely as yeast is unable to grow in very high temperatures, and will start to die in temperatures above 60 °C (140 °F). After the wort goes through the heat exchanger, the cooled wort goes into a fermentation tank. A type of yeast is selected and added, or "pitched", to the fermentation tank. When the yeast is added to the wort, the fermenting process begins, where the sugars turn into alcohol, carbon dioxide and other components. When the fermentation is complete the brewer may rack the beer into a new tank, called a conditioning tank. Conditioning of the beer is the process in which the beer ages, the flavour becomes smoother, and flavours that are unwanted dissipate. After conditioning for a week to several months, the beer may be filtered and force carbonated for bottling, or fined in the cask.
The Cold War emerged from the breakdown of relations between two of the primary victors of World War II: the United States and Soviet Union, along with their respective allies in the Western Bloc and Eastern Bloc. This ideological and political rivalry, which solidified between 1945–1949, would shape the global order for the next four decades. The roots of the Cold War can be traced back to diplomatic and military tensions preceding World War II. The 1917 Russian Revolution and the subsequent Treaty of Brest-Litovsk, where Soviet Russia ceded vast territories to Germany, deepened distrust among the Western Allies. Allied intervention in the Russian Civil War further complicated relations, and although the Soviet Union later allied with Western powers to defeat Nazi Germany, this cooperation was strained by mutual suspicions. In the immediate aftermath of World War II, disagreements about the future of Europe, particularly Eastern Europe, became central. The Soviet Union's establishment of communist regimes in the countries it had liberated from Nazi control—enforced by the presence of the Red Army—alarmed the United States and United Kingdom. Western leaders saw this as a clear instance of Soviet expansionism, clashing with their vision of a democratic Europe. Economically, the divide was sharpened with the introduction of the Marshall Plan in 1947, a US initiative to provide financial aid to rebuild Europe and prevent the spread of communism by stabilizing capitalist economies.
Asthma, traditionally considered an absolute contraindication. This is being contested, and it is now considered a relative contraindication (however, selective adenosine antagonists are being investigated for use in treatment of asthma)
Sources: en.wikipedia.org
Analysts have long believed that the firm's corporate governance must determine how to contend with higher materials prices and enhanced competition from lower-priced fast-food chains, including McDonald's and Dunkin' Donuts. In October 2015, Starbucks hired its first chief technology officer, Gerri Martin-Flickinger, to lead its technology team. Starbucks maintains control of production processes by communicating with farmers to secure beans, roasting its own beans, and managing distribution to all retail locations. Additionally, Starbucks's Coffee and Farmer Equity Practices require suppliers to inform Starbucks what portion of wholesale prices paid reaches farmers. Shortly after becoming CEO, Niccol announced a new 'Back to Starbucks' strategy to win back customers. The plan including simplifying the menu and reversing rules for its cafes in North America that had allowed people to use their facilities even if they had not bought anything. On December 19, 2025, Starbucks announced Amazon's Anand Varadarajan as new chief technology officer, effective January 19, 2026.
Competition with endogenous aldehydes or ketones in metabolites and cofactors, resulting in low yields and impaired specificity. Side reactions, such as oxidation or unwanted addition of endogenous nucleophiles. Restrained set of probes that form sufficiently stable products. Aldehydes and ketones are therefore best used in compartments where such unwanted side reactions are decreased. For experiments with live cells, cell surfaces and extracellular space are typical fielding areas. Nevertheless, a feature of carbonyl groups is the vast number of organic reactions that involve them as electrophiles. Some of these reactions are readily convertible to ligations for probing aldehydes. A reaction recently employed for bioconjugation by Agarwal et al. is the adaptation of the Pictet-Spengler reaction as a ligation. The reaction is known from natural product biosynthetic pathways and has the major advantage of forming a new carbon-carbon bond. This guarantees long-term stability compared to carbon-heteroatom bonds with similar reaction kinetics. The modification of cysteine or, more rarely, serine by FGE is an uncommon posttranslational modification that was discovered in the late 1990s. The deficiency of FGE leads to an overall deficiency of functional sulfatases due to a lack of α-formylglycine formation vital for the sulfatases to perform their function. FGE is essential for protein modification and need of high specificity and conversion rate is given in the native setting, which makes this reaction applicable in chemical and synthetic biology.
=== Animal welfare citations by the United States Department of Agriculture === In June 2011, a report showed that improper housing conditions led to frostbite on the tails of many monkeys. In February 2012, the company was cited after a monkey died after being entangled by an enrichment device. In March 2012, the company was cited for housing a monkey in isolation for almost eight months.
In 1991, the Proceeds of Crime (Money Laundering) Act was brought into force in Canada to give legal effect to the former FATF Forty Recommendations by establishing record keeping and client identification requirements in the financial sector to facilitate the investigation and prosecution of money laundering offences under the Criminal Code and the Controlled Drugs and Substances Act. In 2000, the Proceeds of Crime (Money Laundering) Act was amended to expand the scope of its application and to establish a financial intelligence unit with national control over money laundering, namely FINTRAC. In December 2001, the scope of the Proceeds of Crime (Money Laundering) Act was again expanded by amendments enacted under the Anti-Terrorism Act with the objective of deterring terrorist activity by cutting off sources and channels of funding used by terrorists in response to 9/11. The Proceeds of Crime (Money Laundering) Act was renamed the Proceeds of Crime (Money Laundering) and Terrorist Financing Act. In December 2006, the Proceeds of Crime (Money Laundering) and Terrorist Financing Act was further amended, in part, in response to pressure from the FATF for Canada to tighten its money laundering and financing of terrorism legislation.
Sources: en.wikipedia.org
Low temperature slows hydrolysis and oxidation, the two main routes by which the peptide backbone and side chains are modified. A lyophilised powder stored at −20 °C is more stable than one kept at room temperature, and once the material is dissolved the degradation rate rises, making refrigeration more important.
Liquid chromatography coupled to mass spectrometry is the most common approach because it combines a retention time with a mass measurement. A chromatographic peak alone cannot establish which peptide is present, so mass determination or amino acid analysis is used as an orthogonal confirmation alongside the separation.
This depends on buffer, pH, and concentration, and published stability data for this peptide are limited. In practice laboratories work through a refrigerated solution within a few weeks and discard samples that show cloudiness or visible particles. Freezing and thawing repeatedly is generally discouraged.
It is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, containing seven amino acids with a lactam ring and a D-configured phenylalanine residue. It is supplied as a lyophilised powder for laboratory research.