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.
Updated 2026-03-10. Numbers and descriptions here follow the published literature rather than marketing material.
Handling guidance for melanotan II follows general practice for small synthetic peptides rather than a product-specific monograph. Lyophilized powder is typically kept at minus twenty degrees Celsius or colder, protected from light and moisture, because warmth and humidity accelerate degradation. Once reconstituted, solutions are usually refrigerated and used within a short window, as hydrolysis and microbial growth both become concerns. Repeated freeze-thaw cycles are generally avoided. These conventions come from laboratory peptide chemistry and not from formal stability studies on this specific compound.
Analytical confirmation of identity relies on mass spectrometry, most often coupled to liquid chromatography. Reversed-phase high-performance liquid chromatography separates the peptide from related impurities and provides a purity estimate based on peak area. Electrospray ionization mass spectrometry then confirms the expected molecular mass, while tandem mass spectrometry can map the fragment sequence. For research-grade material, these two techniques together form the standard minimum. Purity figures reported by vendors are frequently not traceable to an independent laboratory.
Independent verification is central to quality control because the compound is not produced under pharmaceutical manufacturing standards. Third-party laboratories can measure purity, identity, residual solvents, and microbial contamination, though the scope of testing varies between services. Reported analyses of vendor samples have shown batch-to-batch variation in peptide content and the presence of truncated or oxidized species. How much of this variation reflects synthesis conditions versus storage and shipping is not well characterized. No harmonized reference standard exists for the material as sold.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Freely soluble in water | Dissolves readily in aqueous buffer |
| Typical storage temperature | -20 °C or below | Protect from light and moisture |
| Typical analytical method | Reversed-phase HPLC and LC-MS | Purity estimate plus mass confirmation |
| Unit of measure | Milligram per vial | Content varies by vendor |
Identity testing for a cyclic peptide of this size usually relies on reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The mass spectrum confirms molecular weight, while the chromatographic trace indicates the proportion of related impurities. Tandem mass spectrometry can provide sequence-level information when fragmentation data are compared against a reference standard. Nuclear magnetic resonance is sometimes used to confirm the lactam bridge, although it requires more material and greater operator expertise than routine chromatographic methods.
Lyophilised peptide powder is comparatively stable when kept dry, cold and protected from light. Once dissolved, the molecule is exposed to hydrolysis, oxidation and microbial growth, and degradation accelerates at higher temperatures and in alkaline solution. Repeated freeze-thaw cycles concentrate solutes and promote aggregation. Handling guidance for research peptides commonly clusters around freezer temperatures for powder and short refrigerated use for reconstituted solutions, with pH control and sterile technique applied throughout.
Verification of a purchased sample requires documentation linking a batch to a certificate of analysis, and that document should be read for the methods used rather than the headline purity figure. A single chromatographic percentage does not establish identity. Independent laboratories can perform identity and content assays, but no such test establishes that a product is suitable for human use. Claims about efficacy rest largely on small, early studies rather than on replicated controlled trials, and that gap remains open.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence incorporates a lactam bridge that constrains the peptide into a ring, which increases resistance to enzymatic breakdown relative to the natural hormone. Researchers at the University of Arizona synthesised the compound in the late 1980s and early 1990s while studying pigmentation pathways. It has never received marketing approval from any national medicines regulator. In the scientific literature it is usually described as a laboratory research reagent rather than a therapeutic product.
The peptide acts as a non-selective agonist at melanocortin receptors, showing affinity for MC1R, MC3R, MC4R and MC5R. Activation of MC1R on melanocytes drives the conversion of tyrosine into melanin and shifts production toward the darker eumelanin form. MC4R signalling in the central nervous system is linked to appetite and energy balance, which helps explain why reduced food intake appeared in early human studies. Effects on MC4R and on vascular tone also account for the erectile responses recorded as unexpected findings in those same trials.
Melanotan-2 is frequently confused with afamelanotide, a linear analogue authorised in the European Union for erythropoietic protoporphyria. The two compounds differ in chain length, ring structure and receptor selectivity, so findings for one cannot be transferred directly to the other. Published controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports. Questions about effect size, dose-response behaviour and long-term safety therefore remain unresolved.
== Ecology == Dioecy, having separate male and female flowers, has evolved at least three times in the genus, and reversals to a hermaphrodite condition have also occurred, which is a rare occurrence in flowering plants. It has been suggested that dioecy in the genus may correlate with abiotic pollination in the cold environment.
These reformulations can be partly attributed to 2006 Center for Science in the Public Interest class action complaints, and to New York's restaurant trans fat ban, a massive effort led by Minal Amlani under the guidance of Michael Bloomberg, with companies such as McDonald's stating they would not be selling a unique product just for New York customers but would implement a nationwide or worldwide change.
=== 12 September === Ten people were killed in an RSF raid on the Al-Nasr neighborhood of El Fasher. The United States imposed sanctions on finance minister and Justice and Equality Movement leader Gibril Ibrahim and the Al-Bara' ibn Malik Battalion for their role in the civil war and connections with Iran.
== Research == According to a study released in 2015, a stop gain mutation in HBB gene (p. Gln40stop) was shown to be associated with ESR values in Sardinian population. The red blood cell count, whose values are inversely related to ESR, is affected in carriers of this SNP. This mutation is almost exclusive of the inhabitants of Sardinia and is a common cause of beta thalassemia. According to a 2010 study, there is a reverse correlation between ESR and general intelligence (IQ) in Swedish males aged 18–20.
Sources: en.wikipedia.org
== Contraindications == Nitrovasodilators are contraindicated under circumstances where lowering of blood pressure can be dangerous. This includes, with some variation between the individual substances, severe hypotension (low blood pressure), shock including cardiogenic shock, and anaemia. Whether a specific drug is useful or harmful under heart failure and myocardial infarction depends on its speed of action: Fast acting substances such as glyceryl trinitrate and nitroprusside can be helpful for controlling blood pressure and consequently the amount of blood the heart has to pump, if the application is monitored continuously. Slow acting substances would hold the danger of ischaemia due to an uncontrollably low blood pressure and are therefore contraindicated. Depending on the circumstances, even fast acting substances can be contraindicated – for example, glyceryl trinitrate in patients with obstructive heart failure. These drugs are also contraindicated in patients that have recently taken PDE5 inhibitors such as sildenafil (Viagra).
=== Colloquialisms === A large central adiposity deposit has been assigned many common use names, including "spare tire", "love handle", "paunch", "boiler", and "potbelly". Several colloquial terms used to refer to central obesity, and to people who have it, refer to beer drinking. However, there is little scientific evidence that beer drinkers are more prone to central obesity, despite its being known colloquially as "beer belly", "beer gut", or "beer pot". One of the few studies conducted on the subject did not find that beer drinkers are more prone to central obesity than nondrinkers or drinkers of wine or spirits. Chronic alcoholism can lead to cirrhosis, symptoms of which include gynecomastia (enlarged breasts) and ascites (abdominal fluid). These symptoms can suggest the appearance of central obesity.
IUPAC Nomenclature for Chromatography Overlapping Peaks Program – Learning by Simulations Chromatography Videos – MIT OCW – Digital Lab Techniques Manual Chromatography Equations Calculators – MicroSolv Technology Corporation
Sources: en.wikipedia.org
=== Fl–Fu === Louis B. Flexner (1902–1996). American biochemist at the University of Pennsylvania, who worked on the biochemistry of memory and brain function. Member Natl. Acad. Sci. USA. Otto Folin (1867–1934). Swedish-American chemist at Harvard, best known for developing methods for the determination of the constituents of protein-free blood filtrates. Member Natl. Acad. Sci. USA. Karl August Folkers (1906–1997). American biochemist at Merck, known for work on the antibiotics cathomycin and cycloserine. Ivar Asbjørn Følling (1888–1973). Norwegian biochemist and geneticist who first described phenylketonuria. Sidney W. Fox (1912–1998). American biochemist at the University of Miami who worked on the production of amino acids in abiotic conditions. Heinz Fraenkel-Conrat (1910–1999). German-American biochemist at UC Berkeley, known for research on viruses such as tobacco mosaic virus. Member Natl. Acad. Sci. USA. Rosalind Franklin (1920–1958). British X-ray crystallographer at King's and Birkbeck Colleges, London, who worked on the structure of DNA Perry A. Frey (b. 1935). American biochemist at the University of Wisconsin known for work on enzyme mechanisms. Member Natl. Acad. Sci. USA. Irwin Fridovich (1929–2019). American biochemist at Duke University, who discovered superoxide dismutase and studied its mechanisms and superoxide toxicity. Member Natl. Acad. Sci. USA. Joseph S. Fruton (1912–2007). Polish-American biochemist at the Rockefeller Institute.
=== Electromagnetic flux === In radio astronomy, the unit of electromagnetic flux is the jansky (symbol Jy), equivalent to 10−26 watts per square metre per hertz (= 10−26 kg/s2 in base units, about 8.8×10−31 BTU/ft2). It is named after the pioneering radio astronomer Karl Jansky. The brightest natural radio sources have flux densities of the order of one to one hundred jansky.
== External links == International HapMap Project Archived 2014-04-16 at the Wayback Machine Delaware Valley Personalized Medicine Project Uses SNPs to help make medicine personal Genotyping by Oligonucleotide Ligation Assay (OLA) Why SNP test your mice?
Sources: en.wikipedia.org
The lyophilized powder is generally held at minus twenty degrees Celsius or below, away from light and moisture. Reconstituted solutions are typically refrigerated and used quickly. These practices derive from general peptide handling rather than a formal stability study.
Reversed-phase liquid chromatography estimates purity, and mass spectrometry confirms molecular mass. Together they distinguish the intended peptide from truncated or modified forms. Sequence-level confirmation may use tandem mass spectrometry or amino acid analysis.
Because it is not made under pharmaceutical standards, purity and content can vary between vendors and batches. Independent testing has documented labeling discrepancies. A certificate of analysis from an accredited laboratory offers more assurance than a vendor's own claim.
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.