If you have been reading about alpha-MSH 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 2026-02-18. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
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.
| 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 |
Receptor studies place melanotan-2 among non-selective melanocortin agonists, binding MC1R, MC3R, MC4R and MC5R rather than a single subtype. Activation of MC1R on cutaneous melanocytes raises tyrosinase activity and shifts pigment synthesis toward eumelanin, which is darker and more photostable than pheomelanin. Central receptors, particularly MC4R, are associated with appetite suppression and with reported effects on sexual function. Because subtype selectivity is low, the same molecule engages pigment, metabolic and vascular pathways at once, and this breadth is a common explanation offered for the range of adverse events described in user reports.
No regulatory authority has approved melanotan-2 for human use, and several countries classify it as a prescription-only or controlled substance, which restricts lawful supply. Material sold online is generally labelled as a research chemical and is not required to meet pharmaceutical standards of identity or purity. Published human data consist mainly of small uncontrolled studies, case reports and adverse-event notifications, so the evidence base is descriptive rather than confirmatory. Whether repeated melanocyte stimulation alters long-term naevus behaviour remains an open question that no completed trial has resolved.
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.
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.
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.
== Mechanical characteristics == At small strains, elastin confers stiffness to the tissue and stores most of the strain energy. The collagen fibers are comparatively inextensible and are usually loose (wavy, crimped). With increasing tissue deformation the collagen is gradually stretched in the direction of deformation. When taut, these fibers produce a strong growth in tissue stiffness. The composite behavior is analogous to a nylon stocking, whose rubber band does the role of elastin as the nylon does the role of collagen. In soft tissues, the collagen limits the deformation and protects the tissues from injury. Human soft tissue is highly deformable, and its mechanical properties vary significantly from one person to another. Impact testing results showed that the stiffness and the damping resistance of a test subject's tissue are correlated with the mass, velocity, and size of the striking object. Such properties may be useful for forensics investigation when contusions were induced. When a solid object impacts a human soft tissue, the energy of the impact will be absorbed by the tissues to reduce the effect of the impact or the pain level; subjects with more soft tissue thickness tended to absorb the impacts with less aversion.
== Paleontology == The oldest known fossil of Conidae is from the lower Eocene, about 55 million years ago. Analysis of nucleotide sequences indicate that all living species of Conidae belong to one of two clades that diverged about 33 million years ago. One clade includes most of the species in the eastern Pacific and western Atlantic regions, which were connected by the Central American Seaway until the emergence of the Isthmus of Panama less than three million years ago. The other clade includes most of the species in the eastern Atlantic and Indo-Pacific regions, which were connected by the Neo-Tethys Sea until 21 to 24 million years ago.
=== Crohn's disease === Three phenotypes, or categories of disease, are present in Crohn's disease: stricturing disease (which causes narrowing of the bowel), penetrating disease (which causes fistulae or abnormal connections of the bowel), and inflammatory disease (which primarily causes inflammation).
In the first case of a woman being sentenced to death in Singapore, dance hostess Mimi Wong Weng Siu was convicted of murdering Ayako Watanabe out of jealousy in 1970 and received the death sentence in the same trial as her ex-husband Sim Woh Kum, who assisted her in killing the Japanese victim, who was the wife of Wong's Japanese boyfriend. The couple were executed on 27 July 1973.
=== Measurement === Platelet concentration in the blood (i.e. platelet count), can be measured manually using a hemocytometer, or by placing blood in an automated platelet analyzer using particle counting, such as a Coulter counter or optical methods. Most common blood testing methods include platelet count in their measurements, usually reported as PLT. Platelet concentrations vary between individuals and over time, with the population average between 250,000 and 260,000 cells per mm3 (equivalent to per microliter), but the typical laboratory accepted normal range is between 150,000 and 400,000 cells per mm3 or 150–400 billion per liter.
Sources: en.wikipedia.org
Due to backstreaming, oil diffusion pumps are not suitable for use with highly sensitive analytical equipment or other applications which require an extremely clean vacuum environment, but mercury diffusion pumps may be in the case of ultra high vacuum chambers used for metal deposition. Often cold traps and baffles are used to minimize backstreaming, although this results in some loss of pumping speed. The oil of a diffusion pump cannot be exposed to the atmosphere when hot. If this occurs, the oil will oxidise and has to be replaced. If a fire occurs, the smoke and residue may contaminate other parts of the system.
Neanderthal pigmentation genes in modern non-African people are associated with both lighter and darker skin tones, as well as lighter and darker hair colors, suggesting Neanderthals themselves may have had variable pigmentation. Variants associated with red hair have been found in some Neanderthals, but they do not appear to have been common. Neanderthal skin and hair pigmentation variants are under positive selection in non-Africans, unlike most other Neanderthal genes, suggesting that the adaptive value of lighter features was beneficial for modern humans in Eurasia, where there is significantly less sunlight as compared to Africa.
A top-secret White paper, compiled by the Royal Air Force and produced for the British Government in 1959, estimated that British V bombers carrying nuclear weapons were capable of destroying key cities and military targets in the Soviet Union, with an estimated 16 million deaths in the Soviet Union (half of whom were estimated to be killed on impact and the rest fatally injured) before bomber aircraft from the U.S. Strategic Air Command reached their targets.
=== Cancer immunotherapy === Garcia has conducted several studies targeting cellular receptors for applications in cancer immunotherapy. In 2013, Garcia's group developed high affinity antagonists of the receptor CD47 that potently enhance the antitumor effects of established therapeutic antibodies. Garcia later determined that the therapeutic effects of CD47 blockade require combination therapy with checkpoint blockade antibodies in immunocompetent hosts, thus proving that CD47-based therapy relies upon stimulation of the adaptive immune system. Garcia's lab published the creation of an "orthogonal" IL-2 receptor complex to enable the selective delivery of IL-2 signals to engineered T cells during adoptive cell therapy. They also reported a new technology using yeast-displayed peptide-MHC molecules to identify tumor antigens recognized by Tumor Infiltrating Lymphocytes.
Sources: en.wikipedia.org
=== Gas treatment === Aqueous monoethanolamine (MEA), diglycolamine (DGA), diethanolamine (DEA), diisopropanolamine (DIPA) and methyldiethanolamine (MDEA) are widely used industrially for removing carbon dioxide (CO2) and hydrogen sulfide (H2S) from natural gas and refinery process streams. They may also be used to remove CO2 from combustion gases and flue gases and may have potential for abatement of greenhouse gases. Related processes are known as sweetening.
== Toxicity == The phototoxic effects of bergamot essential oil have been known at least since 1925 when Rosenthal coined the term "Berloque dermatitis" (from the French word "breloque" meaning trinket or charm) to describe the pendant-like streaks of pigmentation observed on the neck, face, and arms of patients. He was unaware that, in 1916, Freund had correctly observed that these pigmentation effects were due to sun exposure after the use of Eau de Cologne, a perfume infused with bergamot oil. Use of bergamot aromatherapy oil, followed by exposure to ultraviolet light (either sunlight or a tanning bed), has been reported to cause phytophotodermatitis, a serious skin inflammation indicated by painful erythema and bullae on exposed areas of the skin. In one case, six drops of bergamot aromatherapy oil in a bath followed by 20–30 minutes exposure of ultraviolet light from a tanning bed caused a severe burn-like reaction.
Specialized variants of field rations may exist for different environments, situations, and roles, such as cold-weather warfare, mountain warfare, jungle warfare, desert warfare, long-range reconnaissance patrols, and vehicle crew variants. The meals offered in a field ration often come in multiple different "menus" (varieties) predominantly featuring foods from a military's national or traditional cuisine—and, if diverse enough and possible under the constraints of a field ration, fusion cuisine such as soul food or Anglo-Indian cuisine—intended to evoke the "taste of home" while on deployment or away. Some rations include commercially available items, often snacks such as Tootsie Rolls, Charms, and Yorkie bars. However, basic or less-accommodating rations (usually emergency rations) may consist of very simple meals intended to provide enough nutrients and energy to keep a soldier combat-ready or alive, like compressed food bars. Field rations are commonly issued to land forces such as armies, marines, and air force ground forces, who may spend lengthy periods of time away from fixed food sources. Navies and air forces are not commonly issued field rations as they are closely attached to the rear or steady supplies of food, prepared in galleys aboard naval vessels and flight kitchens at air bases. Rations may still be issued to personnel in certain situations or roles, like long-range flight rations for bomber, transport, and reconnaissance aircraft crews, who could otherwise spend hours in flight without food.
An unexpected medical problem that happens during treatment with a drug or other therapy. Adverse events do not have to be caused by the drug or therapy, and they may be mild, moderate, or severe. (NCI) An AE is any untoward medical occurrence in a patient or clinical investigation subject administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An AE can therefore be any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product (see the ICH guidance for Clinical Safety Data Management: Definitions and Standards for Expedited Reporting). (ICH E6) Adverse reaction
=== Marriages and children === Galloway has been married four times and has six children. In 1979, he married Elaine Fyffe, with whom he has a daughter. The couple separated in 1987 and divorced in 1999. In 1994, Galloway married Amineh Abu-Zayyad, a Palestinian biologist, in a non-legally binding Islamic ceremony; a legally binding civil ceremony followed in March 2000. Abu-Zayyad was granted a divorce in February 2009, after an estrangement of several years, on the grounds of "unreasonable behaviour"; her petition was not contested. Galloway married Rima Husseini, his former researcher, in a non-legally binding Islamic ceremony in 2005. Galloway had two sons with Husseini, who is from Lebanon. On 31 March 2012 he married his fourth wife, the Dutch–Indonesian anthropologist Putri Gayatri Pertiwi, then 27, in Amsterdam. The initial event was followed by a traditional Javanese wedding ceremony in Sumatra and a civil marriage at the House of Commons in September 2012. Pertiwi worked as a consultant for a Dutch research firm and as a co-presenter of Galloway's TV show Sputnik. The couple have three children.
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.
It is a synthetic cyclic heptapeptide modelled on alpha-melanocyte-stimulating hormone. A lactam bridge links two side chains, forming a ring that stabilises the molecule against proteolysis. It belongs to the broader melanocortin peptide family.