alpha-MSH analogue comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-03-16. Numbers and descriptions here follow the published literature rather than marketing material.
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controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports.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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Alpha-MSH analogue with a lactam ring |
| Molecular formula | C50H69N15O9 | Commonly cited value for the neutral peptide |
| Molecular weight | 1024.18 g/mol | Calculated for the free molecule |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water, DMSO and ethanol | Dissolution in pure water is often slow |
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.
The compound was developed in the late 1980s and early 1990s by academic researchers investigating melanocortin signaling and pigmentation. Early work explored whether synthetic analogs could reproduce effects of the natural hormone under controlled conditions. The molecule never advanced through the full regulatory pathway required for approval as a medicine. From the mid-2000s onward it appeared in unregulated consumer markets, often distributed through informal channels. That gap between research origins and commercial availability shapes how the compound is discussed today.
Melanotan-2 is a synthetic peptide designed as an analog of alpha-melanocyte-stimulating hormone, a signaling molecule produced in the pituitary and skin. Its structure is a linear chain of seven amino acids that folds into a ring through an internal lactam bridge joining two side chains. The compound is sometimes written as MT-II or MEL-2 in informal and commercial contexts. It belongs to the melanocortin peptide family, a group of short signaling molecules that share a conserved core sequence recognized by melanocortin receptors.
Melanotan II binds several melanocortin receptor subtypes rather than a single target. MC1R on melanocytes drives melanin synthesis, while MC3R and MC4R participate in energy balance, appetite, and sexual response pathways. This lack of selectivity explains why reported effects extend beyond skin darkening. Substitutions at positions four and seven, including norleucine and D-phenylalanine, increase potency and resistance to peptidases. Understanding which receptor mediates which effect remains an active area of investigation.
Published human data come mostly from small, short studies rather than large controlled trials. Reported outcomes include increased skin pigmentation and, in some reports, effects on appetite and libido, but sample sizes are small and follow-up is limited. Whether long-term use produces durable pigment changes or adverse effects is not established. Because products sold outside pharmacies are not standardized, the actual content of any given vial is often unknown. Independent testing of such material is uncommon.
Melanotan II is a synthetic cyclic heptapeptide analog derived from the core sequence of alpha-melanocyte-stimulating hormone. Researchers at the University of Arizona synthesized it during the 1980s while studying pigmentation and appetite signaling. The compound is not an approved medicine in any major jurisdiction and appears mainly in laboratory and research-chemical settings. Its structure incorporates a lactam bridge between side chains, which constrains the ring and slows enzymatic breakdown relative to the natural hormone.
==== I ==== Freeze-dried ice cream – is ice cream that has had most of the water removed from it by a freeze-drying process; sealed in a pouch, it requires no refrigeration. It achieved fame as a food in human spaceflight.
==== Bhutan ==== Meanwhile, in Bhutan, accessible by road only through India, there are interior border checkpoints (primarily on the Lateral Road) and, additionally, certain areas require special permits to enter, whilst visitors not proceeding beyond the border city of Phuentsholing do not need permits to enter for the day (although such visitors are de facto subject to Indian visa policy since they must proceed through Jaigaon). Individuals who are not citizens of India, Bangladesh, or the Maldives must obtain both their visa and any regional permits required through a licensed tour operator before arriving in the country. Citizens of India, Bangladesh, and the Maldives may apply online for regional permits to restricted areas.
Using the tool they designed virus-shaped scaffolding that can modularly attach different antigens to the surface of the DNA scaffold. Currently, MIT is working to develop optimal geometries for B cells to recognize HIV antigens. Further research has attempted to replace HIV antigens with SARS-CoV-2 and are testing whether vaccines show proper immune response from isolated B cells and in mice.
== Multi domain proteins == The adhesome contains multi domain proteins with various functions, some of which are specifically enriched in the adhesome compared to the cell proteome. Protein domains enriched in the adhesome include: Pleckstrin homology (PH) and FERM domains, which target proteins to the plasma membrane; Calponin homology (CH) domain, which is an F-actin binding motif; Src homology 2 (SH2) domain, which mediate interaction with phosphorylated tyrosine residues; armadillo (ARM) GUK and LIM domains, which mediate specific protein-protein binding. The literature-based adhesome contains enzymes, such as protein tyrosine and serine/threonine kinases and phosphatases, guanine nucleotide exchange factors and GTPase activating proteins, E3-ligases and proteases, that regulate adhesion through post translational modification of the many structural and scaffolding proteins found in the adhesome. The proteomic-based studies have identified many proteins from functional groups that haven't previously been associated with cell adhesion sites, such as proteins involved in RNA splicing, translation, trafficking, golgi, endoplasmic reticulum, and metabolic enzymes. Whether these proteins are indeed an integral part of the adhesome or an artifact of the proteomic methods remains to be seen.
Sources: en.wikipedia.org
The first generation uses linking technologies that conjugate drugs non-selectively to cysteine or lysine residues in the antibody, resulting in a heterogeneous mixture. This approach leads to suboptimal safety and efficacy and complicates optimization of the biological, physical and pharmacological properties. Site-specific incorporation of unnatural amino acids generates a site for controlled and stable attachment. This enables the production of homogeneous ADCs with the antibody precisely linked to the drug and controlled ratios of antibody to drug, allowing the selection of a best-in-class ADC. An Escherichia coli-based open cell-free synthesis (OCFS) allows the synthesis of proteins containing site-specifically incorporated non-natural amino acids and has been optimized for predictable high-yield protein synthesis and folding. The absence of a cell wall allows the addition of non-natural factors to the system to manipulate transcription, translation and folding to provide precise protein expression modulation.
Radiocarbon Dating and Chronological Modelling: Guidelines and Best Practice, Historic England OxCal, radiocarbon calibration program IntCal working group IntChron, indexing service for radiocarbon dates p3k14c, global radiocarbon database XRONOS, global radiocarbon database
The development of insulin therapy has progressed significantly since the early 20th century, starting with animal-derived insulins. In 1922, Frederick Banting and Charles Best successfully used bovine insulin extract to treat humans for the first time. This breakthrough led to the commercial production of bovine insulin in 1923 by Eli Lilly and Company. That same year, Hans Christian Hagedorn founded the Nordisk Insulinlaboratorium in Denmark, which later became Novo Nordisk. In 1926, Nordisk received a Danish charter to produce insulin as a non-profit entity. In 1936, Canadian researchers D.M. Scott and A.M. Fisher developed a zinc insulin mixture, which was licensed to Novo. During this time, Hagedorn discovered that adding protamine to insulin could prolong its action, which led to the development of Neutral Protamine Hagedorn (NPH) insulin in 1946. NPH insulin was marketed by Nordisk in 1950. By 1953, Novo also developed Lente insulin by adding zinc to porcine and bovine insulins, resulting in a longer-acting form. A significant advancement in insulin production occurred in 1978 when Genentech developed the biosynthesis of recombinant human insulin using Escherichia coli bacteria and recombinant DNA technology. This allowed for the production of insulin identical to that produced by the human pancreas. In 1981, Novo Nordisk chemically and enzymatically converted porcine insulin into human insulin. Genentech's synthetic human insulin, produced in partnership with Eli Lilly, was approved by the U.S. Food and Drug Administration in 1982.
== Regulatory compliance == The European Commission has published harmonized rules on supplement products to assure consumers have minimal health risks from using dietary supplements and are not misled by advertising. In the United States and Canada, dietary supplements are considered a subset of foods, and are regulated accordingly. The U.S. Food and Drug Administration (FDA) monitors supplement products for accuracy in advertising and labeling. Dietary supplements are regulated by the FDA as food products subject to compliance with current Good Manufacturing Practices (CGMP) and labeling with science-based ingredient descriptions and advertising. When finding CGMP or advertising violations, FDA warning letters are used to notify manufacturers of impending enforcement action, including search and seizure, injunction, and financial penalties. Examples between 2016 and 2018 of CGMP and advertising violations by dietary supplement manufacturers included several with illegal compositions or advertising of vitamins and minerals. The U.S. Federal Trade Commission, which litigates against deceptive advertising in marketed products, established a consumer center to assist reports of false health claims in product advertising for dietary supplements. In 2017, the FTC successfully sued nine manufacturers for deceptive advertising of dietary supplements.
==== Niche uses ==== There are thousands of uses of various potassium compounds. One example is potassium superoxide, KO2, an orange solid that acts as a portable source of oxygen and a carbon dioxide absorber. It is widely used in respiration systems in mines, submarines and spacecraft as it takes less volume than the gaseous oxygen.
Sources: en.wikipedia.org
== Expanded Tag/Catcher pairs == Before the development of SpyTag/SpyCatcher, the pair Isopeptag/Pilin-C was created from protein Spy0128 of Streptococcus pyogenes. Following SpyTag/SpyCatcher, the fully orthogonal pair SnoopTag/SnoopCatcher was developed from the RrgA protein of Streptococcus pneumoniae that has no cross-reactivity with SpyTag/SpyCatcher. Note that SnoopTag/SnoopCatcher forms an isopeptide bond between a Lys-Asn instead of Lys-Asp found in SpyTag/SpyCatcher. The same domain from RrgA has now been split in a different way to that used to create SnoopTag/SnoopCatcher, with the new pair called DogTag/DogCatcher. Unlike SpyTag and SnoopTag which have extended structures, the region of RrgA used to create DogTag forms a β-hairpin and so predisposed for successful insertion into protein loops. This ability has been successfully exploited to fluorescently label an internal loop of the mammalian TRPC5 membrane channel protein which cannot be modified at the protein termini, without impacting on the channel properties of TRPC5. DogTag has been successful coupled to DogCatcher when inserted into soluble proteins (superfolder GFP, HaloTag, and Gre2p). The pair SdyTag/SdyCatcher was also developed in the same year from Streptococcus dysgalactiae fibronectin-binding protein CnaB domain, but since the protein has sequence similarity to the parent protein where SpyTag/SpyCatcher is derived from, SdyTag/SdyCatcher has cross-reactivity with SpyTag/SpyCatcher.
== Antidote == In case of a bite from the black mamba, the victim should be treated according to a standard protocol. The most important part of this treatment is the intravenous injection of a polyvalent antivenom. South African Vaccine Producers produces this antivenom. Polyvalent means that it can be used for different snakebites: vipers, mambas and cobras. Large quantities of the antivenom must be injected to counter the effects of the venom. The polyvalent antivenin is produced by injecting horses with adapted venom. The venom is first detoxified to prevent too much damage and death. This is mostly done by complexing the venom with an aldehyde like formalin. The venom is also administered with an adjuvant, like aluminium hydroxide or sodium alginate, to stimulate the immunological response. When the venom is injected, the body will produce antibodies. These will bind components – the variability of peptides – of the venom, which prevent further activity of the molecule and are ultimately removed by the immune system of the body. These antibodies are collected and purified from the blood and then packaged in mostly a liquid form. Horses are used because of the large blood volume. The final antivenom product expires after 5 years and needs to preferentially be kept cool, 4-8 °C. It can, however, survive different environmental situations for some weeks to months, without losing its potency. Because several venoms of different snakes are injected over time, the horse will develop different antibodies against all the venoms.
=== 7 May === The SBU announced that it had foiled a Russian plot to assassinate Zelenskyy and several senior Ukrainian military leaders and arrested two Ukrainian government protection unit colonels on suspicion of involvement. One person was killed by Russian shelling in Sumy Oblast. Russian-installed officials in Luhansk claimed that five people were injured in a fire caused by a Ukrainian missile strike on an oil depot. Ukrainian media reported that the HUR carried out a cyberattack on the Russian software firm 1C Company.
In 1968, they produced the first amino acid analyzer in the world, the JLC-5AH. The company also continued to develop its line of electron microscopes. The JEM-7, in 1964, was the first electronic microscope to include a mechanism for the electrical adjustment of the lens axis. The JEM-100B incorporated an electromagnetic deflection unit as well as an electromagnetic stigmator. The first photomicrograph of atomic arrangement in the world was taken by a JEOL electron microscope, in 1976. Kazuo Ito has expressed the company's philosophy as follows:
== Patents == Although details have not surfaced, it appears that the University of Utah forced the 23 March 1989 Fleischmann and Pons announcement to establish priority over the discovery and its patents before the joint publication with Jones. The Massachusetts Institute of Technology (MIT) announced on 12 April 1989 that it had applied for its own patents based on theoretical work of one of its researchers, Peter L. Hagelstein, who had been sending papers to journals from 5 to 12 April. An MIT graduate student applied for a patent but was reportedly rejected by the USPTO in part by the citation of the "negative" MIT Plasma Fusion Center's cold fusion experiment of 1989. On 2 December 1993 the University of Utah licensed all its cold fusion patents to ENECO, a new company created to profit from cold fusion discoveries, and in March 1998 it said that it would no longer defend its patents. The U.S. Patent and Trademark Office (USPTO) now rejects patents claiming cold fusion. Esther Kepplinger, the deputy commissioner of patents in 2004, said that this was done using the same argument as with perpetual motion machines: that they do not work. Patent applications are required to show that the invention is "useful", and this utility is dependent on the invention's ability to function.
Sources: en.wikipedia.org
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.
No national medicines agency has approved melanotan-2 for clinical use. Afamelanotide, a related but distinct peptide, holds a marketing authorisation in the European Union for a rare photosensitivity disorder. Melanotan-2 itself is handled as a laboratory chemical.
Its broad activity across melanocortin receptors makes it a tool for probing pigmentation, appetite and vascular signalling. Early trials recorded skin darkening and other effects that were not the original focus of the work. Those observations generated hypotheses that later studies have examined.
It is a synthetic cyclic heptapeptide and an analogue of alpha-melanocyte-stimulating hormone. The molecule is produced by chemical synthesis rather than extracted from a biological source.