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 2026-07-18. Numbers and descriptions here follow the published literature rather than marketing material.
Routine characterisation relies on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, using a C18 column and a water-acetonitrile gradient containing trifluoroacetic acid. Electrospray ionisation mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidised by-products that co-elute poorly. Sequence and stereochemistry require additional work, such as peptide mapping or amino acid analysis, because a chromatographic purity figure alone does not distinguish a diastereomer from the target peptide. Independent testing of research-grade material frequently shows measured content below the stated label, so a certificate of analysis is best read together with the method that produced it.
Melanotan-2 is handled in the laboratory as a lyophilised powder that dissolves readily in water, dimethyl sulfoxide and dimethylformamide, with limited solubility in ethanol. Stock solutions prepared in an organic solvent often precipitate when diluted into aqueous buffer, so gradual dilution with mixing is standard practice. The peptide carries a tryptophan residue and a histidine residue, both sensitive to oxidation and to alkaline conditions. Working solutions are therefore kept near neutral to slightly acidic pH, protected from light, and consumed within the same working session whenever that is practical.
Solid peptide kept dry at minus twenty degrees Celsius, shielded from light and moisture, is generally considered stable for extended periods. Solutions are divided into single-use aliquots and held at minus twenty or minus eighty degrees Celsius, because repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. Hydrolysis of the backbone and oxidation of tryptophan are the principal degradation routes in aqueous solution, and both accelerate at ambient temperature. Hygroscopic uptake after a vial is opened can also shift the actual mass weighed, which affects any concentration calculated from it.
Two structural changes distinguish the synthetic peptide from the natural hormone. A norleucine residue replaces methionine at one position, and a D-configured phenylalanine replaces the natural L-form at another. Both substitutions slow enzymatic breakdown, which extends the molecule's persistence relative to the parent hormone. The lactam bridge further constrains the backbone into a stable conformation. These features are standard design strategies in peptide chemistry and are not unique to this compound; they appear across many research peptides built for improved stability.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilised material may be hygroscopic |
| Solubility class | Soluble in water, DMSO and DMF | Dilution into aqueous buffer can cause precipitation |
| Storage of solid | Minus 20 degrees C, desiccated, dark | Aliquot to limit repeated opening of the vial |
| Storage of solution | Minus 20 to minus 80 degrees C, aliquoted | Avoid repeated freeze-thaw cycles |
| Identity method | Reversed-phase HPLC with mass spectrometry | Retention time and mass are checked together |
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.
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.
The compound emerged from research programs in the 1980s that examined analogues of alpha-melanocyte-stimulating hormone for pigmentation and photoprotection. Investigators modified the native sequence to extend activity duration and potency. A related analogue, afamelanotide, was developed within the same broad line of inquiry and eventually gained approval in certain jurisdictions for a rare light-sensitivity condition. Melanotan-2 itself did not progress through the same regulatory route and has no approved therapeutic indication.
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.
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.
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.
=== 2011 Scottish Parliament election === In January 2011, Galloway launched his campaign in preparation of the May Scottish Parliament election, announcing that he would standing in the Glasgow region. Respect and Solidarity formed an alliance for the election, with Galloway being their top candidate in Glasgow. On the regional ballot, Respect-Solidarity polled 6,972 list votes (3.3%), failing to elect any candidates, though did finish ahead of the Liberal Democrats who lost their seat.
==== U.S. regulatory restrictions ==== The US Food and Drug Administration (FDA) position is that red yeast rice products that contain monacolin K are identical to a prescription drug and, thus, subject to regulation as a drug. In 1998, the FDA initiated action to ban a product (Cholestin) containing red yeast rice extract. The U.S. District Court in Utah ruled in favor of allowing the product to be sold without restriction. This decision was reversed on appeal to the U.S. Court of Appeals in 2001. In 2007, the FDA sent warning letters to two dietary supplement companies. One was making a monacolin content claim about its RYR product and the other was not, but the FDA noted that both products contained monacolins. Both products were withdrawn. In a press release the FDA "...is warning consumers to not buy or eat red yeast rice products... may contain an unauthorized drug that could be harmful to health." The rationale for "harmful to health" was that consumers might not understand that the dangers of monacolin-containing red yeast rice are the same as those of prescription statin drugs. A products analysis report from 2010 tested 12 products commercially available in the U.S. and reported that per 600 mg capsule, total monacolins content ranged from 0.31 to 11.15 mg. A 2017 study tested 28 brands of red yeast rice supplements purchased from U.S. retailers, stating "the quantity of monacolin K varied from none to prescription strength". Many of these avoid FDA regulation by not having any appreciable monacolin content.
This page, Glossary of cellular and molecular biology (0–L), lists terms beginning with numbers and with the letters A through L. Glossary of cellular and molecular biology (M–Z) lists terms beginning with the letters M through Z. This glossary is intended as introductory material for novices (for more specific and technical detail, see the article corresponding to each term). It has been designed as a companion to Glossary of genetics and evolutionary biology, which contains many overlapping and related terms; other related glossaries include Glossary of virology and Glossary of chemistry.
Molecular sequence analysis: With rapid development of DNA sequencing technology, an enormous amount of DNA sequence data is available and even more is forthcoming in the future. Various methods have been developed to infer the DFE from DNA sequence data. By examining DNA sequence differences within and between species, we are able to infer various characteristics of the DFE for neutral, deleterious and advantageous mutations. To be specific, the DNA sequence analysis approach allows us to estimate the effects of mutations with very small effects, which are hardly detectable through mutagenesis experiments. One of the earliest theoretical studies of the distribution of fitness effects was done by Motoo Kimura, an influential theoretical population geneticist. His neutral theory of molecular evolution proposes that most novel mutations will be highly deleterious, with a small fraction being neutral. A later proposal by Hiroshi Akashi proposed a bimodal model for the DFE, with modes centered around highly deleterious and neutral mutations. Both theories agree that the vast majority of novel mutations are neutral or deleterious and that advantageous mutations are rare, which has been supported by experimental results. One example is a study done on the DFE of random mutations in vesicular stomatitis virus. Out of all mutations, 39.6% were lethal, 31.2% were non-lethal deleterious, and 27.1% were neutral. Another example comes from a high throughput mutagenesis experiment with yeast.
Sources: en.wikipedia.org
== Bioengineering == Protein production, the generation of a pure protein Protein design, the design of new protein molecules from scratch Protein engineering, application of science, mathematics, and economics to the process of developing useful or valuable proteins
== External links == FDA Alert on Bextra withdrawal Large systematic review of adverse renal and arrhythmia risk of valdcoxib and other COX-2 inhibitors, JAMA 2006 Archived 2020-11-05 at the Wayback Machine
The most common adverse effects of Captopril, skin rash and loss of taste, are the same as caused by mercapto-containing penicillamine. Therefore, a group of researchers aimed at finding potent, selective ACE inhibitors that would not contain a mercapto (SH) function and would have a weaker chelating function. They returned to work with carboxyl compounds and started working with substituted N-carboxymethyl-dipeptides as a general structure (R-CHCOOH-A1-A2). According to previous research they assumed that cyclic imino acids would result in good potency if substituted on the carboxyl terminus of the dipeptide. Therefore, substituting A2 with proline gave good results. They also noted that according to the enzyme's specificity imino acids in the position next to the carboxyl terminus would not give a potent compound. By substituting R and A1 groups with hydrophobic and basic residues would give a potent compound. By substituting –NH in the general structure resulted in loss of potency which is consistent to the enzyme's need for a –NH in corresponding position on the substrates. The results were 2 active inhibitors: Enalaprilat and Lisinopril. These compounds both have phenylalanine in R position which occupies the S1 groove in the enzyme. The result was thus these two new, potent tripeptide analogues with zinc-coordinating carboxyl group: Enalaprilat and Lisinopril.
Sources: en.wikipedia.org
Overuse injuries of the musculoskeletal system because of repetitive exercise, with young athletes (under the age of 19) particularly at risk Overtraining syndrome may lead to persistent dysfunction of a number of body systems High volumes of training with insufficient calorie intake puts athletes—particularly female ones—at risk for RED-S Aerobic exercise may not be as time-efficient as other cardiovascular training methods. For example, High-intensity interval training (HIIT) has been shown to provide similar benefits in a fraction of the time spent exercising per week. Both the health benefits and the performance benefits, or "training effect", require that the duration and the frequency of exercise both exceed a certain minimum. Most authorities suggest at least twenty minutes performed at least three times per week.
The company began as a collaboration between a group of entrepreneurs, the professional artist Joseph Lyons and his brothers in law, Isidore and Montague Gluckstein, as a spin off from the Salmon & Gluckstein tobacco company. In 1894 the company started a teashop in Piccadilly, London, and from 1909 developed this into a chain of teashops which would ultimately number around 200 locations. The company also ran high class restaurants, founding the Trocadero in 1895, and hotels including the Strand Palace, opened in 1909, the Regent Palace, opened in 1915, and the Cumberland Hotel, opened in 1933, all in London. In 1918, to increase sales in northern England, Lyons bought the old established tea company Horniman & Sons. From the 1930s Lyons began to develop a pioneering range of teas, biscuits and cakes that were sold in grocery stores across the world. Lyons was appointed to run the company, and it was named after him. J. Lyons & Co. was a pioneer in introducing computers to business. Between 1951 and 1963, the company manufactured and sold a range of LEO (Lyons Electronic Office) computers.
=== Caffé Bene === Caffe Bene is a coffeehouse chain based in Seoul. It was founded in May 2008 by Sun-Kwon Kim, its chief executive officer. Caffè Bene is the largest coffeehouse in South Korea measured by number of stores. As of April 24, 2012, it had 760 outlets. Initially Caffe Bene struggled to gain any traction in an oversaturated American market. Failing to gain brand recognition, Sun-Kwon Kim agreed a deal with a number of entertainment shows to use his coffee locations in a selection of TV shows for a 3% share in the companies profit.
Sources: en.wikipedia.org
Purity is normally stated as an area percentage from high-performance liquid chromatography, for example ninety-five or ninety-eight percent. That figure describes the proportion of ultraviolet-absorbing material eluting as the main peak. It says nothing about water content, counterions, residual solvents or mass fraction of the peptide itself.
Peptides are commonly isolated as acetate or trifluoroacetate salts, and the counterion contributes to total mass. Two vials with identical peptide content can therefore differ in weight and in measured response. Residual trifluoroacetate is also relevant in cell-based work because it can influence membrane behaviour.
Degradation products are often closely related to the parent molecule, making them hard to resolve with a single method. Counterion variability adds a further source of scatter between laboratories. Because no pharmacopoeial monograph exists for melanotan-2, groups rely on method-specific validation rather than a shared reference standard.
It is a synthetic seven-amino-acid peptide modeled on alpha-melanocyte-stimulating hormone. It carries two non-natural substitutions and a cyclic bridge that increase its stability relative to the natural hormone. It circulates as a research chemical and is not an approved medicine.