The short version of alpha-MSH analogue fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-09-28 and is reviewed periodically as new material appears.
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controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports.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.
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 |
|---|---|---|
| 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 |
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.
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.
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.
=== Biosynthesis === Formic acid is named after ants which have high concentrations of the compound in their venom, derived from serine through a 5,10-methenyltetrahydrofolate intermediate. The conjugate base of formic acid, formate, also occurs widely in nature. An assay for formic acid in body fluids, designed for determination of formate after methanol poisoning, is based on the reaction of formate with bacterial formate dehydrogenase.
On the review aggregator website Rotten Tomatoes, 83% critics' reviews are positive, based on 6 reviews. The website's consensus reads: "Summoning fan favorites and new terrors for a chilling 13th installment; light your candles and prepare for a supreme surprise." Slate's J. Bryan Lowder deemed the season a "relieving return to form", adding "the writers have finally tuned back into the mix of camp and the grotesque that made the golden era so good". Michel Ghanem of TheWrap called the season a "beautifully puzzling ode to superfans". He highlighted the performance of Jessica Lange, calling her "as good as ever, scene-stealing through snippy lines and entertaining monologues, brightening up a slow start to the season". Writing for Radio Times, Louise Griffin deemed it "hellishly flawed but still fiendishly fun", feeling that the series "has reached its pinnacle – not, certainly, in quality, but in terms of pure spectacle". Similarly, she highlited Lange, commenting: "it's a delight to once again relish in the devilry of one of [the series'] best creations." Vulture's Jen Chaney felt that watching the season "feels more than ever like being stuck in some sort of hell", arguing it delivered the "most incoherent debut in [the series'] decade-plus of existence". However, she praised Lange, opining she "lends some stability to this narratively shaky material through her performance".
== Properties == While most bacteriocins generally inhibit only closely related species, nisin is a rare example of a "broad-spectrum" bacteriocin effective against many Gram-positive organisms, including lactic acid bacteria (commonly associated with avoiding food spoilage), Listeria monocytogenes (a known pathogen), Staphylococcus aureus, Bacillus cereus, Clostridium botulinum, etc. It is also particularly effective against spores. Gram-negative bacteria are protected by their outer membrane but may become susceptible to nisin action after a heat shock or when this is coupled with the chelator EDTA. When used in combination with EDTA, nisin can inhibit E. coli O157:H7 and Salmonella enterica. Nisin, as a class I bacteriocin, is very stable at acidic pHs and is more heat stable at lower pHs. The mode of action of Nisin against pathogens such as Listeria monocytogenes is to dissipate the membrane potential and pH gradient. Nisin is soluble in water and effective at levels nearing the parts-per-billion range. Nisin concentration can be measured using various techniques such as chromatography or by a simple agar diffusion bioassay.
In a meta-analysis of various trials involving fluoxetine (Prozac), fluvoxamine (Faverin/Luvox), and sertraline (Zoloft) to test their relative efficacies in treating OCD, clomipramine was found to be significantly more effective. Other studies have borne similar results even when risk of bias is eliminated. A potentially significantly greater inherent side-effect profile, however, makes it a second-line choice in the treatment of OCD. SSRIs are generally better-tolerated but appear to be inferior in terms of actual clinical efficacy.
Sources: en.wikipedia.org
The first patch for the Xbox 360 version was released about two weeks after release to fix some of the game stability issues players had reported. The patch was found to introduce more problems to the game for some users, including occasional freezes, bad framerates, and audio-related issues, though methods to resolve these issues through the console's cache system were outlined by Irrational Games. In December 2007, a common patch was released for both the Xbox 360 and Windows version. The patch included additional content such as new Plasmids, new achievements for the Xbox 360 version, and a FOV lock that allowed widescreen players a wider field of view without losing vertical information. The patch also added in an option to disable the use of Vita-Chambers, a feature requested by players to make the game more challenging, as well as an achievement to complete the game at its hardest setting without using a Vita-Chamber. In 2014, 2K Games released a DRM-free version of BioShock in the Humble 2K Bundle, followed by DRM-free releases on GOG in 2018.
==== Learning ==== Since the seminal studies of Charles Darwin on earthworm intelligence much work has been done on the capacity of earthworms, in particular members of the widespread Lumbricus terrestris, to learn, although some doubts were raised about the use of T-maze experiments for demonstrating learning by earthworms.
It may also be possible to generate isotopes in the island of stability such as 298Fl in multi-nucleon transfer reactions in low-energy collisions of actinide nuclei (such as 238U and 248Cm). This inverse quasifission (partial fusion followed by fission, with a shift away from mass equilibrium that results in more asymmetric products) mechanism may provide a path to the island of stability if shell effects around Z = 114 are sufficiently strong, though lighter elements such as nobelium and seaborgium (Z = 102–106) are predicted to have higher yields. Preliminary studies of the 238U + 238U and 238U + 248Cm transfer reactions have failed to produce elements heavier than mendelevium (Z = 101), though the increased yield in the latter reaction suggests that the use of even heavier targets such as 254Es (if available) may enable production of superheavy elements. This result is supported by a later calculation suggesting that the yield of superheavy nuclides (with Z ≤ 109) will likely be higher in transfer reactions using heavier targets. A 2018 study of the 238U + 232Th reaction at the Texas A&M Cyclotron Institute by Sara Wuenschel et al. found several unknown alpha decays that may possibly be attributed to new, neutron-rich isotopes of superheavy elements with 104 < Z < 116, though further research is required to unambiguously determine the atomic number of the products. This result strongly suggests that shell effects have a significant influence on cross sections, and that the island of stability could possibly be reached in future experiments with transfer reactions.
Jainism teaches vegetarianism as moral conduct, as do some sects of Hinduism. Buddhism in general does not prohibit meat eating, but Mahayana Buddhism encourages vegetarianism as beneficial for developing compassion. Other denominations that advocate a vegetarian diet include the Seventh-day Adventists, the Rastafari movement, the Ananda Marga movement and the Hare Krishnas. Sikhism does not equate spirituality with diet and does not specify a vegetarian or meat diet.
Charleys Cheesesteaks, officially Charleys Philly Steaks, is an American restaurant chain specializing in Philly cheesesteak headquartered in Columbus, Ohio. Formerly known as Charley's Steakery and Charley's Grilled Subs, the franchise was established in 1986 on the campus of Ohio State University. By 2017 there were 600 locations in 45 states and in 19 countries. Charleys is believed to have doubled in size in 2021. In addition to traditional Philly cheesesteaks, the chain also has other steak based sandwiches and multiple grilled chicken sandwiches, among other grilled sandwiches.
Sources: en.wikipedia.org
=== Autoimmune diseases === Monoclonal antibodies used for autoimmune diseases include infliximab and adalimumab, which are effective in rheumatoid arthritis, Crohn's disease and ulcerative colitis by their ability to bind to and inhibit TNF-α. Basiliximab and daclizumab inhibit IL-2 on activated T cells and thereby help preventing acute rejection of kidney transplants. Omalizumab inhibits human immunoglobulin E (IgE) and is useful in moderate-to-severe allergic asthma.
== Function == This gene, expressed in the pituitary, encodes a receptor for growth-hormone-releasing hormone. Binding of this hormone to the receptor leads to synthesis and release of growth hormone. Mutations in this gene have been associated with isolated growth-hormone deficiency (IGHD), also known as Dwarfism of Sindh, a disorder characterized by short stature. Many alternate transcriptional splice variants encoding different isoforms have been described, but only two have been characterized to date.
The Federal Republic of Yugoslavia was a union between Serbia and Montenegro which had existed between 1992 and 2003. It was reconstituted as the State Union of Serbia and Montenegro in 2003. In 2006, the state broke up into the two independent states of Serbia and Montenegro.
== Homology == Several organisms possess multiple CPA2 paralogues. Thus, E. coli has three, Methanococcus jannaschii has four and Synechocystis sp. has five paralogues. The potassium efflux system, Kef, protects bacteria against the detrimental effects of electrophilic compounds via acidification of the cytoplasm. Kef is inhibited by glutathione (GSH) but activated by glutathione-S-conjugates (GS-X) formed in the presence of electrophiles. GSH and GS-X bind to overlapping sites on Kef, which are located in a cytosolic regulatory domain.
tRFs are not restricted to humans and have been shown to exist in multiple organisms. Two online tools are available for those wishing to learn more about tRFs: the framework for the interactive exploration of mitochondrial and nuclear tRNA fragments (MINTbase) and the relational database of Transfer RNA related Fragments (tRFdb Archived 2024-03-15 at the Wayback Machine). MINTbase also provides a naming scheme for the naming of tRFs called tRF-license plates (or MINTcodes) that is genome independent; the scheme compresses an RNA sequence into a shorter string.
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.
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.