The short version of Melanotan II fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-09-01. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Compound class | Synthetic cyclic heptapeptide | Alpha-MSH analogue containing a D-phenylalanine residue |
| Molecular formula | C50H69N15O9 | Average molecular mass approximately 1024.2 g/mol |
| Appearance | White to off-white lyophilised powder | Normally supplied as a freeze-dried solid in a sealed vial |
| Solubility | Freely soluble in water and polar solvents | Dissolves readily in aqueous buffers and in alcohol-water mixtures |
| Receptor targets | MC1R, MC3R, MC4R, MC5R | Acts as a non-selective melanocortin receptor agonist |
Outside regulated medicine, melanotan II circulates through online vendors as a research chemical, often marketed for tanning. Products sold this way vary widely in purity, concentration, and labeling accuracy, and independent testing has documented discrepancies. Published reports describe both pigment effects and adverse reactions, including nausea, flushing, and darkening of existing moles. Long-term safety data are sparse, and no large controlled trial has established a risk profile. Questions about cumulative effects on melanocytes remain unresolved in the literature.
Melanotan II is a synthetic peptide analog modeled on alpha-melanocyte-stimulating hormone, a naturally occurring signaling peptide involved in pigmentation. Its structure is a cyclic heptapeptide containing two non-natural substitutions, norleucine at position four and D-phenylalanine at position seven. These modifications resist enzymatic breakdown and extend the molecule's activity relative to the native hormone. The compound binds melanocortin receptors and is studied mainly as a pharmacological tool rather than a therapeutic product. It has never received approval as a medicine in any major jurisdiction.
The compound was developed in the late 1980s and 1990s by academic researchers investigating photoprotection. The rationale held that stimulating melanin production might reduce ultraviolet damage to skin and lower skin cancer risk. Early work examined receptor binding, pigment response, and short-term tolerability in small studies. That program did not produce an approved drug, and formal development stalled after early-phase trials. Whether induced pigmentation confers meaningful photoprotection remains an open question.
The laminae of the thyroid cartilage: two leaf-like plates of cartilage that make up the walls of the structure. The vertebral laminae: plates of bone that form the posterior walls of each vertebra, enclosing the spinal cord. The laminae of the thalamus: the layers of thalamus tissue. The lamina propria: a connective tissue layer under the epithelium of an organ. The nuclear lamina: a dense fiber network inside the nucleus of cells. The lamina affixa: a layer of epithelium growing on the surface of the thalamus. The lamina of Drosophila is the most peripheral neuropil of the insect visual system. Lamina cribrosa with two different meanings. Osseous spiral lamina, a feature of the bony canal of the cochlea
== Prognosis == The prognosis is best when identified early and treated aggressively. In earlier studies the mortality rates of NMS ranged from 20%–38%, but by 2009 mortality rates were reported to have fallen below 10% over the previous two decades due to early recognition and improvements in management. Re-introduction of antipsychotics after NMS may trigger a recurrence, although in most cases it does not. With recurrence rate being 4.2% in a small, population based study.
C3S: alite (3CaO·SiO2); C2S: belite (2CaO·SiO2); C3A: tricalcium aluminate (3CaO·Al2O3) (historically, and still occasionally, called celite); C4AF: Calcium aluminoferrite (4CaO·Al2O3·Fe2O3). The silicates are responsible for the cement's mechanical properties — the tricalcium aluminate and brownmillerite are essential for the formation of the liquid phase during the sintering (firing) process of clinker at high temperature in the kiln. The chemistry of these reactions is not completely clear and is still the object of research. First, the limestone (calcium carbonate) is burned to remove its carbon, producing lime (calcium oxide) in what is known as a calcination reaction. This single chemical reaction is a major emitter of global carbon dioxide emissions.
=== Silicon batteries === The company started promoting its silicon-graphite-electrode batteries in 2019 and ceased development of its germanium-based batteries in 2020. The company sent germanium sample batteries to manufacturers in place of silicon sample batteries. The company's CEO said the germanium batteries were only developed as proof-of-concept, were only meant to be sold in small quantities, and that they were never released because they weren't sufficiently differentiated from the rest of the market. Group14 Technologies has developed silicon nanoparticles called SCC55 which allow lithium-silicon batteries to charge from 10% to 80% state-of-charge in 10 minutes. StoreDot tested the material for use in their silicon batteries. The company was looking in 2023 for suppliers capable of manufacturing thousands of tonnes of this material, which is critical for their business. The battery cells have a sponge-like carbon electrode imbued with silicon nanoparticles that react with the lithium ions, keeping the silicon's expansion within the carbon "sponge".
Sources: en.wikipedia.org
=== 2022: In the Court of the Crimson King documentary; end of band activity === Following the band's 2021 tour dates, King Crimson ceased activity without expressly announcing a breakup. Fripp cited practical reasons for concluding the band's touring career, such as the old age of several of the members and the rising cost of services during the COVID-19 pandemic. On 9 February 2022, founding King Crimson member Ian McDonald died of cancer. In March 2022, the documentary film In the Court of the Crimson King was premiered at the 2022 SXSW Film Festival. Directed by Toby Amies and filmed between 2019 and 2021, it covered live and backstage activity by the then-current band but also featured a historical overview plus contributions from Crimson alumni Ian McDonald, Michael Giles, Bill Bruford, Adrian Belew and Trey Gunn (as well as prolonged interview footage with the late Bill Rieflin). Amies described the film's development as follows: "What began as a traditional documentary about the legendary band King Crimson as it turned fifty, mutated into an exploration of time, death, family, and the transcendent power of music to change lives; but with jokes." As of 2022, no King Crimson activity was planned for the future, excepting ongoing archive/curatorial matters. Levin said in a late 2022 interview that "the sense I got from Robert [Fripp] was that it's over.
An internet service provider has been held to be an ISS, and so has a Wi-Fi host, the Electronic Commerce Directive 2000 recital 11 states email services, search engines, data storage, and streaming, are information society services, and an individual email is not, and the Information Society Directive 2015 makes clear that TV and radio stations do not count as ISS's. None of these definitions include advertising, which is never "at the request of a recipient of services" as the 2015 Directive requires, however various cases have decided that eBay, Facebook, and AirBnB, may count as ISSs, but the cab app Uber does not. The main rights to data privacy are found in the General Data Protection Regulation 2016. First, there is the right to have data about someone processed only with their 'consent', or based on other justifiable grounds, such as a lawful purpose. It has been held that consent is not given if there is 'a pre-checked checkbox which the user must deselect to refuse'. Under the Privacy and Electronic Communications Directive 2002 a well-known result is that websites must not install "cookies" into someone's web browser unless they positively accept cookies. The EU has not yet simply enabled people to block all cookies within a browser, and required that websites give people this option without thousands of annoying buttons to click. Second, people have the right to be informed about data kept on them. Third, there is a right to be forgotten and the data to be deleted.
=== Civil servants === The government increased by 9%, starting in May 2023, the remuneration of civil servants and civilian public employees of the Federal Executive Branch, with an estimated annual cost of about 14 billion reais, and increased by 200 reais the meal allowance paid to active servants and employees. Civil servants of the other branches received an increase at a higher rate (18%), staggered in three installments until 2025. The salary cap of the public service became 41,650 reais starting in April 2023, and will be 44,008 reais in February 2024 and 46,366 reais in February 2025. The federal government also created 665 new commissioned positions, with remuneration of up to 14,849 reais, and 1,578 commissioned functions, with compensation of up to 8,909 reais. Commissioned positions do not need to be occupied by career civil servants, unlike commissioned functions, which can only be occupied by those who are already public servants and which add the value of the function's compensation to the remuneration. The Concurso Público Nacional Unificado (CPNU), also called the Concurso Nacional Unificado (CNU), is an initiative of the Ministry of Management and Innovation in Public Services (MGI) of the Federal government of Brazil to centralize and streamline the process of hiring new federal civil servants.
Given the importance of the Kucha region in the transmission of Buddhism into China and the evidence we have about the movement of translators such as Kumarajiva, it is reasonable to suggest that the art (and possibly the artists) of Kizil influenced the early art of the Mogao Cave complex near Dunhuang, further east along the Silk Road. The earliest of the extant Dunhuang caves (dating from the beginning of the fifth century) show distinctly "Central Asian" features in their painting, stylistically similar to what we find at Kizil. Among the subjects depicted at Kizil and Mogao in strikingly similar fashion is that of the "Cosmological Buddha", whose robe displays images connected with the phenomenal world.
This term has become very popular and commonly used in practice. But the appropriate expression is "enantioselective chromatography". Chiral chromatography has advanced to turn into the most preferred technique for the determination of enantiomeric purity as well as separation of pure enantiomers both on analytical and preparative scale. Chiral chromatographic assay is the first step in any study pertaining to enantioselective synthesis or separation. This includes the use of techniques viz. gas chromatography (GC), high performance liquid chromatography (HPLC), chiral supercritical fluid chromatography (SFC), capillary electrophoresis (CE) and thin-layer chromatography (TLC). The result of a literature survey done identifies HPLC-based chiral assays as the most dominating technology in use. An overview of various analytical methods engaged for chiral separation and analysis are listed in the table.
Sources: en.wikipedia.org
In humans, FDC-SP was first found within follicular dendritic cell isolates from the tonsil, and later was found to be specifically expressed within the periodontal ligament. FDC-SP expression can be induced in human FDC-like cell lines by exposure to tumour necrosis factor (TNF). Exposure of human peripheral blood cells to LPS can also result in FDC-SP expression, but TNF exposure does not cause FDC-SP expression and similarly LPS exposure does not cause expression within FDC-like cell lines. Expression in mouse splenocytes can be induced by LPS in a similar manner to that of human peripheral blood cells. In mice, as in humans, FDC-SP is not expressed in B cells, but FDC-SP expression in FDCs can be dependent on B cells after their stimulation by CD40. After stimulation with CD40, B cells have been shown to be able to induce phenotypic changes in FDCs through the B cell's surface TNF expression. It has therefore been suggested that the expression of TNF cytokines by B cells causes FDC-SP expression within FDCs upon contact. This reaction is said to be typical during GC formation. FDC-SP is highly expressed in the junctional epithelium and well as in the tonsils, prostate, lymph nodes and trachea. The proline rich region in the C-terminal half bears some resemblance to the antimicrobial peptide Bac5. FDC-SP may therefore have a role in microbial defense in the oral cavity.
Chlorella vulgaris is a species of green microalga in the division Chlorophyta. This unicellular alga was discovered in 1890 by Martinus Willem Beijerinck as the first microalga with a well-defined nucleus. It is the type species of the genus Chlorella. It is found in freshwater and terrestrial habitats, and has a cosmopolitan distribution. Chlorella vulgaris has a number of potential applications in science, such as biofuel, livestock feed, and wastewater treatment. Beginning in the 1990s, German scientists noticed the high protein content of C. vulgaris and began to consider it as a new food source. Japan is currently the largest consumer of Chlorella, both for nutritional and therapeutic purposes, and it is used as a dietary supplement or protein-rich food additive in several countries worldwide. C. vulgaris is a green eukaryotic microalga. The cells are 4–10 μm in diameter, and are spherical. The chloroplast (chromatophore) is pea-green in color and cup-shaped, with a single pyrenoid.
=== Chemical === Roentgenium is the ninth member of the 6d series of transition metals. Calculations on its ionization potentials and atomic and ionic radii are similar to that of its lighter homologue gold, thus implying that roentgenium's basic properties will resemble those of the other group 11 elements, copper, silver, and gold; however, it is also predicted to show several differences from its lighter homologues. Roentgenium is predicted to be a noble metal. The standard electrode potential of 1.9 V for the Rg3+/Rg couple is greater than that of 1.5 V for the Au3+/Au couple. Roentgenium's predicted first ionization energy of 1020 kJ/mol almost matches that of the noble gas radon at 1037 kJ/mol. Its predicted second ionization energy, 2070 kJ/mol, is almost the same as that of silver. Based on the most stable oxidation states of the lighter group 11 elements, roentgenium is predicted to show stable +5 and +3 oxidation states, with a less stable +1 state. The +3 state is predicted to be the most stable. Roentgenium(III) is expected to be of comparable reactivity to gold(III), but should be more stable and form a larger variety of compounds. Gold also forms a somewhat stable −1 state due to relativistic effects, and it has been suggested roentgenium may do so as well: nevertheless, the electron affinity of roentgenium is expected to be around 1.6 eV (150 kJ/mol), significantly lower than gold's value of 2.3 eV (220 kJ/mol), so roentgenides may not be stable or even possible.
=== Non-intoxicating effects === Cannabidiol does not appear to have any intoxicating effects such as those caused by ∆9-THC in cannabis, but it is under preliminary research for its possible anxiolytic and antipsychotic effects. As the legal landscape and understanding about the differences in medical cannabinoids unfolds, experts are working to distinguish "medical cannabis" (with varying degrees of psychotropic effects and deficits in executive function) from "medical CBD therapies", which would commonly present as having a reduced or non-psychoactive side-effect profile. Various strains of "medical cannabis" are found to have a significant variation in the ratios of CBD-to-THC and are known to contain other non-psychotropic cannabinoids. Any psychoactive cannabis, regardless of its CBD content, is derived from the flower (or bud) of the genus Cannabis. As defined by US federal law, non-psychoactive hemp (also commonly termed "industrial hemp"), regardless of its CBD content, is any part of the cannabis plant, whether growing or not, containing a ∆9-tetrahydrocannabinol concentration of no more than 0.3% on a dry-weight basis. In the United States, certain standards are required for legal growing, cultivating, and producing the hemp plant, but there are no federal standards for quality being enforced in the hemp industry. Certain state regulations are in place, but vary state to state. For instance, the Colorado Industrial Hemp Program registers growers of industrial hemp and samples crops to verify that the dry-weight THC concentration does not exceed 0.3%.
Sources: en.wikipedia.org
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.
No approved regulatory indication exists in major markets. An approval exists for a different peptide, afamelanotide, which is used for a rare photosensitivity disorder called erythropoietic protoporphyria. Melanotan-2 itself remains a research compound with no cleared clinical role.
Melanocortin-1 receptors on melanocytes are the receptor most closely linked to pigment production. The peptide is not selective, however, and also activates melanocortin-3, melanocortin-4, and melanocortin-5 receptors. That lack of selectivity is the usual explanation offered for both its range of observed effects and its off-target effects.
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.