Melanotan II is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-09-06. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| 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.
Mendelevium(II)'s elution behavior has been compared with that of strontium(II) and europium(II). In 1973, mendelevium(I) was reported to have been produced by Russian scientists, who obtained it by reducing higher oxidation states of mendelevium with samarium(II). It was found to be stable in neutral water–ethanol solution and be homologous to caesium(I). However, later experiments found no evidence for mendelevium(I) and found that mendelevium behaved like divalent elements when reduced, not like the monovalent alkali metals. Nevertheless, the Russian team conducted further studies on the thermodynamics of cocrystallizing mendelevium with alkali metal chlorides, and concluded that mendelevium(I) had formed and could form mixed crystals with divalent elements, thus cocrystallizing with them. The status of the +1 oxidation state is still tentative. The electrode potential E°(Md4+→Md3+) was predicted in 1975 to be +5.4 V; 1967 experiments with the strong oxidizing agent sodium bismuthate were unable to oxidize mendelevium(III) to mendelevium(IV).
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== Formats and the submission process == Since detailed proteomics data currently cannot be curated from the existing literature, the source of PRIDE data is solely submissions by academic researchers. PRIDE is a standards-compliant public repository, meaning that its own XML-based data exchange format for submissions, PRIDE XML, was built around the Proteomics Standards Initiative mzData standard for mass spectrometry. Recently, PRIDE has been adapted to work with the modern mzML and mzIdentML standards of the Proteomics Standards Initiative. An additional format, dubbed mzTab, can be used as a simplified way to submit quantitative proteomics data. As there are many types of different mass spectrometry instruments and software formats are currently on the market, wet-lab scientists without a strong bioinformatics background or informatics support were having problems converting their data to PRIDE XML. The development of PRIDE Converter helped to tackle this situation. PRIDE Converter is a tool, written in the Java programming language, that converts 15 different input mass spectrometry data formats into PRIDE XML via a wizard-like graphical user interface. It is freely available and is open source under the permissive Apache License. A new version of PRIDE Converter was released in 2012 as PRIDE Converter 2. This new version constituted a complete rewrite, focused on easy adaptability to different (and evolving) data sources.
As he further noted, China "has a much more developed manufacturing base than the old Soviet Union", making a Second Cold War "potentially more dangerous than the" original Cold War, and China's manufacturing capabilities have surpassed those of the US, which "has allowed its industrial base to be hollowed out over the years while supply chains splintered and moved overseas".
Sources: en.wikipedia.org
These ranged from deformed jaws to cyclopia. After decades of research, in the 1980s, the compound responsible for these deformities was identified as the alkaloid 11-deoxyjervine, later renamed to cyclopamine.
Despite the fearsome reputation, aggression toward humans usually only arises from an individual inadvertently exposing itself or being cornered; encounters happen through chance, including negative interactions. Threatened by habitat destruction, it has been listed as Vulnerable on the IUCN Red List since 2010. Regarded as the national reptile of India, it has an eminent position in the mythology and folk traditions of India, Bangladesh, Sri Lanka and Myanmar.
Spelt, being closely related to bread wheat, is a likely source of alleles to increase wheat's genetic diversity, and so improve crop yields. Analysis of the Oberkulmer cultivar of spelt found 40 alleles that could contribute to increased yield. Among the differences were spelt's larger grain size, greater fertility of tillers, and longer fruiting spikes. Pm5 is an effector-triggered resistance gene for powdery mildew.
strongly acidic cation (SAC), typically featuring sulfonic acid groups, e.g. sodium polystyrene sulfonate or polyAMPS, often used for water softening and demineralization operations. strongly basic anion (SBA), typically featuring quaternary amino groups, for example, trimethylammonium groups, e.g. polyAPTAC), good for silica, uranium, nitrates removal. weakly acidic cation (WAC), typically featuring carboxylic acid groups. An ideal choice for dealkalization part and also for softening streams with high salinity levels. weakly basic anion (WBA), typically featuring primary, secondary, and/or tertiary amino groups, e.g. polyethylene amine. Are effective for demineralization where removal of SiO2 and CO2 are not required. Also effective for acid absorption. Specialised ion-exchange resins are also known such as chelating resins (iminodiacetic acid, thiourea-based resins, and many others). Anion resins and cation resins are the two most common resins used in the ion-exchange process. While anion resins attract negatively charged ions, cation resins attract positively charged ions.
Up to this point, Counterparts and Test for Echo were two of Rush's most guitar-driven albums. The latter album also includes elements of jazz and swing-style drumming by Peart, which he had learned from drum coach Freddie Gruber during the interim between Counterparts and Test for Echo. "Stick It Out" from Counterparts reached the summit of the US Mainstream Rock Tracks Chart, with the album peaking at No. 2 in the US and No. 6 in Canada. Test for Echo reached the Top 5 in both countries, with the title track again topping the US Mainstream Rock Tracks Chart. In October 1996, in support of Test For Echo, the band embarked on a North American tour, the band's first without an opening act and dubbed "An Evening with Rush". The tour was broken into two segments, spanning October through December 1996 and May through July 1997. After the conclusion of the Test for Echo tour in 1997, the band entered a five-year hiatus primarily due to personal tragedies in Peart's life. Peart's daughter Selena died in a car crash in August 1997, and his wife Jacqueline died of cancer in June 1998. Peart went on hiatus to mourn and reflect. During that time, he travelled extensively throughout North America on his BMW motorcycle, covering 88,000 km (55,000 mi). In his book Ghost Rider: Travels on the Healing Road, Peart writes of how he had told his bandmates at Selena's funeral, "consider me retired." This left the band's future uncertain, and Lee and Lifeson prepared an archival album, Different Stages, for release during the hiatus.
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.