If you have been reading about Melanotan II 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.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Melanotan-2 appears on the World Anti-Doping Agency prohibited list within the peptide hormone class, and several national regulators treat it as an unapproved prescription substance. Some countries restrict importation or sale for personal use. Because the compound is widely traded as a research chemical, the practical legal picture differs between jurisdictions and shifts over time. Human safety data covering long periods are limited, and whether repeated pigmentation changes carry any lasting risk to melanocytes remains an open question.
Freeze-dried melanotan-2 is normally kept as a desiccated powder at minus twenty degrees Celsius or lower, shielded from light and moisture. Peptides of this size degrade through hydrolysis, oxidation and deamidation, and each pathway accelerates as temperature and water activity rise. Repeated freeze-thaw cycles promote aggregation and loss of material, so aliquoting a stock solution before freezing is standard laboratory practice. Once dissolved, the solution is markedly less stable than the powder. In laboratory work, solutions are generally refrigerated and used within days rather than kept for months.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or oxidised impurities. Mass spectrometry, most often coupled to liquid chromatography, confirms molecular mass and detects substitutions that chromatography alone may miss. Amino acid analysis and peptide mapping supply additional structural evidence, while nuclear magnetic resonance is reserved for full structural confirmation. Laboratories that examine samples sold online report wide variation in actual content, with some vials containing little or none of the labelled material.
Human data remain limited and mostly short-term. Reports describe small trials and observational accounts rather than large controlled studies, so questions about dose-response relationships and long-term effects on melanocytes stay open. Whether repeated exposure alters naevus behaviour is not settled in the published record. Researchers also note that self-administered use outside clinical settings makes actual exposure difficult to quantify. Statements about efficacy and safety should therefore be read as preliminary rather than established.
Melanotan II is a synthetic cyclic heptapeptide that acts as an agonist at melanocortin receptors. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous peptide involved in pigment production. The analogue carries a lactam bridge that constrains the ring and slows enzymatic breakdown relative to the native hormone. In research literature it appears under several abbreviations, and naming conventions are not fully standardized. Published descriptions usually place it within the broader melanocortin agonist family.
Receptor binding at MC1R on melanocytes raises intracellular cyclic AMP and increases expression of tyrosinase and related enzymes. The downstream result is greater synthesis of eumelanin, the dark pigment, without ultraviolet exposure acting as the trigger. The compound is not selective, however, and also engages MC3R, MC4R and MC5R, which are expressed in the central nervous system and elsewhere. That lack of selectivity is the explanation usually offered for effects reported outside pigmentation, including appetite suppression and nausea. Selectivity remains a central theme in comparative studies of related peptides.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C or below | For the lyophilised powder, desiccated |
| Storage form | Sealed vial, protected from light | Amber glass or foil-wrapped containers |
| Reconstituted stability | Short, refrigerate | Degradation accelerates in solution |
| Typical analytical method | Reversed-phase HPLC with mass spectrometry | Purity assessment plus identity confirmation |
| Common synonyms | Melanotan II, MT-II | Also written melanotan-2 |
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.
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.
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.
Scientific discussion of Melanotan-2 spans pharmacology, dermatology, and public-health literature. Laboratory studies examine its receptor binding and cellular effects, while clinical reports describe outcomes observed after unregulated use. These two bodies of work differ in rigour and intent. Peer-reviewed trials of the compound as a medicine are limited, so much of the available information comes from case reports and surveillance data. Authors frequently note the gap between experimental findings and real-world use.
Reported observations after unregulated use include shifts in skin pigmentation and, in some accounts, unintended changes to moles and other lesions. Whether these outcomes are causally linked to the compound, and how often they occur, remain open questions because controlled data are scarce. The absence of standardised dosing and verified product purity complicates interpretation. Researchers have called for better surveillance and analytical characterisation of samples obtained outside regulated channels. Conclusions drawn from anecdotal evidence should be treated as provisional.
Melanotan-2 has not received marketing authorisation from major regulatory agencies for any therapeutic indication. Several jurisdictions classify it as a prescription-only medicine or a controlled substance when supplied for human use. Because approved products do not exist, material sold online usually sits outside pharmaceutical supply chains and formal quality oversight. Regulators have issued public notices describing the compound as unapproved. Enforcement varies, and the legal position differs between countries, which complicates any single general statement about its status.
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.
=== Pharmacodynamics === Unlike benzodiazepines, etifoxine may produce its anxiolytic effects through a dual mechanism, by directly binding to GABAA receptors and (purportedly, exact binding site undetermined) to the mitochondrial translocator protein (TSPO). This results in stimulation of the biosynthesis of endogenous neurosteroids, for instance allopregnanolone, a highly potent GABAA receptor positive allosteric modulator. At GABAA receptors etifoxine binds at the α+β− interface and preferentially potentiates α2β3γ2 and α3β3γ2 receptor types. This direct allosteric potentiation can only be observed at relatively high concentrations (starting at >1 mM) and is perhaps not physiologically relevant at normal human doses. This is different from benzodiazepines and etifoxine can be used alongside benzodiazepines to potentiate their effects without competing for binding sites; however, it also means that the direct effects of etifoxine are not reversed by the benzodiazepine antagonist flumazenil.
==== Novel agents ==== Several newer agents, including temozolomide and bendamustine, have activity in relapsed SCLC. Of note, temozolomide yielded a response rate of 38% for brain metastases due to SCLC. In a clinical trial of 50 patients, a combination of olaparib and temozolomide in relapsed small-cell lung cancer yielded an overall response rate of 41.7%, median progression-free survival of 4.2 months, and overall survival was 8.5 months. Lurbinectedin showed an increased overall survival rate in relapsed small cell lung cancer in a trial. Lurbinectedin is As of 2019 available in the U.S. under an expanded access program (EAP). Trilaciclib, a CKD4/6 inhibitor, reduces chemotherapy-induced toxicity in patients being treated for small-cell lung cancer. In 2021, the FDA approved trilaciclib (Cosela) as a treatment to reduce the frequency of chemotherapy-induced myelosuppression for patients receiving certain types of chemotherapy for extensive-stage small-cell lung cancer.
When the Legion of Merit is awarded to members of the Armed Forces of the United States, it is awarded without reference to degree. However, the medal and ribbon of the fourth degree (Legionnaire) are used for members of the Armed Forces of the United States. The US Army and US Air Force do not authorize the "V" Device for the Legion of Merit. The U.S. Navy, the U.S. Marine Corps, and the United States Coast Guard do. The first U.S. Armed Forces recipient of the Legion of Merit medal was World War II combat veteran Lieutenant, junior grade, Ann Bernatitus, U.S.N., one of the "Angels of Bataan" and the only U.S. Navy nurse to escape from Bataan and Corregidor during the war. She was also the first person authorized to wear the "V" Device with the award. Her medal is now housed at the Smithsonian Institution.
The School of Engineering offers Accreditation Board for Engineering and Technology (ABET) accredited degrees in engineering and admitted its first class starting in 1984. The first graduates received degrees in 1988. Eugene M. DeLoatch (retired 2016) was the first Dean of the School of Engineering, having previously been Chairman of the Department of Electrical Engineering at Howard University. He was succeeded by Michael G. Spencer who was previously a professor of electrical engineering at Cornell University. By 1991, the construction of the 35,000 sq ft (3,300 m2) Clarence M. Mitchell, Jr. School of Engineering building was completed, and the facility included sixteen teaching laboratories and five research laboratories. The William Donald Schaefer Building is a 40,000 sq ft (3,700 m2) addition to the Engineering School and was completed in April 1998. The facility provided instructional laboratories, classrooms, a student lounge, research laboratories and a 2,200 sq ft (200 m2) library annex. In 2015 Morgan State University's School of Engineering graduates provided more than two-thirds of the state's African-American Civil Engineers, 60 percent of the African-American Electrical Engineers, 80 percent of the African-American Telecommunications specialists, more than one-third of the African-American Mathematicians, and all of Maryland's Industrial Engineers.
Only five stable nuclides contain both an odd number of protons and an odd number of neutrons. The first four "odd-odd" nuclides occur in low mass nuclides, for which changing a proton to a neutron or vice versa would lead to a very lopsided proton-neutron ratio (21H, 63Li, 105B, and 147N; spins 1, 1, 3, 1). The only other entirely "stable" odd-odd nuclide, 180m73Ta (spin 9), is thought to be the rarest of the 251 stable nuclides, and is the only primordial nuclear isomer, which has not yet been observed to decay despite experimental attempts. Many odd-odd radionuclides (such as the ground state of tantalum-180) with comparatively short half-lives are known. Usually, they beta-decay to their nearby even-even isobars that have paired protons and paired neutrons. Of the nine primordial odd-odd nuclides (five stable and four radioactive with long half-lives), only 147N is the most common isotope of a common element. This is the case because it is a part of the CNO cycle. The nuclides 63Li and 105B are minority isotopes of elements that are themselves rare compared to other light elements, whereas the other six isotopes make up only a tiny percentage of the natural abundance of their elements.
Sources: en.wikipedia.org
Nicotinamide mononucleotide adenylyltransferase 1 (NMNAT1) is an enzyme that in humans is encoded by the nmnat1 gene. It is a member of the nicotinamide-nucleotide adenylyltransferases (NMNATs) which catalyze nicotinamide adenine dinucleotide (NAD) synthesis.
Protein tags are peptide sequences genetically grafted onto a recombinant protein. Tags are attached to proteins for various purposes. They can be added to either end of the target protein, so they are either C-terminus or N-terminus specific or are both C-terminus and N-terminus specific. Some tags are also inserted at sites within the protein of interest; they are known as internal tags. Affinity tags are appended to proteins so that they can be purified from their crude biological source using an affinity technique. Affinity tags include chitin binding protein (CBP), maltose binding protein (MBP), Strep-tag and glutathione-S-transferase (GST). The poly(His) tag is a widely used protein tag, which binds to matrices bearing immobilized metal ions. Solubilization tags are used, especially for recombinant proteins expressed in species such as E. coli, to assist in the proper folding in proteins and keep them from aggregating in inclusion bodies. These tags include thioredoxin (TRX) and poly(NANP). Some affinity tags have a dual role as a solubilization agent, such as MBP and GST. Chromatography tags are used to alter chromatographic properties of the protein to afford different resolution across a particular separation technique. Often, these consist of polyanionic amino acids, such as FLAG-tag or polyglutamate tag. Epitope tags are short peptide sequences which are chosen because high-affinity antibodies can be reliably produced in many different species. These are usually derived from viral genes, which explain their high immunoreactivity.
On February 19, 2019, Pritzker signed into law a bill that raises the state minimum wage to $15 an hour by 2025, making Illinois the fifth state in the nation and first state in the Midwest to do so. The bill includes a tax credit for small businesses to help them deal with higher costs of labor and maintains the ability of restaurant owners to count tips toward pay. On April 12, 2019, Pritzker signed the Collective Bargaining Freedom Act, which protects the right of employers, employees, and their labor organizations to collectively bargain, ensuring that Illinois complies with the National Labor Relations Act. On May 17, 2019, Pritzker signed legislation to help workers exposed to toxic substances. In July 2019, Pritzker signed House Bill 2028, which passed both the Senate and House of Illinois unanimously. This bill doubles the compensation rate for families of police officers and firefighters killed in the line of duty from $10,000 to $20,000. On March 13, 2023, Pritzker signed the Paid Leave for All Workers Act, which requires employers to give employees at least an hour of paid leave for every 40 hours of work, up to 40 hours per year, which employees can use for any reason. It went into effect in 2024.
== Characterization == Dextran has many favorable properties that make it an ideal candidate for applications as a drug delivery system. As a natural polymer, dextran is biocompatible and biodegradable in the human body. Dextran can also be chemically modified to produce derivatives at a low cost, which can address a few of the undesirable characteristics including its low mechanical strength and uncontrollable hydration rate [4]. This natural glucose polymer has excellent water solubility and prolonged circulation in the blood as well.
==== Antarctic plate ==== Marion hotspot (25) 46°54′S 37°36′E, w= 0.5 az= 080° ±12° Crozet hotspot (52) 46°06′S 50°12′E, w= 0.8 az= 109° ±10° rate= 25 ±13 mm/yr Possibly related to the Karoo-Ferrar geologic province (183 Ma) Kerguelen hotspot (20) 49°36′S 69°00′E, w= 0.2 az= 050° ±30° rate= 3 ±1 mm/yr Related to the Kerguelen Plateau (130 Ma) Heard hotspot (53), possibly part of Kerguelen hotspot 53°06′S 73°30′E, w= 0.2 az= 030° ±20° Île Saint-Paul and Île Amsterdam could be part of the Kerguelen hotspot trail (St. Paul is possibly not another hotspot) Balleny hotspot (2) 67°36′S 164°48′E, w= 0.2 az= 325° ±7° Erebus hotspot (54) 77°30′S 167°12′E
Sources: en.wikipedia.org
In June 2016 the Tritiated Water Task Force released a report on the status of tritium in tritiated water at Fukushima Daiichi nuclear plant, as part of considering options for final disposal of the stored contaminated cooling water. This identified that the March 2016 holding of tritium on-site was 760 TBq (equivalent to 2.1 g of tritium or 14 mL of pure tritiated water) in a total of 860,000 m3 of stored water. This report also identified the reducing concentration of tritium in the water extracted from the buildings etc. for storage, seeing a factor of ten decrease over the five years considered (2011–2016), 3.3 MBq/L to 0.3 MBq/L (after correction for the 5% annual decay of tritium). According to a report by an expert panel considering the best approach to dealing with this issue, "Tritium could be separated theoretically, but there is no practical separation technology on an industrial scale. Accordingly, a controlled environmental release is said to be the best way to treat low-tritium-concentration water." After a public information campaign sponsored by the Japanese government, the gradual release into the sea of the tritiated water began on 24 August 2023 and is the first of four releases through March 2024. The entire process will take "decades" to complete. China reacted with protest. The IAEA has endorsed the plan. The water released is diluted to reduce the tritium concentration to less than 1500 Bq/L, far below the limit recommended in drinking water by the WHO.
Potassium-40 is especially important in potassium–argon (K–Ar) dating. Argon is a gas that does not ordinarily combine with other elements. So, when a mineral forms – whether from molten rock, or from substances dissolved in water – it will be initially argon-free, even if there is some argon in the liquid. However, if the mineral contains traces of potassium, then decay of the 40K isotope present will create fresh argon-40 that will remain locked up in the mineral. Since the rate at which this conversion occurs is known, it is possible to determine the elapsed time since the mineral formed by measuring the ratio of 40K and 40Ar atoms contained in it. The argon in Earth's atmosphere is 99.6% 40Ar, but the argon in the Sun – and presumably in the primordial material that condensed into the planets – is mostly 36Ar, with less than 15% of 38Ar. It follows that most of Earth's argon derives from potassium-40 that decayed into argon-40, which eventually escaped to the atmosphere.
=== By mouth === The basic appeal of hypoglycemic agents by mouth is that most people would prefer a pill or an oral liquid to an injection. However, insulin is a peptide hormone, which is digested in the stomach and gut and in order to be effective at controlling blood sugar, cannot be taken orally in its current form. The potential market for an oral form of insulin is assumed to be enormous, thus many laboratories have attempted to devise ways of moving enough intact insulin from the gut to the portal vein to have a measurable effect on blood sugar. A number of derivatization and formulation strategies are currently being pursued to in an attempt to develop an orally available insulin. Many of these approaches employ nanoparticle delivery systems and several are being tested in clinical trials.
A variety of agents are added to sequester (deactivate) metal ions that otherwise catalyze the oxidation of fats. Common sequestering agents are disodium EDTA, citric acid (and citrates), tartaric acid, and lecithin.
A defining characteristic of Wagyu beef is its abundant, finely distributed intramuscular fat, referred to in Japanese as sashi. Among the four Wagyu breeds, this high degree of marbling is especially characteristic of Japanese Black cattle, whose beef has been reported to contain more than 30% intramuscular fat. The degree of marbling is influenced by genetic, physiological, and feeding factors, although the mechanisms that enable Japanese Black cattle to produce such highly marbled beef are not yet fully understood. Pronounced marbling is also found in Mishima cattle. Mishima and Kuchinoshima cattle—the latter producing lean meat—are the two native Japanese cattle populations considered to have remained free from European genetic influence. The occurrence of pronounced marbling in Mishima cattle therefore suggests that at least some native Japanese cattle already possessed a genetic capacity for marbling before European crossbreeding was used to develop the modern Wagyu breeds. Among Japanese Black cattle, the Tajima strain is less prone to depositing subcutaneous and intermuscular fat but readily develops intramuscular marbling. The fat in Japanese Black beef contains a high proportion of monounsaturated fatty acids, particularly oleic acid. This composition gives the fat a relatively low melting point and soft consistency, contributing to the characteristic melt-in-the-mouth texture and rich juiciness of highly marbled Wagyu beef. Beef from Japanese Black cattle also develops a distinctive rich, sweet aroma during cooking, commonly called "Wagyu beef aroma".
Sources: en.wikipedia.org
The lyophilised solid is best kept cold, dry and dark, typically at minus twenty degrees Celsius. Moisture and repeated warming cycles are the main causes of degradation. Solutions prepared from the powder are less stable and are normally used quickly.
Reversed-phase liquid chromatography assesses purity, while mass spectrometry confirms molecular mass and detects sequence errors. Amino acid analysis and peptide mapping add structural detail. These techniques are complementary rather than interchangeable.
It is listed as a prohibited peptide hormone by the World Anti-Doping Agency. No medicines regulator has approved it for human use. Import and sale rules vary by country.
It is a synthetic cyclic heptapeptide and a non-selective melanocortin receptor agonist. Structurally it is modelled on alpha-melanocyte-stimulating hormone, a peptide that occurs naturally in the body.