alpha-MSH analogue comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-03-23. 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.
The peptide was developed during the 1980s by researchers investigating melanocortin signalling and skin pigmentation pathways. Early work focused on analogues of alpha-melanocyte-stimulating hormone that would resist enzymatic breakdown more effectively than the parent molecule. Melanotan-2 emerged from that programme as a shortened, cyclised variant. Reports describing its synthesis and receptor activity later appeared in the scientific literature. Commercial availability grew through unregulated channels rather than through pharmaceutical approval.
Structurally, Melanotan-2 retains the core recognition motif of alpha-melanocyte-stimulating hormone while adding a lactam bridge that links two side chains and constrains the molecule into a ring. This modification lowers susceptibility to enzymatic degradation. The compound acts as an agonist at melanocortin receptors, particularly subtypes associated with melanin production. Because the same receptor family influences several physiological processes, researchers note that its activity is not confined to pigmentation alone. Receptor selectivity continues to be examined in published studies.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its sequence incorporates modified residues that increase potency and extend biological activity relative to the native hormone. The compound binds receptors of the melanocortin family and is examined mainly in laboratory research. It does not occur naturally and exists only as a manufactured chemical entity produced by solid-phase synthesis.
| 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 |
No regulatory authority has approved melanotan-2 for human use, and several countries classify it as a prescription-only or controlled substance, which restricts lawful supply. Material sold online is generally labelled as a research chemical and is not required to meet pharmaceutical standards of identity or purity. Published human data consist mainly of small uncontrolled studies, case reports and adverse-event notifications, so the evidence base is descriptive rather than confirmatory. Whether repeated melanocyte stimulation alters long-term naevus behaviour remains an open question that no completed trial has resolved.
Melanotan-2 is a synthetic cyclic heptapeptide designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous tridecapeptide that regulates pigment production. Two modifications distinguish it from the natural hormone: norleucine replaces methionine at the N-terminus, which limits oxidation, and a D-phenylalanine substitution raises receptor affinity. The ring is closed through an aspartate-lysine lactam bridge, giving the molecule a constrained conformation. The free base has a molecular mass near 1024 daltons, and commercial material is usually supplied as an acetate salt. It appears in the literature as a research peptide rather than an approved therapeutic agent.
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.
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.
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.
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.
=== As food === Journalist Alistair Cooke claimed that rattlesnake tastes "just like chicken, only tougher". Others have compared the flavor to a wide range of other meats, including veal, frog, tortoise, quail, fish, rabbit, and even canned tuna. Methods of preparation include barbecueing and frying; author Maud Newton, following a recipe by Harry Crews, described the taste, "at least when breaded and fried, like a sinewy, half-starved tilapia."
Abbreviation recognition – identify the long-form and abbreviation of biological terms Named-entity recognition – recognizing biological terms such as gene names Protein–protein interaction – identify which proteins interact with which proteins from text The area of research draws from statistics and computational linguistics.
While the Rockefeller doctors working in tropical locales such as Mexico emphasized scientific neutrality, they had political and economic aims to promote the value of public health to improve American relations with the host country. Although they claimed the banner of public health and humanitarian medicine, they often engaged with politics and business interests. Rhoads was involved in a racism whitewashing scandal in the 1930s during which he joked about injecting cancer cells into Puerto Rican patients, inspiring Puerto Rican nationalist and anti-colonialist leader Pedro Albizu Campos. Noguchi was also involved in an unethical human experimentation scandal. Susan Lederer, Elizabeth Fee, and Jay Katz are among the modern scholars who have researched this period. Researchers with the foundation including Noguchi developed the vaccine to prevent yellow fever. Rhoads later became a significant cancer researcher and director of Memorial Sloan-Kettering, though his eponymous award for oncological excellence was renamed after the scandal reemerged.
Hookah, Sasuba and Snuba systems are categorised as "air-line" equipment, as they do not include the communication, lifeline and pneumofathometer hose characteristic of a full diver's umbilical. Most hookah diving uses a demand system based on a standard scuba second stage, but there have been special purpose free-flow full-face masks specifically intended for hookah diving (see photos). A bailout system, or emergency gas supply (EGS) is not an inherent part of an air-line diving system, though it may be required in some applications. Their field of application is very different from full surface-supplied diving. Hookah is generally used for shallow water work in low-hazard applications, such as archaeology, aquaculture, and aquarium maintenance work, but is also sometimes used for open water hunting and gathering of seafood, shallow water mining of gold and diamonds in rivers and streams, and bottom cleaning and other underwater maintenance of boats. Sasuba and Snuba are mainly a shallow water recreational application for low-hazard sites. Sasuba and hookah diving equipment is also used for boat maintenance and hull cleaning, swimming pool maintenance, and shallow underwater inspections. The systems used to supply air through the hose to a demand valve mouthpiece, are either 12-volt electrical air pumps, gasoline engine powered low-pressure compressors, or floating scuba cylinders with high pressure regulators. These hookah diving systems usually limit the hose length to allow less than 7 metres depth.
Sources: en.wikipedia.org
Charcot–Marie–Tooth disease was first discovered in 1886 by three scientists: Jean-Martin Charcot (1825–1893) and his assistant Pierre Marie (1853–1940), along with the English doctor Howard Henry Tooth (1856–1925). In their original publication, titled “Concerning a Special Form of Progressive Muscular Atrophy,” Charcot and Marie acknowledged that similar cases had been previously published in medical literature. Their findings described hereditary neuropathy, marked by gradual muscle wasting and diminished sensation in the extremities. This crucial discovery helped establish CMT as a distinct clinical entity, differentiating it from other neuromuscular conditions such as muscular dystrophies. Over the years, advancements in neurogenetics have led to the identification of various genetic mutations responsible for the disease, significantly enhancing our understanding of its pathogenesis and classification. Charcot also noted that prior descriptions of the disease were neither objective nor thorough. Most of the earlier accounts merely mentioned that CMT was hereditary. As a result, Charcot felt it was essential to provide a comprehensive description of the disease, ensuring that it received the attention it deserved. In 2010, Charcot–Marie–Tooth (CMT) disease became one of the first conditions in which the precise genetic cause was identified in an individual patient using whole-genome sequencing. This groundbreaking discovery was made by scientists affiliated with the Charcot–Marie–Tooth Association (CMTA).
Legio I I Armeniaca I Flavia Constantia (reliable Flavian): comitatensis unit under the command of the Magister militum per Orientis I Flavia Gallicana Constantia (reliable Flavian legion from Gallia): pseudocomitatensis under the command of the Magister Peditum per Gallias. The legion was founded by Constantius I Chlorus. The legions objective was to protect the Armorican coast and fight the Roman-British usurper, Allectus. I Flavia Martis (Flavian legion devoted to Mars): pseudocomitatensis. The legion was founded by Constantius Chlorus to fight Allectus. It was stationed in Gaul. I Flavia Pacis (Flavian legion of peace): comitatensis under the command of the Magister Peditum I Flavia Theodosiana: comitatensis. I Illyricorum (of the Illyrians): stationed at the Camp of Diocletian in Palmyra I Iovia (devoted to Jupiter): levied by Diocletian, stationed at Noviodunum in Scythia Minor I Isaura Sagittaria (archers from Isauria): pseudocomitatensis under the command of the Magister militum per Orientis I Iulia Alpina: pseudocomitatensis under the command of the Magister Peditum in Italy. It is unknown who founded the legion although it was probably Crispus or Constans. I Martia possibly based near modern Kaiseraugst. The Legion could have had the surname Victrix. The legion was probably founded by Diocletian. It also may have built forts in Valeria. I Maximiana Thaebanorum (the Thebans of Maximianus): comitatensis unit stationed near Thebes, Egypt, and probably fighting in the battle of Adrianople I Noricorum (of the Noricans): stationed in Noricum.
Age-Related Changes in Expression and Activity of Human Hepatic Mitochondrial Glutathione Transferase Zeta1. Zhong G, James MO, Smeltz MG, Jahn SC, Langaee T, Simpson P, Stacpoole PW. Drug Metab Dispos. 2018 Aug;46(8):1118-1128. doi: 10.1124/dmd.118.081810. Epub 2018 May 31. PMID: 29853471 Free PMC article. Glutathione transferase zeta1 (GSTZ1) catalyzes glutathione (GSH)-dependent dechlorination of dichloroacetate (DCA), an investigational drug with therapeutic potential in metabolic disorders and cancer. ...In samples from livers with the GSTZ1C variant, apparent enzyme kin … Phase 1 trial of dichloroacetate (DCA) in adults with recurrent malignant brain tumors. Dunbar EM, Coats BS, Shroads AL, Langaee T, Lew A, Forder JR, Shuster JJ, Wagner DA, Stacpoole PW. Invest New Drugs. 2014 Jun;32(3):452-64. doi: 10.1007/s10637-013-0047-4. Epub 2013 Dec 3. PMID: 24297161 Free PMC article. Clinical Trial. All subjects completing at least 1 four week cycle remained clinically stable during this time and remained on DCA for an average of 75.5 days (range 26-312). CONCLUSIONS: Chronic, oral DCA is feasible and well-tolerated in patients with recurrent malignant gliomas …
== Further reading == Pohlschroder, Mechthild; Pfeiffer, Friedhelm; Schulze, Stefan; Halim, Mohd Farid Abdul (1 September 2018). "Archaeal cell surface biogenesis". FEMS Microbiology Reviews. 42 (5): 694–717. doi:10.1093/femsre/fuy027. PMC 6098224. PMID 29912330.
== Use and effects == In his book PiHKAL (Phenethylamines I Have Known and Loved), Alexander Shulgin lists TMA-2's dose as 20 to 40 mg orally and its duration as 8 to 12 hours. In earlier publications, it was described that threshold effects occur at a dose of 10 mg orally, an effective dose is 16 to 20 mg orally, its onset of psychoactive effects is after 1 hour, and a plateau of effects occurs from 3 to 6 hours following administration. The drug is much more potent than its positional isomer 3,4,5-trimethoxyamphetamine (3,4,5-TMA, TMA, or TMA-1), which is said to be active at doses of 100 to 250 mg orally and to have a duration of 6 to 8 hours. However, DOM (2,5-dimethoxy-4-methylamphetamine), the analogue of TMA-2 in which its 4-methoxy group has been replaced with a more lipophilic 4-methyl group, is about 10 times more potent than TMA-2. TMA-2 has been said to have a sharp dose–response curve, with several additional toxic symptoms occurring at doses of 25 to 30 mg. The effects of TMA-2 have been reported to include color and contrast enhancement, closed-eye imagery like kaleidoscopic images, visuals such as visual distortion and movement, auditory enhancement, increased salience of objects in one's environment, cosmic thinking, time dilation, and music and erotic enhancement.
Sources: en.wikipedia.org
== Complications == The denaturing of proteins by an aqueous solution containing many types of ions is more complicated as all the ions can act, according to their Hofmeister activity, i.e., a fractional number specifying the position of the ion in the series (given previously) in terms of its relative efficiency in denaturing a reference protein. At high salt concentrations lysozyme protein aggregation obeys the Hofmeister series originally observed by Hofmeister in the 1870s, but at low salt concentrations electrostatic interactions rather than ion dispersion forces affect protein stability resulting in the series being reversed. However, at high concentrations of salt, the solubility of the proteins drops sharply and proteins can precipitate out. Ion binding to carboxylic surface groups of macromolecules can either follow the Hofmeister series or the reversed Hofmeister series depending on the pH. The concept of Hofmeister ionicity Ih has been invoked by Dharma-wardana et al. where it is proposed to define Ih as a sum over all ionic species, of the product of the ionic concentration (mole fraction) and a fractional number specifying the "Hofmeister strength" of the ion in denaturing a given reference protein. The concept of ionicity (as a measure of the Hofmeister strength) used here has to be distinguished from ionic strength as used in electrochemistry, and also from its use in the theory of solid semiconductors.
Climate change and energy policy played a role in the 2024 presidential campaign. In 2023, the United States saw a record in crude oil production with over 13.2 million barrels of crude per day, beating the 13 million barrels per day produced at the peak of Trump's presidency. The United States also dealt with supply shocks caused by the 2021–2024 global energy crisis due to the COVID-19 pandemic and Russian invasion of Ukraine. An advocate for environmental justice to address the impact of climate change on lower-income areas and people of color, Harris supported Biden's climate legislation. In 2022, Harris helped pass the Inflation Reduction Act, the largest investment in addressing climate change and clean energy in American history, putting the United States on track to meet emissions reduction targets by 50–52% below 2005 levels by 2030. Harris's campaign stated that she would not support a ban on fracking. Trump ridiculed the idea of man-made climate change, and repeatedly referred to his energy policy under the mantra "drill, baby, drill". Trump said he would increase oil drilling on public lands and offer tax breaks to oil, gas, and coal producers, and stated his goal for the United States to have the lowest cost of electricity and energy of any country in the world. Trump also promised to roll back electric vehicle initiatives, proposed once again the United States withdrawal from the Paris Agreement, and rescind several environmental regulations. Trump stated his intention to roll back parts of the Inflation Reduction Act, Biden's signature domestic legislation.
=== 1981: reconstitution === In March 1981, the Minister for the Arts and Minister for Educational Services, Norman Lacy, had the Victorian College of the Arts Act passed through the Victorian Parliament. Its purpose was the reconstitution of the Victorian College of the Arts (VCA) made necessary by the repeal in 1980 of the Victorian Institute of Colleges Act and to make it "better able to provide for the preparation of young people to enter upon careers as professional artists. It also represented a significant development for the Victorian Arts Centre." Lacy laid out a rationale for the re-constitution of the college under a VCA specific act which was derived firstly "from the quite specific demands and circumstances of preparing young artists for professional practise." He asserted that "the basic concept upon which the college is built is that young artists intending to enter careers as practitioners in their various fields are best assisted to achieve their ambitions in a milieu of continuous artistic activity and endeavour of a fully professional nature. To the extent that artistic education is separated from normal professional practice it is so much less effective." Secondly, the rationale related to the adjacent location of the VCA campus to the National Gallery of Victoria and the Victorian Arts Centre. He said that this "Greater Arts Centre concept is central to the government's decision to reconstitute the college by separate statute as well as to the development of the arts in general.
Fire (火) = Heart (心; xīn) and Small Intestine (小腸; xiaǒcháng) (and, secondarily, Sānjiaō [三焦, "Triple Burner"] and Pericardium [心包; xīnbaò]) Earth (土) = Spleen (脾; pí) and Stomach (胃; weì) Metal (金) = Lung (肺; feì) and Large Intestine (大腸; dàcháng) Water (水) = Kidney (腎; shèn) and Bladder (膀胱; pángguāng) Wood (木) = Liver (肝; gān) and Gallbladder (膽; dān) The zàng-fǔ are also connected to the twelve standard meridians – each yang meridian is attached to a fǔ organ, and five of the yin meridians are attached to a zàng. As there are only five zàng but six yin meridians, the sixth is assigned to the Pericardium, a peculiar entity almost similar to the Heart zàng.
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.
It is a synthetic cyclic heptapeptide and an analogue of alpha-melanocyte-stimulating hormone. The molecule is produced by chemical synthesis rather than extracted from a biological source.