A practical reference on alpha-MSH: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-06-14 and is reviewed periodically as new material appears.
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.
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controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports.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.
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.
Two structural changes distinguish the synthetic peptide from the natural hormone. A norleucine residue replaces methionine at one position, and a D-configured phenylalanine replaces the natural L-form at another. Both substitutions slow enzymatic breakdown, which extends the molecule's persistence relative to the parent hormone. The lactam bridge further constrains the backbone into a stable conformation. These features are standard design strategies in peptide chemistry and are not unique to this compound; they appear across many research peptides built for improved stability.
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.
== Properties == Vitamers often have subtly different properties from their primary, or most common form. These differences include abundance in the typical diet, bioavailability, toxicity, physiological activities, and metabolism. Some vitamers are associated with different benefits for health compared to other forms of the same vitamin. Folic acid, a vitamer of vitamin B9 commonly added to fortified foods and dietary supplements, is 0.7–1.0 times more bioavailable than vitamers of vitamin B9 found in minimally processed foods. Differences in digestion and absorption account for the notable differences in bioavailability between vitamers of vitamin B9. Forms of vitamin B9 that occur in minimally processed foods, sometimes referred to as "food folates", require digestion by enzymatic hydrolysis prior to absorption whereas folic acid does not. Some vitamins have toxic effects when consumed in excess amounts and certain vitamers have a greater potential for toxicity compared to other forms of the same vitamin. For example, hypervitaminosis A is a toxicity syndrome caused by excess consumption of retinoid vitamers of vitamin A such as retinol, retinal, and retinoic acid. In contrast, provitamin A carotenoids such as beta-carotene are not associated with these toxic effects. Nicotinic acid and nicotinamide are two vitamers of vitamin B3 that exhibit differences in metabolism. Large, pharmaceutical doses of the nicotinic acid are used under medical supervision as a treatment for hypercholesterolemia.
Well-being has traditionally focused on improving physical, emotional and mental quality of life with little understanding of how dependent they all are on financial health. However, financial stress often manifests itself in physical and emotional difficulties that lead to increased healthcare costs and reduced productivity. A more inclusive paradigm for well-being would acknowledge money as a source of empowerment that maximizes physical and emotional health by reducing financial stress. Such a model would provide individuals with the financial knowledge they need, as well as enable them to gain valuable insight and understanding regarding their financial habits, as well as their thoughts, feelings, fears and attitudes about money. Through this work, individuals would be better equipped to manage their money and achieve the financial wellness that is essential for their overall well-being. It has been argued that money cannot effectively "buy" much happiness unless it is used in certain ways, and that "Beyond the point at which people have enough to comfortably feed, clothe, and house themselves, having more money – even a lot more money – makes them only a little bit happier." In his book Stumbling on Happiness, psychologist Daniel Gilbert described research suggesting money makes a significant difference to the poor (where basic needs are not yet met), but has a greatly diminished effect once one reaches middle class (i.e. the Easterlin paradox).
Down welling light intensity allows the bobtail squid to hide from predators by mimicking moonlight and starlight intensity as it hunts for prey at night. There is also development of blue crab defense, which utilizes sensory organs for detecting chemical changes in the water to alert them of predators. When alerted blue crabs will hide as a defensive strategy. The urine from predators acts as a selective pressure so that blue crabs which are more sensitive to chemical change are likely to survive. Those that survive increase the likelihood that offspring develop the same sensory organs for detection. However, there is a distinctive difference between development of the sensory organs, ability to process or accumulate toxins or bacteria compared to leaned or habit developing defensive strategy.
This method incorporated a parallelized, adapter/ligation-mediated, bead-based sequencing technology and served as the first commercially available "next-generation" sequencing method, though no DNA sequencers were sold to independent laboratories.
Sources: en.wikipedia.org
Recreational use of psychedelics has been common since the psychedelic era of the mid-1960s and continues to feature at festivals and events such as Burning Man. A 2013 survey found that 13.4% of American adults had used a psychedelic at some point in their lives. A June 2024 report by the RAND Corporation indicated that psilocybin mushrooms are currently the most widely used psychedelic drug among U.S. adults. According to the RAND national survey, 3.1% of adults reported psilocybin use in the past year, while about 12% reported lifetime use. Similar lifetime prevalence was reported for LSD, whereas MDMA (ecstasy) showed lower lifetime use at 7.6%. Fewer than 1% of adults reported using any psychedelic in the past month. A nationwide survey of 11,299 adults in Germany, published in 2025, found that 5.0% of respondents reported lifetime psychedelic use, with 0.7% reporting use within the past six months. Approximately 3% of respondents had used LSD, LSD analogues, psilocybin, or related substances at least once in their lifetime, and 0.5% had done so within the past six months. Lifetime prevalence of medium-to-high dosing (3.9%) was higher than microdosing (2.7%). Usage patterns varied by sociodemographic characteristics, including sex, age, residence, income, and marital status.
== Other consequences == Dean Robinson, who was sacked by the club in February 2013 when it self-reported the program, brought an unfair dismissal case against the club, which was settled in October 2014 for a $1 million payout. Most of the club's expenses related to the scandal, including legal bills and the payout to Robinson, were covered by Essendon's insurers, Chubb Limited. Hird, however, was left with a large personal legal bill, because the insurance policy for administrative staff covered only the defence of a legal action, not initiating a legal action against others. Hird unsuccessfully sued Chubb for approximately $660,000 in costs in his 2014 court challenges of legality of the AFL/ASADA joint investigation, but it was later revealed that a benefactor who was not publicly identified stepped in to cover the costs. Hird's total legal costs from the saga, including covering ASADA's costs in his failed cases against it, totalled $1.74 million. Former player Hal Hunter, who was on the rookie list during the program but was not among the thirty-four players suspended, sued the club to obtain full documentation about what substances he was administered at the club. After a year-long legal battle, the Supreme Court ruled in early 2016 that Essendon had already provided Hunter with all documentation it had; Hunter was initially ordered to cover Essendon's legal costs for the lawsuit, but that was reversed after mediation. Similarly to the other 34 players, Hunter received a compensation package from Essendon for involving him in the program.
=== Oncology === Theranostics has been applied in oncology, contributing to new approaches in the diagnosis, treatment, and monitoring of cancers. By integrating diagnostic imaging and targeted therapies, theranostics offers personalized approaches that improve treatment outcomes and patient care. In oncology, theranostics encompasses a wide range of applications, including the management of various types of cancers such as breast, lung, prostate, and colorectal cancer. Molecular imaging techniques, such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT), enable the visualization and characterization of cancerous lesions, aiding in early detection, staging, and assessment of treatment response. This allows for more accurate and tailored treatment planning, including the selection of appropriate targeted therapies or the optimization of radiation therapy. Despite the significant progress, the translation of theranostics into routine clinical practice faces challenges, including the need for standardized imaging protocols, biomarker validation, and regulatory considerations. Additionally, there is a continuous need for research and development to further enhance the effectiveness and accessibility of theranostic approaches in oncology.
== Reactivity == Ninhydrin exists in equilibrium with the triketone indane-1,2,3-trione, which reacts readily with nucleophiles (including water). Whereas for most carbonyl compounds, a carbonyl form is more stable than a product of water addition (hydrate), ninhydrin forms a stable hydrate of the central carbon because of the destabilizing effect of the adjacent carbonyl groups. To generate the ninhydrin chromophore [2-(1,3-dioxoindan-2-yl)iminoindane-1,3-dione], the amine must condense to give a Schiff base. The reaction of ninhydrin with secondary amines gives an iminium salt, which is also coloured, generally being yellow–orange.
Research has focused on changing the mixture of keratins produced in the skin. There are 54 known keratin genes—of which 28 belong to the type I intermediate filament genes and 26 to type II—which work as heterodimers. Many of these genes share substantial structural and functional similarity, but they are specialized to cell type and/or conditions under which they are normally produced. If the balance of production could be shifted away from the mutated, dysfunctional keratin gene toward an intact keratin gene, symptoms could be reduced. For example, sulforaphane, a compound found in broccoli sprouts and few other vegetables, was found to reduce blistering in a mouse model to the point where affected pups could not be identified visually, when injected into pregnant mice (5 μmol/day = 0.9 mg) and applied topically to newborns (1 μmol/day = 0.2 mg in jojoba oil). As of 2008, clinical research at the University of Minnesota has explored allogeneic bone marrow transplantation for RD and junctional EB, treating a two-year-old child who is one of two brothers with EB. A second transplant has also been performed on the child's older brother. A Missouri boy has also successfully undergone the transplant, as well as a 5 year old boy from Alabama. So far there have been 12 successful transplants. Another transplant is scheduled for a California baby. A clinical trial is planned for 30 subjects. However, the immune suppression that bone marrow transplantation requires causes a risk of serious infections with large scale blisters and skin erosion.
Sources: en.wikipedia.org
== History == The use of iboga in African spiritual ceremonies was first reported by French and Belgian explorers in the 19th century, beginning with the work of French naval physician and explorer of Gabon Marie-Théophile Griffon du Bellay. The first botanical description of the Tabernanthe iboga plant was made in 1889. Ibogaine was first isolated from T. iboga in 1901 by Dybowski and Landrin and independently by Haller and Heckel in the same year using T. iboga samples from Gabon. Complete synthesis of ibogaine was accomplished by G. Büchi in 1966. Since then, several other synthesis methods have been developed. Use of low doses of ibogaine (e.g. 10–30 mg/day) as a stimulant and "anti-fatigue" drug in the treatment of conditions like "cardiac atony", neurasthenia, and convalescence was advocated by French researchers in 1905. From the 1930s to 1960s, ibogaine was sold in France as Lambarène, an extract of the Tabernanthe manii plant, and promoted as a mental and physical stimulant. It was formulated at doses of 200 mg extract containing low doses of 4 to 8 mg ibogaine per tablet. The drug enjoyed some popularity among post-World War II athletes. Lambarène was withdrawn from the market in 1966 when the sale of ibogaine-containing products became illegal in France. Another formulation was Iperton, which contained Tabernanthe iboga extract 40 mg per dose unit. In 2008, Mačiulaitis and colleagues stated that in the late 1960s, the World Health Assembly classified ibogaine as a "substance likely to cause dependency or endanger human health". The U.S.
==== Educational institutions ==== The law changes the excise tax on the investment income of tax-exempt educational institutions. There are three different excise tax rates, and the highest excess tax rate is 8 percent. The excise tax rate depends on the institution's ratio of its investment assets to its eligible students. Institutions with higher ratios are subject to higher excise tax rates.
=== Journalist spying scandal === In October 2022, Forbes reported that a team at ByteDance planned to surveil certain US citizens for undisclosed reasons. TikTok said that the tracking method suggested by the report would not be feasible because precise GPS information is not collected by the platform. In December 2022, ByteDance confirmed after internal investigation that the data of two journalists and their close contacts had been accessed by its employees from China and the United States. It was intended to uncover sources of leaks who might have met with the journalists from Forbes and the Financial Times. The data included IP addresses, which can be used to approximate a user's location. ByteDance stated that it fired four employees in response. The incident is being investigated by the US Department of Justice and FBI. The US Attorney for the Eastern District of Virginia reportedly subpoenaed information from ByteDance regarding its surveillance of journalists on TikTok. In December 2023, the United States House Select Committee on Strategic Competition between the United States and the Chinese Communist Party inquired the FBI about the status of the case.
=== Pathophysiology === In critical illness, the activity of different deiodinases is altered. Humoral and neuronal inputs at the level of the hypothalamus may adjust the set point of thyroid homeostasis. This may play an important role in the pathogenesis of the central component of thyroid allostasis in critical illness, tumors, uremia and starvation (TACITUS). In addition, both illness and medication (e.g. salicylates and heparin) may impair plasma protein binding of thyroid hormones, resulting in reduced levels of total hormones, while free hormone concentrations may be temporarily elevated. Euthyroid sick syndrome probably represents an overlap of an allostatic response with pathologic reactions and drug interferences. Allostatic overload may result in wasting syndrome and myxedema coma. Thyroid storm, though, represents allostatic failure, where the organism is unable to develop NTIS in the situation of thyrotoxicosis.
On May 20, 2025, U.S. president Donald Trump announced plans for a new space-based missile defense system called the "Golden Dome" intended to shield the United States from long-range and hypersonic missiles. The name alludes to Israel's Iron Dome but the system is planned to be orders of magnitude broader in scope. Technical details and deployment plans were not released. Trump said the project would be completed within three years and cost about $175 billion, a feasibility, timeline, and price estimate that were quickly and widely disputed. The Congressional Budget Office estimated that it could cost between $161 billion and $542 billion over 20 years, while Republican senators involved in the program predicted it would ultimately cost "trillions of dollars." In April 2025 the Director, Operational Test and Evaluation (DOT&E) determined that the Golden Dome fell under its oversight, as they are required by law to analyze testing plans for defense programs with procurements above $3 billion. Days later, Elon Musk's Department of Government Efficiency (DOGE) investigated the office and slashed its resources. A defense official told CNN that they believed DOGE wanted to prevent DOT&E conducting independent oversight of the Golden Dome. In May 2025, 42 members of US Congress formally asked the DoD Inspector General to review Elon Musk’s involvement in the Golden Dome.
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.