Everything below concerns melanocortin receptor. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-02-16. Numbers and descriptions here follow the published literature rather than marketing material.
Published human data come mostly from small, short studies rather than large controlled trials. Reported outcomes include increased skin pigmentation and, in some reports, effects on appetite and libido, but sample sizes are small and follow-up is limited. Whether long-term use produces durable pigment changes or adverse effects is not established. Because products sold outside pharmacies are not standardized, the actual content of any given vial is often unknown. Independent testing of such material is uncommon.
Melanotan II is a synthetic cyclic heptapeptide analog derived from the core sequence of alpha-melanocyte-stimulating hormone. Researchers at the University of Arizona synthesized it during the 1980s while studying pigmentation and appetite signaling. The compound is not an approved medicine in any major jurisdiction and appears mainly in laboratory and research-chemical settings. Its structure incorporates a lactam bridge between side chains, which constrains the ring and slows enzymatic breakdown relative to the natural hormone.
Melanotan II binds several melanocortin receptor subtypes rather than a single target. MC1R on melanocytes drives melanin synthesis, while MC3R and MC4R participate in energy balance, appetite, and sexual response pathways. This lack of selectivity explains why reported effects extend beyond skin darkening. Substitutions at positions four and seven, including norleucine and D-phenylalanine, increase potency and resistance to peptidases. Understanding which receptor mediates which effect remains an active area of investigation.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Analog of alpha-melanocyte-stimulating hormone |
| Primary receptor family | Melanocortin receptors MC1R through MC5R | Binding is not subtype-selective |
| Development period | 1980s | Synthesized during pigmentation and appetite research |
| Regulatory status | Not an approved medicine | No major regulator has authorized human use |
| Related compound | Afamelanotide | Linear analog studied for photoprotection |
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.
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.
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.
Little People of the World Organization Archived 2021-05-10 at the Wayback Machine [Hub for all International Organizations; services/advocacy/know your rights/support] Little People of America (Includes a list of International support groups) Little People of Canada (Includes a list of Canadian Provincial support groups) Little People UK Dwarf Sports Association UK Restricted Growth Association UK
an optimized medium (for Chlamydomonas reinhardtii), an examination of the nutritional conditions including higher salinity and nitrogen concentration (for Botryococcus braunii), the addition of sulfate and magnesium salts in the culture medium (P. cruentum), a co-culturing of Chlorella and Spirulina with the Basidiomycete Trametes versicolor, and a novel mutagenesis tool (atmospheric and room temperature plasma, ARTP), leading to an increase of EPS production of up to 34% (volumetric yield of 1.02 g/L). It was suggested that co-cultures of microalgae and other microorganisms can be used more universally as a technology to increase the production of EPS, since microorganisms may respond to the interaction partners by secreting EPS as a strategy during unfavorable conditions.
== Treatment == Although the origin of the disease is unknown, there is speculation that it is an aggressive healing response to small tears in the plantar fascia, almost as if the fascia over-repairs itself following an injury. There is also some evidence that it might be genetic. In the early stages, when the nodule is single and/or smaller, it is recommended to avoid direct pressure to the nodule(s). Soft inner soles on footwear and padding may be helpful. MRI and sonogram (diagnostic ultrasound) are effective in showing the extent of the lesion, but cannot reveal the tissue composition. Even then, recognition of the imaging characteristics of plantar fibromatoses can help in the clinical diagnosis. Surgery of Ledderhose's disease is difficult because tendons, nerves, and muscles are located very closely to each other. Additionally, feet have to carry heavy load, and surgery might have unpleasant side effects. If surgery is performed, the biopsy is predominantly cellular and frequently misdiagnosed as fibrosarcoma. Since the diseased area (lesion) is not encapsulated, clinical margins are difficult to define. As such, portions of the diseased tissue may be left in the foot after surgery. Inadequate excision is the leading cause of recurrence. Radiotherapy has been shown to reduce the size of the nodules and reduce the pain associated with them. It is approximately 80% effective, with minimal side effects. Post-surgical radiation treatment may decrease recurrence. There has also been variable success in preventing recurrence by administering gadolinium.
Due to its extremely long half-life, 209Bi can be treated as non-radioactive for nearly all applications. It is much less radioactive than human flesh, so it poses no real radiation hazard. Though 209Bi holds the half-life record for alpha decay, it does not have the longest known half-life of any nuclide; this distinction belongs to tellurium-128 (128Te) with a half-life estimated at 7.7×1024 years by double beta decay. The half-life of 209Bi was confirmed in 2012 by an Italian team in Gran Sasso who reported (2.01±0.08)×1019 years. They also reported an even longer partial half-life for alpha decay of 209Bi to the first excited state of 205Tl (at 204 keV), estimated at 1.66×1021 years. Even though this value is shorter than the half-life of 128Te, both alpha decays of 209Bi hold the record of the thinnest natural line widths of any measurable physical excitation, estimated respectively at ΔΕ ≈ 5.5×10−43 eV and ΔΕ ≈ 1.3×10−44 eV in application of the uncertainty principle
=== Polyendocrine metabolic ovarian syndrome === In those with polyendocrine metabolic ovarian syndrome (PMOS), tentative evidence shows that metformin use increases the rate of live births. This includes those who have not been able to get pregnant with clomiphene. Metformin does not appear to change the risk of miscarriage. A number of other benefits have also been found both during pregnancy and in nonpregnant people with PMOS. In an updated Cochrane review on metformin versus placebo/no treatment before or during IVF/ICSI in women with PMOS, no conclusive evidence of improved live birth rates was found. In long GnRH-agonist protocols there was uncertainty in the evidence of improved live birth rates but there could be increases in clinical pregnancy rate. In short GnRH-antagonist protocols metformin may reduce live birth rates with uncertainty on its effect on clinical pregnancy rate. Metformin may result in a reduction of OHSS but could come with a greater frequency of side effects. There was uncertainty as to metformin's impact on miscarriage. The evidence does not support general use during pregnancy for improving maternal and infant outcomes in obese women. The United Kingdom's National Institute for Health and Clinical Excellence recommended in 2004 that people with PMOS and a body mass index above 25 be given metformin for anovulation and infertility when other therapies fail to produce results.
Sources: en.wikipedia.org
1973 ) tax lawyer, investigative journalist and commentator, researches and writes on issues of tax law and tax policy; worked as tax lawyer at international law firm Clifford Chance, becoming its UK head of tax ; was listed as one of the 50 most influential people in the world of tax policy and business by International Tax Review, and as one of the 100 most influential people in the world of private wealth by Spear's; was named the UK's leading accountancy influencer on social media by the Institute of Chartered Accountants in England and Wales; served on the National Constitutional Committee of the Labour Party, its senior disciplinary body; advises policymakers in five political parties and was member of the Scottish Government's Tax Advisory Group. Robert Peston (born 1960), BBC news business correspondent; author of Who Runs Britain? How the Super-Rich are Changing our Lives; son of Maurice Peston, Baron Peston (1931–2016), an economist and Labour life peer who had worked on the Lords Constitution Committee and on committee reviewing the BBC Charter and was chairman of the Pools Panel.
== Medical use == Evidence for benefit of PRP is mixed, with some evidence for use in certain conditions and against use in other conditions. It has been investigated for chronic tendinitis, osteoarthritis, in oral surgery, and in plastic surgery.
Aflatoxins – originating from Aspergillus parasiticus and Aspergillus flavus. They are frequently found in tree nuts, peanuts, maize, sorghum and other oilseeds, including corn and cottonseeds. The pronounced forms of aflatoxins are those of B1, B2, G1, and G2, amongst which Aflatoxin B1 predominantly targets the liver, which will result in necrosis, cirrhosis, and carcinoma. Other forms of aflatoxins exist as metabolites such as Aflatoxin M1. In the US, the acceptable level of total aflatoxins in foods is less than 20 μg/kg, except for Aflatoxin M1 in milk, which should be less than 0.5 μg/kg. The European union has more stringent standards, set at 10 μg/kg in cereals and cereal products. These references are also adopted in other countries. Altertoxins – are those of alternariol (AOH), alternariol methyl ether (AME), altenuene (ALT), altertoxin-1 (ATX-1), tenuazonic acid (TeA), and radicinin (RAD), originating from Alternaria spp. Some of the toxins can be present in sorghum, ragi, wheat and tomatoes. Some research has shown that the toxins can be easily cross-contaminated between grain commodities, suggesting that manufacturing and storage of grain commodities is a critical practice. Citrinin Citreoviridin Cyclopiazonic acid Cytochalasins Ergot alkaloids / ergopeptine alkaloids – ergotamine Fumonisins – Crop corn can be easily contaminated by the fungi Fusarium moniliforme, and its fumonisin B1 will cause leukoencephalomalacia (LEM) in horses, pulmonary edema syndrome (PES) in pigs, liver cancer in rats and esophageal cancer in humans.
=== Health and accident === On the evening of August 3, 2008, Freeman was injured in an automobile crash when his 1997 Nissan Maxima was involved in a rollover near Ruleville, Mississippi. He and his passenger, Demaris Meyer, had to be cut free from the vehicle with hydraulic tools. Freeman was conscious after the crash and joked with a photographer at the scene. He was taken via helicopter to The Regional Medical Center (The Med) hospital in Memphis. His left shoulder, arm, and elbow had been broken, and he received surgery on August 5. Doctors operated on him for four hours to repair nerve damage in his shoulder and arm. His publicist announced he was expected to make a full recovery. Although alcohol was not considered a factor in the crash, Meyer sued Freeman for negligence, claiming that he had been consuming alcohol, but the suit was eventually settled for an undisclosed amount. Freeman developed fibromyalgia following the incident, and had to switch dominant hands as his left was paralyzed. In 2010, he was diagnosed with stage 1 colon cancer and underwent a successful surgery to remove the tumor.
Sources: en.wikipedia.org
=== Acquired and inherited enzyme deficiencies === Downregulation of kynurenine 3-monooxygenase (KMO) can be caused by genetic polymorphisms, cytokines, or both. KMO deficiency leads to an accumulation of kynurenine and to a shift within the tryptophan metabolic pathway towards kynurenic acid and anthranilic acid. Deficiencies of one or more enzymes on the kynurenine pathway leads to an accumulation of intermediate metabolic products which can cause effects depending on their concentration, function and their inter-relation with other metabolic products. For example, kynurenine 3-monooxygenase deficiency is associated with disorders of the brain (such as schizophrenia and tic disorders) and of the liver. The mechanism behind this observation is typically a blockade or bottleneck situation at one or more enzymes on the kynurenine pathway due to the effects of indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) and/or due to genetic polymorphisms afflicting the particular genes. Dysfunctional states of distinct steps of the kynurenine pathway (such as kynurenine, kynurenic acid, quinolinic acid, anthranilic acid, 3-hydroxykynurenine) have been described for a number of disorders, for example:
The World Bank reports that, in 2007, electricity was largely supplied by local businesses. Among these domestic firms is the Somali Energy Company, which performs generation, transmission and distribution of electric power. In 2010, the nation produced 310 million kWh and consumed 288.3 million kWh of electricity, ranked 170th and 177th, respectively, according to the CIA.
Churchill is a man with an out-of-date political idea—that of the European balance of power. It no longer belongs to the sphere of realities. And yet it's because of this superstition that Churchill stirred England up to war. On another occasion he added: Without the Wehrmacht, a "wave would have swept over Europe that would have taken no care of the ridiculous British idea of the balance of power in Europe in all its banality and stupid tradition—once and for all." In fact, Churchill shortly adopted a similar view: Our Russian friends and Allies, he spoke in 1946, most admire strength and least respect military weakness. "For that reason the old doctrine of a balance of power is unsound. We cannot afford … to work on narrow margins, offering temptations to a trial of strength." If the Western Democracies do not stand together "then indeed catastrophe may overwhelm us all." If, however, "the population of the English-speaking Commonwealths be added to that of the United States with all that such co-operation implies in the air, on the sea, all over the globe and in science and in industry, and in moral force, there will be no quivering, precarious balance of power to offer its temptation to ambition or adventure. On the contrary, there will be an overwhelming assurance of security."
Sources: en.wikipedia.org
No regulator in a major market has approved it for human use. It appears in research settings and in products marketed outside pharmacy channels. Legal status for personal possession varies by country.
Afamelanotide is a linear analog that has received approval in some jurisdictions for a specific photoprotection indication. Melanotan II is cyclic and less selective across melanocortin receptors. The two are related but are not interchangeable in regulatory or clinical terms.
A compound that activates several receptor subtypes may produce effects beyond pigmentation. Selectivity influences which tissues respond and shapes the side-effect profile described in reports. Designing subtype-selective analogs is a stated goal of melanocortin research.
No regulatory agency has authorised melanotan-2 as a medicine for any indication. It circulates mainly as a research chemical or through unregulated channels. As a result, identity, purity and content are not independently guaranteed.