Everything below concerns eumelanin. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-10-22. Where a claim depends on a specific study, the study is described rather than over-claimed.
Regulatory treatment varies by country. In the United States, melanotan-2 is not approved for any indication, and products marketed for human use fall outside the approved drug framework. Some other jurisdictions have placed it under prescription controls or listed it as a prohibited or restricted substance. Online listings frequently describe the material as a research chemical, a category that does not carry the same manufacturing and labelling requirements as approved medicines.
Solid peptide material is generally stable when kept cold and dry. Common practice is storage at -20 degrees Celsius or lower, with desiccant and protection from light. Repeated freeze-thaw cycles and exposure to moisture are associated with degradation, aggregation, or loss of material. Once dissolved, stability depends on solvent, concentration, and temperature, and solutions are usually treated as short-lived unless stability data support longer periods. Handling notes typically emphasise minimising time at ambient temperature.
Identity and purity are assessed with chromatographic and mass spectrometric techniques. Reversed-phase high-performance liquid chromatography separates the target peptide from related impurities and degradation products, and the resulting retention time is compared against a reference standard. Mass spectrometry, often coupled to liquid chromatography, confirms molecular mass. Amino acid analysis or peptide mapping can provide additional sequence-level confirmation when required. Results are only as reliable as the reference materials used alongside them.
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.
| Property | Value | Notes |
|---|---|---|
| Solid-state storage | -20 degrees Celsius or lower | Desiccated and protected from light |
| Solution stability | Short and method-dependent | Confirm by stability testing |
| Purity assessment | Reversed-phase HPLC | Reported as area percent |
| Identity confirmation | LC-MS or comparable method | Mass match against expected value |
| Common synonyms | MT-II; melanotan II | Informal and catalogue names |
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.
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.
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.
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.
Independent verification is central to quality control because the compound is not produced under pharmaceutical manufacturing standards. Third-party laboratories can measure purity, identity, residual solvents, and microbial contamination, though the scope of testing varies between services. Reported analyses of vendor samples have shown batch-to-batch variation in peptide content and the presence of truncated or oxidized species. How much of this variation reflects synthesis conditions versus storage and shipping is not well characterized. No harmonized reference standard exists for the material as sold.
Handling guidance for melanotan II follows general practice for small synthetic peptides rather than a product-specific monograph. Lyophilized powder is typically kept at minus twenty degrees Celsius or colder, protected from light and moisture, because warmth and humidity accelerate degradation. Once reconstituted, solutions are usually refrigerated and used within a short window, as hydrolysis and microbial growth both become concerns. Repeated freeze-thaw cycles are generally avoided. These conventions come from laboratory peptide chemistry and not from formal stability studies on this specific compound.
Receptor studies place melanotan-2 among non-selective melanocortin agonists, binding MC1R, MC3R, MC4R and MC5R rather than a single subtype. Activation of MC1R on cutaneous melanocytes raises tyrosinase activity and shifts pigment synthesis toward eumelanin, which is darker and more photostable than pheomelanin. Central receptors, particularly MC4R, are associated with appetite suppression and with reported effects on sexual function. Because subtype selectivity is low, the same molecule engages pigment, metabolic and vascular pathways at once, and this breadth is a common explanation offered for the range of adverse events described in user reports.
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.
=== Names === Hydromorphone is known in various countries around the world by the brand names Hydal, Dimorphone, Exalgo, Sophidone LP, Dilaudid, Hydrostat, Hydromorfan, Hydromorphan, Hymorphan, Laudicon, Opidol, Palladone, Hydromorph Contin, and others. An extended-release version of hydromorphone, called Palladone, was available for a short time in the United States before being voluntarily withdrawn from the market after a July 2005 FDA advisory warned of a high overdose potential when taken with alcohol. As of March 2010, it is still available in Nepal under the brand name Opidol, in the United Kingdom under the brand name Palladone SR, and in most other European countries. There has also been a once-daily prolonged release version of hydromorphone available in Australia under the brand name Jurnista as of May 2009.
3-Allylfentanyl is an opioid analgesic that is an analogue of fentanyl. 3-Allylfentanyl has effects similar to fentanyl, although it is only 0.13x-0.14x as potent by weight. The decreased potency of this analogue caused by the addition of the allyl group makes it somewhat less dangerous than fentanyl itself (ED50(rat) of 80μg/kg vs 11μg/kg for fentanyl), although this is relative. For comparison, carfentanil is at least 20-30x as potent as fentanyl.
=== Weight loss industry === There is a substantial market for products which claim to make weight loss easier, quicker, cheaper, more reliable, or less painful. These include books, DVDs, CDs, cremes, lotions, pills, rings and earrings, body wraps, body belts and other materials, fitness centers, clinics, personal coaches, weight loss groups, and food products and supplements. Dietary supplements, though widely used, are not considered a healthy option for weight loss, and have no clinical evidence of efficacy. Herbal products have not been shown to be effective. In 2008, between US$33 billion and $55 billion was spent annually in the US on weight-loss products and services, including medical procedures and pharmaceuticals, with weight-loss centers taking between 6 and 12 percent of total annual expenditure. Over $1.6 billion per year was spent on weight-loss supplements. About 70 percent of Americans' dieting attempts are of a self-help nature. In Western Europe, sales of weight-loss products, excluding prescription medications, topped €1,25 billion (£900 million/$1.4 billion) in 2009. The scientific soundness of commercial diets by commercial weight management organizations varies widely, being previously non-evidence-based, so there is only limited evidence supporting their use, because of high attrition rates. Commercial diets result in modest weight loss in the long term, with similar results regardless of the brand, and similarly to non-commercial diets and standard care.
=== Entomopathic fungi === Entomopathic fungi have been used since 1965 for agricultural use. Hundreds of strains are now in use. They often kill a broad range of insect species. Most strains are from Beauveria, Metarhizium, Cordyceps and Akanthomyces species.
== History == After the leader of the Republican Liberal Party (PRL), António Granjo, was assassinated in the "Bloody Night" of 19 October 1921, the Liberals and Reconstituents started negotiations to merge the two parties in 1922. On 7 February 1923, the public manifesto of the Nationalist Republican Party was finally signed. The party constituted a "bloc of the Rights", intended to incorporate both conservative republicans and frustrated monarchists. It was designed to challenge the power of then hegemonic Democratic Party. The adherents of PRN were predominantly proprietors, shopkeepers, militaries, public servants, physicians, and lawyers. It held close links with the Banco Nacional Ultramarino and other important banks and major corporations. On 15 November 1923, the Nationalists formed a government, led by António Ginestal Machado. It included Óscar Carmona, future president of the Estado Novo, as minister of war and lasted one month. In December 1923, Álvaro de Castro left the PRN to form a new government, which did not include Nationalists, but Democrats, independents and members of the "Seara Nova". De Castro's government, which lasted until July 1924, was opposed by the PRN, most outspokenly by Francisco Cunha Leal. Notable leaders of the Nationalist Republican Party, besides Machado, included Tomé de Barros Queirós, Júlio Dantas, and José Mendes Cabeçadas, Cunha Leal, who left to found the Liberal Republican Union in 1926, and, after 1925, Commander Filomeno da Câmara de Melo Cabral, one of the organisers of the 18 April 1925 Generals' Coup.
Sources: en.wikipedia.org
=== Availability === GGC synthesis for commercial use is exceedingly difficult and, until recently, no commercially viable process for large scale production had been developed. The major drawback preventing the commercial success of chemical synthesis of GGC is the number of steps involved due to the three reactive groups on L-glutamic acid and L-cysteine molecules, which must be masked to achieve the correct regioisomer. Similarly, there have been numerous attempts at biological production of GGC by fermentation over the years and none have been successfully commercialised. Towards the end of 2019, a biocatalytic process was successfully commercialized. GGC is now available as a supplement in the US under the trademarked name of Glyteine and Continual-G.
Calcium gluconate is the calcium salt of gluconic acid and is used as a mineral supplement and medication. As a medication it is used by injection into a vein to treat low blood calcium, high blood potassium, and magnesium toxicity. Supplementation is generally only required when there is not enough calcium in the diet. Supplementation may be done to treat or prevent osteoporosis or rickets. It can also be taken by mouth but is not recommended for injection into a muscle. Side effects when injected include slow heart rate, pain at the site of injection, and low blood pressure. When taken by mouth side effects may include constipation and nausea. Blood calcium levels should be measured when used and extra care should be taken in those with a history of kidney stones. At normal doses, use is regarded as safe in pregnancy and breastfeeding. Calcium gluconate is made by mixing gluconic acid with calcium carbonate or calcium hydroxide. Calcium gluconate came into medical use in the 1920s. It is on the World Health Organization's List of Essential Medicines. Calcium gluconate is available as a generic medication. It is closely related to calcium borogluconate, which is commonly used in veterinary medicine owing to its higher solubility. It is used for intravenous administration of calcium, notably in ruminants.
In patients with non-severe asymptomatic aortic valve stenosis, increased age- and sex adjusted N-terminal pro-brain natriuretic peptide (NT-proBNP) levels alone and combined with a 50% or greater increase from baseline had been found associated with increased event rates of aortic valve stenosis related events (cardiovascular death, hospitalization with heart failure due to progression of aortic valve stenosis, or aortic valve replacement surgery). In patients with non-severe asymptomatic aortic valve stenosis and no overt coronary artery disease, the increased troponin T (above 14 pg/mL) was found associated with an increased 5-year event rate of ischemic cardiac events (myocardial infarction, percutaneous coronary intervention, or coronary artery bypass surgery).
== Preparation == Divinyl sulfone is prepared from the diacetate bis(2-hydroxyethyl)sulfide. Oxidation of this diester with hydrogen peroxide gives the sulfone. The sulfone is then pyrolyzed to induce elimination of two equivalents of acetic acid:
=== Deep brain stimulation === Earlier practitioners of deep brain stimulation in the latter half of the 20th century (Delgado, Heath, Hosbuchi. See Hariz et al. for historical review) were limited by the technology available. Heath, in the 1950s, stimulated subcortical areas and made detailed observations of behavioral changes. In the 1950s, Professor Heath reported on subcortical stimulation with precise descriptions of behavioral changes. A new understanding of pain perception was ushered in in 1965, with the Gate Theory of Wall and Melzack, allowing the beginning a gradual move away from destructive surgical treatments such as cutting nerves and towards reversible, modulatory treatments: neuromodulation. Although now considered oversimplified, the theory held that pain transmissions from small nerve fibers can be overridden, or the gate "closed", by competing transmissions along the wider touch nerve fibers. Building on that concept, in 1967, the first dorsal column stimulator for pain control was demonstrated by Dr. Norm Shealy at Western Reserve Medical School, using a design adapted by Tom Mortimer, a graduate student at Case Institute of Technology, from cardiac nerve stimulators by Medtronic, Inc., where he had a professional acquaintance who shared the circuit diagram. In 1973, Hosbuchi reported alleviating the denervation facial pain of anesthesia dolorosa through ongoing electrical stimulation of the somatosensory thalamus, marking the start of the age of deep brain stimulation.
Sources: en.wikipedia.org
Laboratory confirmation typically combines retention time matching on a chromatographic system with mass measurement. A reference standard of known identity is needed for a meaningful comparison. Sequence-level techniques can add further confirmation.
There is no single harmonised standard governing these products, and manufacturing conditions differ. Impurities may include truncated sequences, oxidation products, residual solvents, and counter-ions. Independent testing is often the only way to characterise a given lot.
Reported studies have looked at pigmentation, photoprotection, and metabolic or appetite-related endpoints in small experimental settings. Much of the evidence base is early-stage and limited in size. Questions about long-term effects and clinical relevance remain open.
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.