eumelanin raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-11-27. Anything still debated is marked as such rather than presented as settled.
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.
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 |
|---|---|---|
| Molecular formula | C50H69N15O9 | Cyclic heptapeptide, C-terminally amidated |
| Approximate molecular mass | 1024 Da | Monoisotopic mass of the free peptide |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility class | Soluble in water and polar solvents | Also dissolves in neutral aqueous buffer |
| Common synonyms | Melanotan II, MT-II, MT-2 | Described as a melanocortin agonist in early literature |
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.
Research interest has centred on photoprotection and pigmentation, with a smaller body of work on appetite and sexual function. Published human data remain limited to small, frequently uncontrolled studies, and the compound has never received marketing approval from a national medicines regulator. Most laboratory work treats it as a pharmacological tool for probing melanocortin signalling in cell culture or animal models. Whether pigmentation changes observed in people translate into measurable protection against ultraviolet-induced DNA damage remains an open question.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, the naturally occurring peptide involved in pigmentation signalling. Its sequence is conventionally written as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, with a lactam bridge joining the aspartate side chain to the lysine side chain. The empirical formula is C50H69N15O9 and the monoisotopic mass lies near 1023.5 daltons. N-terminal acetylation and the D-configured phenylalanine both increase resistance to enzymatic breakdown compared with the parent hormone.
=== Mental disorders === Vaccines do not cause autism. There have been no successful attempts to reproduce fraudulent research by British ex-doctor Andrew Wakefield, where the misconception likely originates. Wakefield's research was ultimately shown to have been manipulated. Dyslexia is not defined or diagnosed as mirror writing or reading letters or words backwards. Mirror writing and reading letters or words backwards are behaviors seen in many children (dyslexic or not) as they learn to read and write. Dyslexia is a neurodevelopmental disorder of people who have at least average intelligence and who have difficulty in reading and writing that is not otherwise explained by low intelligence. Self-harm is not generally an attention-seeking behavior. People who engage in self-harm are typically very self-conscious of their wounds and scars and feel guilty about their behavior, leading them to go to great lengths to conceal it from others. They may offer alternative explanations for their injuries, or conceal their scars with clothing. There is no evidence that a chemical imbalance or neurotransmitter deficiency is the sole factor in depression and other mental disorders, but rather a combination of biological, psychological, and social factors. Schizophrenia does not involve split or multiple personalities. It is characterized by continuous or relapsing episodes of psychosis. Major symptoms include hallucinations (typically hearing voices), delusions, paranoia, and disorganized thinking. Other symptoms include social withdrawal, decreased emotional expression, and apathy.
The minerals, results of biomineralization processes regulated by the environment or bacteria, are also essential components of the exopolysaccharides. They provide structural integrity to biofilm matrix and act as a scaffold to protect bacterial cells from shear forces and antimicrobial chemicals. The minerals in EPS were found to contribute to morphogenesis of bacteria and the structural integrity of the matrix. For example, in Bacillus subtilis, Mycobacterium smegmatis, and Pseudomonas aeruginosa biofilms, calcite (CaCO3) contributes to the integrity of the matrix. The minerals also associate with medical conditions. In the biofilms of Proteus mirabilis, Proteus vulgaris, and Providencia rettgeri, the minerals calcium and magnesium cause catheter encrustation.
On 22 July 2018, the PSL nominated Bolsonaro for president in the 2018 election. The Brazilian Labour Renewal Party also endorsed him. His coalition name was "Brazil above everything, God above everyone" (Brasil acima de tudo, Deus acima de todos). Though contested by two lawsuits, the Superior Electoral Court of Brazil deferred them and his candidacy was made official on 6 August. In August Bolsonaro announced that Antônio Hamilton Mourão, a retired army general, would be his running mate.
Adrenal crisis, also known as Addisonian crisis or acute adrenal insufficiency, is a life-threatening complication of adrenal insufficiency. Hypotension and hypovolemic shock are the main symptoms of an adrenal crisis. Other symptoms include weakness, anorexia, nausea, vomiting, fever, fatigue, abnormal electrolytes, confusion, and coma. Laboratory testing may detect low sodium, high potassium, high lymphocyte count, high eosinophils, low blood sugar, and rarely high calcium. The biggest trigger for adrenal crisis is gastrointestinal illness. Those with primary adrenal insufficiency are at a higher risk for an adrenal crisis. The physiological mechanisms underlying an adrenal crisis involve the loss of endogenous glucocorticoids' typical inhibitory effect on inflammatory cytokines. When someone with adrenal insufficiency exhibits symptoms of an adrenal crisis, treatment must begin immediately. To diagnose an adrenal crisis, serum cortisol, aldosterone, ACTH, renin, and dehydroepiandrosterone sulfate are measured. A low cortisol level of less than 3 mg/dL, measured in the early morning or during a stressful period, suggests a diagnosis of adrenal insufficiency. A tailored prescription, and strategies for administering additional glucocorticoids for physiological stress, are critical preventative measures. When someone experiences an adrenal crisis, they require immediate parenteral hydrocortisone. About 6–8% of those with adrenal insufficiency experience an adrenal crisis at some point each year. The mortality rate linked to adrenal crises is up to 6%.
According to Annex 13 of the Convention on International Civil Aviation, an aviation accident is an occurrence associated with the operation of an aircraft, which takes place from the time any person boards the aircraft with the intention of flight until all such persons have disembarked, and in which (a) a person is fatally or seriously injured, (b) the aircraft sustains significant damage or structural failure, or (c) the aircraft goes missing or becomes completely inaccessible. Annex 13 defines an aviation incident as an occurrence, other than an accident, associated with the operation of an aircraft that affects or could affect the safety of operation. A hull loss occurs if an aircraft is damaged beyond repair, is lost, or becomes completely inaccessible.
Sources: en.wikipedia.org
== Adverse effects == There is a need for controlled clinical trials before the safety of ibogaine can be established; existing evidence, largely from uncontrolled case reports, links it to significant acute and long-term adverse events (especially cardiac issues like QTc prolongation), including fatalities. It should only be used in medically supervised settings with thorough screening and continuous cardiac and psychiatric monitoring. Ibogaine can cause various cardiovascular changes (e.g., slowed heart rate, blood pressure shifts), neurological effects (ataxia, tremor, mania), and rare but serious complications, including arrhythmias, respiratory failure, and death, especially when combined with opioids or in patients with underlying conditions. Cardiac risks likely occur through hERG channel blockade leading to QT prolongation and arrhythmias; the synthetic analog 18-MC appears to produce much less of this dangerous effect despite similar binding affinity. A 2022 review found 58 ibogaine-associated emergencies, including 38 deaths. Two of these deaths occurred in the setting of clinical studies. According to a 2012 estimate, 1 in every 300 patients who take ibogaine die.
NBOMe-LAD, also known as LSD-NBOMe, is a serotonin receptor modulator and putative psychedelic drug of the lysergamide family related to lysergic acid diethylamide (LSD). It is the N-(2-methoxybenzyl) (NBOMe) derivative of LSD.
Fostemsavir (an HIV attachment inhibitor) and lenacapavir (an HIV capsid inhibitor) are indicated in heavily treatment-experienced adults with multidrug-resistant HIV-1 infection failing their current antiretroviral regimen due to resistance, intolerance, or safety considerations. Melarsoprol — a highly toxic antiprotozoal typically reserved for use only in late stages of the T. b. rhodesiense type of African trypanosomiasis, wherein it remains the only treatment; often results in polyneuropathy and reactive encephalopathy, resulting in death in around 5% of patients. Linezolid — used to treat drug-resistant infections of the skin and pneumonia; use is limited due to high cost and risk of vision loss or myopathy. Tigecycline — used to kill Acinetobacter and Legionella species; limited by high cost, risk of liver injury and an apparent increase in mortality.
=== Anime === An anime television series adaptation of the first part was announced on April 10, 2025. It is produced by Wit Studio and directed by Ken Yamamoto, with Kazuhiro Furuhashi serving as animation adviser, Ayumu Hisao handling series composition, Namiko Torii designing the characters, and Kensuke Ushio composing the music. The series aired from March 29 to June 28, 2026 on Tokyo MX and other networks, with an advance screening held on March 15 of the same year at Shinjuku Wald 9 in Tokyo. The opening theme song is "Petals" (ペタルズ, Petaruzu), while the ending theme song is "Hana Ikada" (花筏), both performed by Orangestar featuring Kase. Crunchyroll is streaming the series in simulcast with an English dub. Muse Communication licensed the series in Southeast Asia.
Sources: en.wikipedia.org
Outrageous. It exacerbates inequality and social division—one of the main problems of the USA. It deprives vulnerable groups of access to health care. Life expectancy is already declining, and the health differences between rich and poor are enormous. This law exacerbates this. The nonpartisan Tax Foundation had mixed opinions of the bill, saying it made "some smart cuts", in particular praising the extension of the Tax Cuts and Jobs Act of 2017 which it argued would provide stability for households. It also expressed support for its impacts on counting international business income. It criticized the political nature of the bill, calling it filled with carve-outs and political gimmicks that increased the complexity of the tax code. It also criticized the bill's non-equal application of taxation on citizens. The Economist described the bill's policies and passage as an example of "America's creeping dysfunction", criticizing its impact on increasing the deficit and describing its tax cuts as "gimmicks". It also criticized Trump's handling of the economy more broadly, saying the bill "illustrates the long-term damage Mr Trump is doing to the foundations of America's economy" and describing its passage as exacerbating the effects of Trump's attacks on the Federal Reserve, defunding of scientific research, high tariff policy, and erosion to the rule of law. It described these cumulative effects as threatening America's economic stability and making it a riskier place to invest.
Though there is no strict rule on what to consume and what not to, the food habits of Hindus vary according to their specific caste and sub-caste, community, location, custom and varying traditions. Historically and currently, a majority of Hindus (about 70%) eat meat, while a large proportion of Hindus are vegetarian (about 30%). Some sects of Hinduism such as Vaishnavism follow the purest form of vegetarianism as an ideal while Shaktism and Tantric sects freely consume chicken, mutton (goat and sheep meat), fish and eggs. The reasons stated by Jains and Vaishnavas are: the principle of nonviolence (ahimsa) applied to animals; the intention to offer only "pure" (vegetarian) food to a deity and then to receive it back as prasada; and the conviction that a sattvic diet is beneficial for a healthy body. A sattvic diet is lacto-vegetarian, which includes dairy, but excludes eggs. An overwhelming majority of the Hindus consider the cow to be a holy and sacred animal whose slaughter for meat is forbidden. Thus, beef is a taboo for the majority of Hindus, Jains and Sikhs
== Description == Leaves are aromatic, simple and lanceolate, obovate-elliptic or elliptic, size of 5–15 cm × 2–5 cm, coriaceous to thickly coriaceous. The leaves are 5–15 cm × 1.5–5 cm, apex acute, lower side pubescent. Flowers are solitary, bisexual, pink to dark red, axillary or subterminal. The perianth has 7–12 lobes, arranged spirally; 11–20 stamens, arranged spirally, with short, thick filaments; and usually 8 carpels, free, arranged in a single whorl. Flower peduncle size is 1.5–4 cm, tepals number range from seven to twelve, and are broadly elliptic to broadly ovate, anthers size is 1–1.5 mm, pollen grains trisyncolpate. The fruit is a capsule-like follicetum, star-shaped, reddish-brown, consisting of six to eight follicles arranged in a whorl. Each follicle is boat-shaped, 1–2 cm long, rough and rigid, color reddish-brown, with 1 seed, opening along the ventral edge when ripe. carpels size of 10 mm long, boat-shaped; they are hard and wrinkled, containing one seed. Seeds are brown, compressed ovoid, smooth, shiny and brittle with approximate size of 8–9 mm × 6 mm. Differences with similar taxa: Illicium anisatum had smaller fruits that does not form a regular star due to the abortion of some carpels. Also fruit follicles are not swollen in the middle and had a more pointed apex. Also usually had more than 8 follicles and the fruit has weaker odour. The seeds in Illicium anisatum are flat or almost spherical.
In 2007, a new natural peptide was discovered in the human organism and was called VIRIP. It is generated from alpha-1-antitrypsin, a protease inhibitor that belongs to the serine family, by matrix metalloproteinases. It was shown that it could interact with the HIV-1 and stop the virus multiplication. In spite of interacting in a highly intensity with gp-41, the VIRIP did not prevent the multiplication of the virus. So, it was decided to increase the efficacy of this molecule creating other ones that could be more powerful. Among these 600 created molecules, there was the VIR-576 which was synthesized using the solid-phase peptide synthesis method. Moreover, another molecule was used to protect the amino groups, the fluorenylmethyloxycarbonyl chloride. The next step was the purification before lyophilizing it with mannitol. Other peptides were made such as the VIR-353 or the VIR-449.
The major cell-matrix adhesion receptors are integrins and therefore the adhesome of cell-matrix adhesion is referred to as the integrin adhesome. Cell-cell adhesion is primarily mediated by cadherin receptors and therefore the adhesome of cell-cell adhesion is referred to as the cadherin adhesome or cadhesome. The first attempts to establish the set of proteins that participate directly ('bona fide' adhesome components) or affect indirectly ('associated' adhesome components) cell adhesion were based on mining of the primary research literature, and resulted in approximately 200 protein in either integrin or cadherin adhesomes. Later, unbiased proteomic approaches utilizing mass spectrometry have detected hundreds more proteins associated with integrin adhesions. However, a comparison of multiple proteomic studies of the integrin adhesome of fibroblasts attached to fibronectin found only 60 proteins common to all studies. Humphries and co-workers named these 60 proteins the 'consensus integrin adhesome'.
Sources: en.wikipedia.org
No. It is a synthetic analogue carrying four amino acid changes, a lactam ring and an amidated C-terminus. The natural hormone is a linear thirteen-amino-acid peptide processed from proopiomelanocortin.
Afamelanotide is the linear analogue [Nle4-D-Phe7]-alpha-MSH, sometimes called melanotan I, while melanotan II is cyclic and carries three further substitutions. The two are distinct molecules and are not interchangeable in analytical testing.
Binding to the four melanocortin receptor subtypes is well documented in vitro. The relative contribution of each subtype to whole-body effects in humans is far less certain.
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.