The short version of afamelanotide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-11-04 and is reviewed periodically as new material appears.
Pharmacologically, melanotan-2 behaves as a non-selective agonist across the melanocortin receptor family. Binding at MC1R on dermal melanocytes promotes eumelanin synthesis, which underlies the tanning response described in early human work. Activity at the centrally expressed MC4R receptor is associated with reported effects on appetite and erectile function. Because the peptide does not discriminate strongly among receptor subtypes, attributing any single observed effect to one receptor pathway is generally not possible without selective antagonists or receptor knockout models.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | Melanotan II; MT-II; N-acetyl-norleucyl-cyclo[Asp-His-D-Phe-Arg-Trp-Lys] amide | Naming follows peptide convention; the numeral distinguishes it from melanotan-1 |
| Molecular formula | C50H69N15O9 | Includes the lactam bridge; no counter-ion assumed |
| Monoisotopic mass | 1023.53 Da | Free base; salts and counter-ions shift the observed value |
| Appearance | White to off-white lyophilised powder | Batch-to-batch colour variation is not itself proof of impurity |
| Typical analytical method | RP-HPLC purity determination with ESI-MS identity confirmation | Retention time alone does not establish sequence identity |
== Background == This was the first of the new President Trump's executive orders and was a mass undoing of the previous president's policies on a wide range of issues. Its core effect was the rescinding of several executive orders ordered by President Biden. It was followed that day by 25 other executive orders covering a wide range of policies and was signed in an open to the public event with attendance by Vice President JD Vance.
History of cancer Unexplained weight loss Immunosuppression Urinary infection Intravenous drug use Prolonged use of corticosteroids Back pain not improved with conservative management History of significant trauma Minor fall or heavy lift in a potentially osteoporotic or elderly individual Acute onset of urinary retention, overflow incontinence, loss of anal sphincter tone, or fecal incontinence Saddle anesthesia Global or progressive motor weakness in the lower limbs Being over the age of 50 or under the age of 25
== O == Ohira–Bestmann reaction Olah reagent Olefin metathesis Oppenauer oxidation Orton rearrangement Ostromyslenskii reaction, Ostromisslenskii reaction Overman rearrangement Oxidative decarboxylation Oxo synthesis Oxy-Cope rearrangement Oxymercuration Oxidation of alcohols to carbonyl compounds Ozonolysis
=== Immunity === The main immune cells active in the tissue are macrophages and neutrophils, although other leukocytes are also present. These work to phagocytize old or damaged tissue, and protect the healing tissue from pathogenic infection. This is necessary both to aid the healing process and to protect against invading pathogens, as the wound often does not have an effective skin barrier to act as a first line of defense.
The nephritic syndrome is characterised by blood in the urine (especially Red blood cell casts with dysmorphic red blood cells) and a decrease in the amount of urine in the presence of hypertension. In this syndrome, inflammatory damage to cells lining the glomerulus are thought to result in destruction of the epithelial barrier, leading to blood being found in the urine. At the same time, reactive changes, e.g. proliferation of mesangial cells, may result in a decrease in kidney blood flow, resulting in a decrease in the production of urine. The renin–angiotensin system may be subsequently activated, because of the decrease in perfusion of juxtaglomerular apparatus, which may result in hypertension.
Sources: en.wikipedia.org
244Cm(13C,xn)257−xNo (x=4) This reaction was first studied in 1957 at the Nobel Institute in Stockholm. The scientists detected 8.5 MeV alpha particles with a half-life of 10 minutes. The activity was assigned to 251No or 253No. The results were later dismissed as background. The reaction was repeated by scientists at the LBNL in 1958 but they were unable to confirm the 8.5 MeV alpha particles. The reaction was further studied in 1967 at the LBNL and an activity assigned to 253No was measured.
== Description == Eupolyphaga sinensis is often described as a wingless cockroach, this however is not entirely true. E. sinensis is a sexually dimorphic species, with the females being wingless, while the males are winged. Females are generally larger in size and darker in color than males. Within their range E. sinensis display significant size differences based on temperature and latitude. Body size of both males and females increase at high and low latitudes, with those found at an intermediate range being smaller. This body size difference is a result of genetic differentiation between populations, being adapted to their native climate.
=== The mathematics of substitution models === Stationary, neutral, independent, finite sites models (assuming a constant rate of evolution) have two parameters, π, an equilibrium vector of base (or character) frequencies and a rate matrix, Q, which describes the rate at which bases of one type change into bases of another type; element
=== Effect on French colonies === The Viet Minh victory in the war had an inspirational effect to independence movements in various French colonies worldwide, most notably the FLN in Algeria. The Algerian War broke out on 1 November 1954, only six months after the Geneva Conference. Benyoucef Benkhedda, later became the head of the Provisional Government of the Algerian Republic, praised the Viet Minh feat at Dien Bien Phu as "a powerful incentive to all who thought immediate insurrection the only possible strategy". The French Communist Party played an even stronger role by supplying the National Liberation Front (FLN) rebels with intelligence documents and financial aid. They were called "the suitcase carriers" (les porteurs de valises). In the French news, the Indochina War was presented as a direct continuation of the Korean War, where France had fought: a UN French battalion, incorporated in a U.S. unit in Korea, was later involved in the Battle of Mang Yang Pass of June and July 1954. In an interview taped in May 2004, General Marcel Bigeard (6th BPC) argues that "one of the deepest mistakes done by the French during the war was the propaganda telling you are fighting for Freedom, you are fighting against Communism", hence the sacrifice of volunteers during the climactic battle of Dien Bien Phu. In the latest days of the siege, 652 non-paratrooper soldiers from all army corps from cavalry to infantry to artillery dropped for the first and last time of their life to support their comrades.
Sources: en.wikipedia.org
and this results in a small population bias favoring the lower energy state in thermal equilibrium. With more spins pointing up than down, a net spin magnetization along the magnetic field B0 results.
==== Angiotensin II receptor blockers (ARBs) ==== Angiotensin II receptor blockers (ARBs) work by inhibiting the action of angiotensin II on, specifically AT1 receptors to prevent the vasoconstrictor effects of this receptor and block the peripheral sympathetic activity.
He claimed that Mubadala attempted to take over all shares of the founders, and “intentionally delayed” transferring units to them. Getir's founders also stated that Mubadala attempted to back off from the deal at the end of 2024. They appealed to the Enterprise Chamber of the Amsterdam Court of Appeal, and said to take a legal action in Turkey and the UK as well. Mubadala was planning to propose an alternative plan, which it said was already approved by Getir's independent directors. But Salur expressed his intent to “continue fighting” the restructuring plan. On 30 January 2025, Salur removed Getir's CEO Batuhan Gultakan from his position without giving specific reasons. Sources revealed that the move was taken due to Gultakan's full support towards Mubadala. In December 2024, Mubadala announced a partnership with Silver Rock Financial LP in which Mubadala Capital acquired a 42% stake in the company. Mubadala Capital acquired the Canadian asset manager CI Financial Corp. in August 2025 for $8.9 billion. Also in August 2025, Mubadala invested $35 million for a 12.8% stake into Paragraf, a British technology company. Mubadala Capital acquired the outdoor advertising company Clear Channel Outdoor in February 2026 for $6.2 billion.
=== Biofilm formation === The ability to adhere to medical devices and subsequently form biofilms is a major virulence factor associated with S. haemolyticus. Biofilm formation increases antibiotic resistance and often leads to persistent infections. S. haemolyticus biofilms are not polysaccharide intercellular adhesin (PIA) dependent, and the lack of the ica operon (the gene cluster that encodes the production of PIA) can be used to distinguish S. haemolyticus isolates from other CoNS species. Biofilm formation is influenced by a variety of factors including carbohydrates, proteins, and extracellular DNA. Detachment assays with NaIO4, proteinase K, or DNase result in 38%, 98%, and 100% detachment, respectively. The high level of detachment associated with DNase treatment has led several authors to suggest a cell-to-surface and/or cell-to-cell adhesion function for extracellular DNA. Biofilm formation also appears to be influenced by the presence of glucose and NaCl. Biofilm formation is enhanced when cultivated in TSB with 1% glucose and decreased when cultivated in TSB with 3% NaCl. The production of a capsular polysaccharide decreases biofilm formation. Subinhibitory concentrations (subminimum inhibitory concentrations) of the antibiotic dicloxacillin also affect the growth of S. haemolyticus biofilms. Biofilms formed in the presence of subinhibitory concentrations of dicloxacillin contain less biomass and have an altered composition. They are thinner, cover less surface area, and are less hydrophobic, but they also have an increased level of resistance to dicloxacillin.
=== Religious use === Mescaline-containing cacti are used as entheogens for religious purposes by certain Latin American and Native American and groups. The Huichol (Wixárika) people of Mexico and the Native American Church use peyote, while the native people of Peru use the San Pedro cactus (huachuma). The use of mescaline-containing cacti for such purposes by Mexican and South American people dates back thousands of years. The use of peyote spread from the Huichol people into Native American tribes such as the Kiowa and Comanche in the late 1800s.
Sources: en.wikipedia.org
It is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, containing seven amino acids with a lactam ring and a D-configured phenylalanine residue. It is supplied as a lyophilised powder for laboratory research.
The natural hormone is a linear tridecapeptide that is rapidly degraded in circulation. Melanotan-2 is shortened, cyclised, N-terminally acetylated, and carries a D-amino acid substitution, all of which slow enzymatic breakdown.
No national medicines regulator has approved melanotan-2 for therapeutic or cosmetic use. In several jurisdictions it is treated as an unapproved prescription medicine, and its legal classification differs from country to country.
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.