Everything below concerns salt form. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-03-22. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Identification in laboratories relies on reversed-phase liquid chromatography coupled with tandem mass spectrometry, with product-ion spectra compared against a certified reference standard. High-resolution mass spectrometry supplies accurate mass confirmation, and peptide mapping after enzymatic digestion separates melanotan II from closely related analogues. Quantitation of seized material is complicated by unknown counter-ions and residual trifluoroacetate left from purification. Immunoassays raised against alpha-melanocyte-stimulating hormone can cross-react, so chromatographic confirmation is normally required. Urinary detection windows are short, and reported limits of detection differ substantially between laboratories.
Melanotan II holds no marketing authorisation from the Food and Drug Administration, the European Medicines Agency, the UK Medicines and Healthcare products Regulatory Agency or Australia's Therapeutic Goods Administration. Products sold under that name are treated as unapproved new drugs, and their sale or import is prohibited in several jurisdictions. Other countries classify the peptide as a prescription-only medicine or place it among controlled substances, so the legal position changes with the destination market. No pharmacopoeial monograph supplies an official specification, because the material is not a licensed pharmaceutical. Consequently, products offered online are not manufactured to a shared public standard.
| 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 |
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.
Because the substance circulates mainly through informal markets, verification is a recurring theme in technical discussion. Independent analyses have found that labeled content and actual content can diverge, and that purity varies between samples. Analytical laboratories use reversed-phase chromatography to separate components and mass spectrometry to confirm identity. Isotope-labeled internal standards improve quantification in complex matrices. Such methods describe what a sample contains but say nothing about its sterility, lawful status, or suitability for any use. Open questions remain about how consistently testing is applied across the supply chain.
Regulatory treatment of this peptide varies by country. It holds no marketing authorization as a medicine in the United States, the European Union, or most other jurisdictions. Some countries classify products containing it as prescription-only or unlicensed medicines, which restricts lawful supply. Authorities have issued public notices warning that unregulated products may contain undeclared or incorrect ingredients. The molecule also appears on prohibited lists for competitive sport. These measures address supply oversight rather than any approved therapeutic role.
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.
Solid peptide kept dry at minus twenty degrees Celsius, shielded from light and moisture, is generally considered stable for extended periods. Solutions are divided into single-use aliquots and held at minus twenty or minus eighty degrees Celsius, because repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. Hydrolysis of the backbone and oxidation of tryptophan are the principal degradation routes in aqueous solution, and both accelerate at ambient temperature. Hygroscopic uptake after a vial is opened can also shift the actual mass weighed, which affects any concentration calculated from it.
Routine characterisation relies on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, using a C18 column and a water-acetonitrile gradient containing trifluoroacetic acid. Electrospray ionisation mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidised by-products that co-elute poorly. Sequence and stereochemistry require additional work, such as peptide mapping or amino acid analysis, because a chromatographic purity figure alone does not distinguish a diastereomer from the target peptide. Independent testing of research-grade material frequently shows measured content below the stated label, so a certificate of analysis is best read together with the method that produced it.
Melanotan-2 is handled in the laboratory as a lyophilised powder that dissolves readily in water, dimethyl sulfoxide and dimethylformamide, with limited solubility in ethanol. Stock solutions prepared in an organic solvent often precipitate when diluted into aqueous buffer, so gradual dilution with mixing is standard practice. The peptide carries a tryptophan residue and a histidine residue, both sensitive to oxidation and to alkaline conditions. Working solutions are therefore kept near neutral to slightly acidic pH, protected from light, and consumed within the same working session whenever that is practical.
Blood sugar levels are regulated by negative feedback in order to keep the body in balance. The levels of glucose in the blood are monitored by many tissues, but the cells in the pancreatic islets are among the most well understood and important. Granule docking is an important glucose-dependent step in human insulin secretion that does not work properly in type 2 diabetes.
After the excavation of the Arabia, the next challenge for the partners of River Salvage Inc. was learning to clean and preserve the artifacts. During the digging process, organic artifacts had been stabilized in blocks of ice, both in Jerry Mackey's restaurant freezers as well as freezers installed in storage units in caves near the Missouri River. In the three months following the dig, larger wooden artifacts, including the stern, paddle wheel, and the lumber for two prefabricated houses found on board, were submerged in an 80-by-20-foot pool specially dug by the team. The crew partnered with conservators working on the Mary Rose Trust in Portsmouth, England, and the Canadian Conservation Institute in Ottawa, along with the Historical Resource Conservation Branch of the Canadian Parks Service, to learn freshwater preservation techniques. Organic materials like wood and leather are submerged in a food preservative called polyethylene glycol (PEG) and then freeze-dried. Preservationists gently remove oxidized material from metal artifacts using metal tools and special erasers. Bottled and jarred foods and beverages are injected with nitrogen, an inert gas. Shoes, boots, and garments must be restitched since their cotton thread dissolved under water. The preservation process is still in progress at the museum. It was originally estimated that the preservation of the collection would be completed in 2022. Preservation efforts will likely take another 10-12 years, however.
== Partnerships == In 2013 US Fleet Tracking announced the formation of a strategic partnership with AgTrax Technologies, developers of accounting software programs for agri-businesses. The partnership resulted in the integration of AgTrax’s software with US Fleet Tracking’s TotalView system to create an enhanced GPS tracking system that enables real-time monitoring of mobile agricultural equipment. In 2016 US Fleet Tracking established a partnership with Gorilla Safety, a Houston-based company specializing in software for the transportation sector, to create a fully integrated system that combines live GPS tracking with electronic logging features compliant with the Electronic Logging Device (ELD) mandate of the Federal Motor Carrier Safety Administration (FMCSA).
It appears that this gene loss has happened several times independently in evolutionary separated groups of animals. Lack of ghrelin and MBOAT4 may be relevant to the way that these reptiles can live at a low energy demand for months or years. Their fat stores are used at a low level. The presence of many mutations in genes for aspects of mitochondrial function in these animals may also be involved in their reduced energy demand.
== Chemical structure and properties == Retinyl acetate is the acetate ester of all‑trans‑retinol. Its polyene side chain makes the molecule highly lipophilic and sensitive to photo‑oxidation; antioxidants (e.g., tocopherol) and opaque packaging are therefore used to limit degradation in finished products. The compound melts at ~59 °C and is practically insoluble in water but miscible with edible oils and most organic solvents.
Sources: en.wikipedia.org
The ligated mRNA-DNA-puromycin library is translated in Red Nova Lysate (Novagen) or E. coli S30 Extract System (Promega), resulting in peptides covalently linked in cis to the encoding mRNA. The in vitro translation can also be done in a PURE (protein synthesis using recombinant elements) system. PURE system is an E. coli cell-free translation system in which only essential translation components are present. Some components, such as amino acids and aminoacyl-tRNA synthases (AARSs) can be omitted from the system. Instead, chemically acylated tRNA can be added into the PURE system. It has been shown that some unnatural amino acids, such as N-methyl-amino acid accylated tRNA can be incorporated into peptides or mRNA-peptide fusions in a PURE system. After translation, the single-stranded mRNA portions of the fusions will be converted to heteroduplex of RNA/DNA by reverse transcriptase to eliminate any unwanted RNA secondary structures, and render the nucleic acid portion of the fusion more stable. This step is a standard reverse transcription reaction. For instance, it can be done by using Superscript II (GIBCO-BRL) following the manufacturer's protocol.
=== Relationships === In 2012, Collins dated fellow The Only Way Is Essex cast member Charlie King. During their relationship, she had suspicions that King was gay. He later came out in 2014. Following their split, Collins began a relationship with mechanic Rami Hawash, whom she had previously dated in 2011, and the pair became engaged on 25 December 2013; however, the engagement was called off a few weeks later. In November 2014, Collins was assaulted by her then boyfriend, Alexander Moss, at her former home in Warley. Reflecting on the incident in 2017, she said her biggest regret was not pressing charges because she was "too scared to see it through". Collins briefly dated James Argent in 2012, before reuniting with ex-boyfriend, Rami. The pair reconciled in December 2017 when Argent professed his love for Collins during The Only Way Is Essexmas and they were in an on-and-off relationship until July 2020. Argent struggled with cocaine addiction which resulted in the breakdown of their relationship. Collins said Argent's addiction made her feel "suicidal" and caused her to suffer from post-traumatic stress disorder as a result. In December 2020, Collins rekindled her relationship with ex-fiancé, Rami Hawash. They reconnected again after attending a Madonna concert together. In July 2021, Collins confirmed their reunion after she was spotted wearing her engagement ring several months prior.
=== Special precautions === The elderly metabolize benzodiazepines more slowly than younger people and are also more sensitive to the effects of benzodiazepines, even at similar blood plasma levels. Doses for the elderly are recommended to be about half of that given to younger adults and are to be administered for no longer than two weeks. Long-acting benzodiazepines such as clonazepam are not generally recommended for the elderly due to the risk of drug accumulation. The elderly are especially susceptible to increased risk of harm from motor impairments and drug accumulation side effects. Benzodiazepines also require special precaution if used by individuals that may be pregnant, alcohol- or drug-dependent, or may have comorbid psychiatric disorders. Clonazepam is generally not recommended for use in elderly people for insomnia due to its high potency relative to other benzodiazepines. Clonazepam is not recommended for use in those under 18. Use in very young children may be especially hazardous. Of anticonvulsant drugs, behavioural disturbances occur most frequently with clonazepam and phenobarbital. Doses higher than 0.5–1 mg per day are associated with significant sedation. Clonazepam may aggravate hepatic porphyria. Clonazepam is not recommended for patients with chronic schizophrenia. A 1982 double-blinded, placebo-controlled study found clonazepam increases violent behavior in individuals with chronic schizophrenia. Clonazepam has similar effectiveness to other benzodiazepines at often a lower dose.
Duterte also used the US-Philippines Visiting Forces Agreement as leverage in securing vaccines from the United States, threatening to scrap the military pact. In addition, in an apparent effort to help the Philippines gain access to US-developed vaccines, Duterte granted absolute pardon to US soldier Joseph Scott Pemberton, who was serving prison for killing transgender Jennifer Laude in 2014.
Sources: en.wikipedia.org
The use of animal gut strings by musicians can be traced back to the third dynasty of Egypt. In the recent past, strings were made out of lamb gut. With the advent of the modern era, musicians have tended to use strings made of silk, or synthetic materials such as nylon or steel. Some instrumentalists, however, still use gut strings in order to evoke the older tone quality. Although such strings were commonly referred to as "catgut" strings, cats were never used as a source for gut strings. Sheep gut was the original source for natural gut string used in racquets, such as for tennis. Today, synthetic strings are much more common, but the best gut strings are now made out of cow gut. Gut cord has also been used to produce strings for the snares that provide a snare drum's characteristic buzzing timbre. While the modern snare drum almost always uses metal wire rather than gut cord, the North African bendir frame drum still uses gut for this purpose. "Natural" sausage hulls, or casings, are made of animal gut, especially hog, beef, and lamb. The wrapping of kokoretsi, gardoubakia, and torcinello is made of lamb (or goat) gut. Haggis is traditionally boiled in, and served in, a sheep stomach. Chitterlings, a kind of food, consist of thoroughly washed pig's gut. Animal gut was used to make the cord lines in longcase clocks and for fusee movements in bracket clocks, but may be replaced by metal wire. The oldest known condoms, from 1640 AD, were made from animal intestine.
The red-bellied black snake (Pseudechis porphyriacus) is a venomous species native to Australia. The venom of the red-bellied black snake consists of myotoxins, coagulants and also has haemolytic and cytotoxic properties. It also contains weak pre-synaptic neurotoxins. The murine LD50 is 2.52 mg/kg SC. Average venom yield per bite is 37 mg and a maximum yield of 97 mg. Bites from red-bellied black snake are rarely life-threatening due to the snake usually choosing to inject little venom toxin, but are still in need of immediate medical attention. Rate of envenomation is 40–60%, but the untreated mortality rate is less than 1%.
However, the Smith government still professed loyalty to Elizabeth II, and accordingly the document reconstituted Rhodesia as a Commonwealth realm with Elizabeth as "Queen of Rhodesia". The new constitution created the concept of allegiance to the "Constitution of Rhodesia", and introduced the post of Officer Administering the Government, a viceregal figure empowered to sign passed legislation into law on behalf of the monarch if she did not appoint a Governor-General. The Rhodesian Cabinet waited in vain for Wilson's reply for the rest of 9 November and the next day. After briefly meeting Smith late on 10 November, Johnston warned Wilson that evening that the Rhodesians seemed poised to declare independence in the morning. The British prime minister tried repeatedly to call Smith, but did not get through until Smith was already chairing a Cabinet meeting on the independence issue around 08:00 Central Africa Time (06:00 in London) on 11 November. Wilson attempted to talk Smith out of unilateral action by telling him the status quo could continue, and the two argued inconclusively about the proposed Royal Commission. Returning to his Cabinet meeting, Smith reported the conversation to his ministers, and, after debating for a while, the Cabinet came to the conclusion that Wilson was simply attempting to buy more time and that there was no sign of actual progress. Smith asked if Rhodesia should declare its independence, and had each Cabinet minister answer in turn.
== Medical use == In the United States, paliperidone is indicated for the treatment of schizophrenia and for the treatment of schizoaffective disorder as monotherapy and as an adjunct to mood stabilizers and/or antidepressants. In the European Union, paliperidone is indicated for the treatment of schizophrenia in adults and in adolescents fifteen years of age and older and for the treatment of schizoaffective disorder in adults.
The "Cave of the Sixteen sword bearers" ("Höhle der Schwertträger", 十六带剑者窟) is a famous cave with a series of murals showing swordsmen wearing caftans and armed with long sword and daggers. These murals have been carbon dated to 432–538 CE. The swordsmen have also been dubbed the "Tocharian donors". The interpretations of the nationality or ethnicity of the donors have varied. Some authors claim that the donors are indeed Tocharians, an elusive people of the Tarim Basin who spoke the well-documented Tocharian language, the easternmost Indo-European language. According to this thesis, the donors in the murals are of the Indo-European type, wearing Iranian-style clothes and reddish hair. A more recent interpretation is that the sword-bearers are actually Hephthalites, who are known to have occupied the Tarim Basin from 490 to 560 CE, precisely at the time the paintings were made. Kucha was specifically part of their dominion between 502 and 556 CE. The clothing style, the iconography and the physiognomy of the donors are said to be extremely close to those depicted in the paintings of Tokharistan (Bactria), the center of Hephthalite power, at sites such as Balalyk tepe or Dilberjin Tepe. In particular, the coat with single folded lapel is considered as a result of Hephthalite influence, whereas traditional Kuchean coats had two lapels. At present, the most prevalent opinion among academics seems to be that the Hephthalites were initially of Turkic origin. Similar donors can be seen in the Kumtura Caves.
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.
Regulatory treatment varies by country. In the United States, the European Union and Australia it is an unapproved drug and its sale is restricted, while some other jurisdictions list it as prescription-only or controlled. The applicable rules depend on the country of import.