prescription control raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-12-22. Anything still debated is marked as such rather than presented as settled.
Regulatory treatment varies by country. In the United States the peptide is not approved as a medicine, and products offered for human use may be treated as unapproved new drugs; some states also restrict sale. Australia, the United Kingdom, and European Union member states apply comparable restrictions to unapproved peptide products. Border agencies have seized shipments labelled as research chemicals. Classification may change over time, and the legal position for personal importation is not clearly settled in most published guidance.
Lyophilised melanotan-2 is supplied as a solid, which is more stable than a solution. The material is hygroscopic, so weighing is done quickly, in low humidity, with the container kept sealed. Reconstitution usually uses water for injection or bacteriostatic water, added down the wall of the vial to limit foaming. A reconstituted solution is held at 2 to 8 °C and kept away from light. Repeated freezing and thawing of the same vial is avoided because ice crystal formation and concentration effects degrade the peptide.
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 |
|---|---|---|
| Lyophilised storage | −20 °C, dry, protected from light | Vials are sealed and allowed to reach room temperature before opening |
| Reconstituted storage | 2 to 8 °C, protected from light | Short-term holding; avoid repeated freeze-thaw cycles |
| Reconstitution solvent | Water for injection or bacteriostatic water | Added slowly along the vial wall to reduce foaming and shear |
| Purity measurement | RP-HPLC with area normalisation | Acetonitrile-water gradient monitored at roughly 214 nm |
| Identity confirmation | Electrospray ionisation mass spectrometry | Observed mass compared against the calculated peptide mass |
Melanotan-2 appears on the World Anti-Doping Agency prohibited list within the peptide hormone class, and several national regulators treat it as an unapproved prescription substance. Some countries restrict importation or sale for personal use. Because the compound is widely traded as a research chemical, the practical legal picture differs between jurisdictions and shifts over time. Human safety data covering long periods are limited, and whether repeated pigmentation changes carry any lasting risk to melanocytes remains an open question.
Freeze-dried melanotan-2 is normally kept as a desiccated powder at minus twenty degrees Celsius or lower, shielded from light and moisture. Peptides of this size degrade through hydrolysis, oxidation and deamidation, and each pathway accelerates as temperature and water activity rise. Repeated freeze-thaw cycles promote aggregation and loss of material, so aliquoting a stock solution before freezing is standard laboratory practice. Once dissolved, the solution is markedly less stable than the powder. In laboratory work, solutions are generally refrigerated and used within days rather than kept for months.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or oxidised impurities. Mass spectrometry, most often coupled to liquid chromatography, confirms molecular mass and detects substitutions that chromatography alone may miss. Amino acid analysis and peptide mapping supply additional structural evidence, while nuclear magnetic resonance is reserved for full structural confirmation. Laboratories that examine samples sold online report wide variation in actual content, with some vials containing little or none of the labelled material.
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.
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.
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.
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.
=== Aesthetic medicine === Platelet-rich plasma therapy is a minimally invasive procedure that may be used in aesthetic medicine to treat skin conditions such as the removal of wrinkles, the reduction of lines, and improvement of blemishes, and hair loss. Concentrated PRP solution is injected into the treatment area to target damaged cells and tissues. The growth factors and proteins in PRP aid in rejuvenating the skin, and improving the condition of the scalp stimulating hair growth.
Red ear syndrome (RES) is a rare disorder of unknown etiology which was originally described in 1994. The defining symptom of red ear syndrome is redness of one or both external ears, accompanied by a burning sensation. A variety of treatments have been tried with limited success. Red ears are also often a classic symptom of relapsing polychondritis (RP), a rare autoimmune disease that attacks various cartilage areas (and sometimes other connective tissue areas) in the body; research estimates that RP affects 3-5 people per million. Red ears in RP indicate inflamed cartilage (and sometimes the skin of the outer ear along with the cartilage) and often cause moderate to extreme pain during “flares” of the disease, which can be acute and/or chronic. Red ears in RP can be bilateral or unilateral, and are described as “earlobe sparing” due to the lack of cartilage in the earlobe. Prolonged inflammation can eventually result in deteriorated ear cartilage (often described as “cauliflower ear” or “floppy ear”), and even partial or total loss of hearing.
== Function == Spermidine synchronizes an array of biological processes, (such as Ca2+, Na+, K+ -ATPase) thus maintaining membrane potential and controlling intracellular pH and volume. Spermidine regulates biological processes, such as Ca2+ influx by glutamatergic N-methyl-D-aspartate receptor (NMDA receptor), which has been associated with nitric oxide synthase (NOS) and cGMP/PKG pathway activation and a decrease of Na+,K+-ATPase activity in cerebral cortex synaptosomes. Spermidine is a longevity agent in mammals due to various mechanisms of action, which are just beginning to be understood. Autophagy is the main mechanism at the molecular level, but evidence has been found for other mechanisms, including inflammation reduction, lipid metabolism, and regulation of cell growth, proliferation, and death. Spermidine has been theorized to promote autophagy via the MAPK pathway by inhibiting phosphorylation of raf, or possibly by inhibiting cytosolic autophagy-related protein acetylation by EP300 and thereby increasing acetylation of tubulin. Spermidine is known to regulate plant growth, assisting the in vitro process of transcribing RNA, and inhibition of NOS. Also, spermidine is a precursor to other polyamines, such as spermine and thermospermine, some of which contribute to tolerance against drought and salinity in plants. Spermidine has been tested and discovered to encourage hair shaft elongation and lengthen hair growth.
== Treatment == Treatment of GAMT deficiency focuses on restoration of depleted brain creatine with oral creatine supplementation in pharmacologic doses, and removal of toxic intermediate GAA via ornithine supplementation and arginine- or protein-restricted diet. Sodium benzoate supplementation is also sometimes used to decrease GAA levels. All patients are reported to benefit from creatine supplementation, with possible improvements or stabilization in symptoms. Seizures appear to reduce more with dietary arginine restriction and ornithine supplementation. Despite treatment, none of the patients have been reported to return to completely normal developmental level, if significant damage had taken place before treatment. Prior to the addition of GAMT deficiency to newborn screening panels, younger siblings of affected individuals may have been tested at birth and treated early. This early treatment can result in outcomes that are very close to normal.
and an honorary citizen of the cities of Frankfurt am Main and Göttingen in 1959, and of Berlin (1968). Hahn was made an Officer of the Ordre National de la Légion d'Honneur of France (1959), and was awarded the Grand Cross First Class of the Order of Merit of the Federal Republic of Germany (1959). In 1966, US President Lyndon B. Johnson and the United States Atomic Energy Commission (AEC) awarded Hahn, Lise Meitner and Fritz Strassmann the Enrico Fermi Award. The diploma for Hahn bore the words: "For pioneering research in the naturally occurring radioactivities and extensive experimental studies culminating in the discovery of fission." He received honorary doctorates from the University of Gottingen, the Technische Universität Darmstadt, the Goethe University Frankfurt in 1949, and the University of Cambridge in 1957. Objects named after Hahn include:
Sources: en.wikipedia.org
=== Part one === In 1897, in Idris, ten-year-old Lucie Herondale, daughter of Shadowhunter William "Will" Herondale, and half warlock/half Shadowhunter Theresa "Tessa" Gray, gets lost in the forest. She finds her way back with the help of a mysterious young boy. Six years later, in 1903, James Herondale and his friends, his parabatai Matthew Fairchild (son of Charlotte Fairchild), Thomas Lightwood, and Christopher Lightwood, defeat the first demon they have seen in a year. The demon recognizes James, who falls into the shadow realm (a unique power as a result of his warlock heritage) for the first time in 3 years. Meanwhile, Cordelia Carstairs enters the London society along with her brother Alastair and mother Sona. Her father has been arrested for supposedly mishandling a vampire raid, and the Carstairs wish to make powerful allies in London to save their reputation. The Carstairs are greeted by Tessa, James (Cordelia's childhood friend who she has a crush on), and Lucie (James' sister). Cordelia believes that her feelings for James might be requited. At the next day's ball, James requests Cordelia dance with him, but disappoints her when he suddenly leaves to greet Grace Blackthorn, the adopted ward of Tatiana Blackthorn. James met Grace in 1899, and has been in love with her since he was 13 years old. Lucie sees the mysterious boy from her childhood, who reveals himself to be the ghost of Jesse Blackthorn, the late son of Tatiana. His mother asked Downworlders to preserve his body, so his spirit has remained trapped in the in-between.
=== Asia === B. burgdorferi sensu lato-infested ticks are being found more frequently in Japan, as well as in northwest China, Nepal, Thailand and far eastern Russia. Borrelia has also been isolated in Mongolia.
date-range is the range of dates corresponding to the given confidence level confidence indicates the confidence level for the given date range. For example, "cal 1220–1281 AD (1σ)" means a calibrated date for which the true date lies between AD 1220 and AD 1281, with a confidence level of '1 sigma', or approximately 68%. Calibrated dates can also be expressed as "BP" instead of using "BC" and "AD". The curve used to calibrate the results should be the latest available IntCal curve. Calibrated dates should also identify any programs, such as OxCal, used to perform the calibration. In addition, an article in Radiocarbon in 2014 about radiocarbon date reporting conventions recommends that information should be provided about sample treatment, including the sample material, pretreatment methods, and quality control measurements; that the citation to the software used for calibration should specify the version number and any options or models used; and that the calibrated date should be given with the associated probabilities for each range.
Abu Omar al-Shishani Abu Sayfullah Shishani Abu Said Shishani Ahmad Shishani Abu Abdullah Shishani Al Bara Shishani Abu Ibrahim Shishani Abu Umar Grozny Musa Abu Yusuf Shishani Hayrullah Shishani Abdullah Shishani Abu Hafs Shishani Adam Shishani Abdul-Halim Shishani Hattab Shishani Abdullah Abu Muhammad Shishani Abdul-Vahhab Shishani Muhammad Shishani Abu Hisham Shishani Abu Anas Shishani Abu Shamil Shishani Jundullah Shishani
=== Pre-1900 === Early film (pre-1900) was dominated by the novelty of showing an event. Single-shot moments were captured on film, such as a train entering a station, a boat docking, or factory workers leaving work. These short films were called "actuality" films; the term "documentary" was not coined until 1926. Many of the first films, such as those made by Auguste and Louis Lumière, were a minute or less in length, due to technological limitations. Films showing many people (for example, leaving a factory) were often made for commercial reasons: the people being filmed were eager to see, for payment, the film showing them. One notable film clocked in at over an hour and a half, The Corbett-Fitzsimmons Fight. Using pioneering film-looping technology, Enoch J. Rector presented the entirety of a famous 1897 prize-fight on cinema screens across the United States. In May 1896, Bolesław Matuszewski recorded on film a few surgical operations in Warsaw and Saint Petersburg hospitals. In 1898, French surgeon Eugène-Louis Doyen invited Matuszewski and Clément Maurice to record his surgical operations. They started in Paris a series of surgical films sometime before July 1898. Until 1906, the year of his last film, Doyen recorded more than 60 operations. Doyen said that his first films taught him how to correct professional errors he had been unaware of.
Sources: en.wikipedia.org
=== Sweat drug screen === Sweat patches are attached to the skin to collect sweat over a long period of time (up to 14 days). These are used by child protective services, parole departments, and other government institutions concerned with drug use over long periods, when urine testing is not practical. There are also surface drug tests that test for the metabolite of parent drug groups in the residue of drugs left in sweat. An example of a rapid, non-invasive, sweat-based drug test is fingerprint drug screening. This 10 minute fingerprint test is in use by a variety of organisations in the UK and beyond, including within workplaces, drug treatment and family safeguarding services at airport border control (to detect drug mules) and in mortuaries to assist in investigations into cause of death.
== History == The impact factor was devised by Eugene Garfield, the founder of the Institute for Scientific Information (ISI) in Philadelphia. Impact factors began to be calculated yearly starting from 1975 for journals listed in the Journal Citation Reports (JCR). ISI was acquired by Thomson Scientific & Healthcare in 1992, and became known as Thomson ISI. In 2018, Thomson-Reuters spun off and sold ISI to Onex Corporation and Baring Private Equity Asia. They founded a new corporation, Clarivate, which continued publishing the JCR.
The duration of estradiol esters in oil solution by intramuscular injection is dose-dependent. With estradiol valerate, it is reported that a dose of 5 mg has a duration of 7 to 8 days, 10 mg a duration of 10 to 14 days, 40 mg a duration of 2 to 3 weeks, and 100 mg a duration of 3 to 4 weeks. High doses of estradiol valerate, such as 40 mg per week, can achieve pregnancy levels of estradiol. A study of pseudopregnancy with intramuscular injections of 40 mg/week estradiol valerate and 250 mg/week hydroxyprogesterone caproate observed estradiol levels of about 2,500 to 3,000 pg/mL.
Chilling revelations of torture, rape, massacres, extermination were revealed through the 2014 Caesar Report, which documented photographic evidences of industrial-scale atrocities occurring in Syrian military prisons. The report documented a total of 55,000 digital images of tortured or dismembered human bodies of around 11,000 detainees. Describing some of the torture techniques unleashed on Syrians held captive in military prisons, the military defector Caesar states: "It was very clear that they were tortured, not tortured for a day or two, tortured for many, many long months. They were emaciated bodies, purely skeletons. There were people, most of them had their eyes gouged out. There was electrocution, you could tell by the dark spots on their body that was used there. There was utilization of knives and also big cables and belts that was used to beat them. And so, we could see every type of torture on the bodies of these individuals. 'Every type of torture,' but the depravity of the gouged eyes leaves to the imagination how maiming was calculated to coerce information. By 2013, the bodies overflowed the morgues and spilled across a parking garage at a military hospital."In 2023, Canada and Netherlands jointly filed a lawsuit against the Assad regime at the International Court of Justice (ICJ); charging Assad with ordering torture, rapes and other de-humanising tactics on hundreds of thousands of detainees in Syrian prison networks, including women and children.
Sources: en.wikipedia.org
Low temperature slows hydrolysis and oxidation, the two main routes by which the peptide backbone and side chains are modified. A lyophilised powder stored at −20 °C is more stable than one kept at room temperature, and once the material is dissolved the degradation rate rises, making refrigeration more important.
Liquid chromatography coupled to mass spectrometry is the most common approach because it combines a retention time with a mass measurement. A chromatographic peak alone cannot establish which peptide is present, so mass determination or amino acid analysis is used as an orthogonal confirmation alongside the separation.
This depends on buffer, pH, and concentration, and published stability data for this peptide are limited. In practice laboratories work through a refrigerated solution within a few weeks and discard samples that show cloudiness or visible particles. Freezing and thawing repeatedly is generally discouraged.
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.