alpha-MSH analog comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2025-08-06. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Analog of alpha-melanocyte-stimulating hormone |
| Primary receptor family | Melanocortin receptors MC1R through MC5R | Binding is not subtype-selective |
| Development period | 1980s | Synthesized during pigmentation and appetite research |
| Regulatory status | Not an approved medicine | No major regulator has authorized human use |
| Related compound | Afamelanotide | Linear analog studied for photoprotection |
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.
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.
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.
Reversed-phase high-performance liquid chromatography is the routine method for purity assessment. Peptides absorb near 214 nm because of the peptide bond, and a gradient of acetonitrile in water separates the intact peptide from deletion sequences, oxidised products, and earlier-eluting fragments at neutral pH. Electrospray ionisation mass spectrometry provides an orthogonal check: the measured mass must agree with the theoretical value. Amino acid analysis and peptide mapping confirm structure but are used less often. Reference standards remain scarce because the peptide is not described in any pharmacopoeia.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its sequence incorporates modified residues that increase potency and extend biological activity relative to the native hormone. The compound binds receptors of the melanocortin family and is examined mainly in laboratory research. It does not occur naturally and exists only as a manufactured chemical entity produced by solid-phase synthesis.
The peptide was developed during the 1980s by researchers investigating melanocortin signalling and skin pigmentation pathways. Early work focused on analogues of alpha-melanocyte-stimulating hormone that would resist enzymatic breakdown more effectively than the parent molecule. Melanotan-2 emerged from that programme as a shortened, cyclised variant. Reports describing its synthesis and receptor activity later appeared in the scientific literature. Commercial availability grew through unregulated channels rather than through pharmaceutical approval.
Structurally, Melanotan-2 retains the core recognition motif of alpha-melanocyte-stimulating hormone while adding a lactam bridge that links two side chains and constrains the molecule into a ring. This modification lowers susceptibility to enzymatic degradation. The compound acts as an agonist at melanocortin receptors, particularly subtypes associated with melanin production. Because the same receptor family influences several physiological processes, researchers note that its activity is not confined to pigmentation alone. Receptor selectivity continues to be examined in published studies.
Published research on the compound remains limited. Much of the human data comes from small, early-stage studies rather than large controlled trials, and several questions about effects and variability between individuals remain open. Investigators have examined receptor activity, pigment pathways, and related physiological responses in laboratory and animal models. Findings from those models do not automatically translate to human outcomes. Reviews frequently note the scarcity of rigorous clinical evidence and call for better-characterized study material.
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.
Alprazolam has typically caused anterograde amnesia effects (inability to recall new events), but a study conducted on mice by the Department of Pharmaceutical Sciences and Drug Research at Punjabi University has also determined that alprazolam can produce retrograde amnesic effects (inability to remember events occurring before amnesia). One 2016 study found that "chronic administration of alprazolam affects memory but attentive and psychomotor performance remained unaffected". A 2016 randomized controlled trial stated that "overall, long-term benzodiazepine users may not be in their full cognitive state upon withdrawal". Similarly, a 2017 meta-analysis concluded that "a range of neuropsychological functions are impaired as a result of long-term benzodiazepine use, and that these are likely to persist even following withdrawal".
== History == Nemolizumab was invented by Chugai, who sold an exclusive license for the drug's development and worldwide marketing (except Japan and Taiwan) to Galderma in 2016. The US Food and Drug Administration (FDA) approved nemolizumab for the treatment of prurigo nodularis based on evidence from two clinical trials (OLYMPIA 1 and OLYMPIA 2) of 560 participants with prurigo nodularis. The trials were conducted at 132 sites in 16 countries including Austria, Belgium, Canada, Denmark, France, Netherlands, Germany, Hungary, Italy, Poland, South Korea, Spain, Sweden, Switzerland, the United Kingdom, and the United States. The trials included 99 participants inside the United States. Among the 560 enrolled participants, all of them were evaluated for efficacy (intent-to-treat population) and 556 participants were evaluated for safety. In both trials, participants with prurigo nodularis were randomized to receive nemolizumab or placebo. Participants weighing less than 90 kilograms (200 lb) in the nemolizumab group received subcutaneous injections of nemolizumab 60 mg at week 0, followed by 30 mg injections every four weeks. Participants weighing 90 kilograms (200 lb) or more in the nemolizumab group received subcutaneous injections of nemolizumab 60 mg at week 0 and every four weeks.
high-throughput and high-fidelity quantification and sub-cellular localization (high-content screening, cytohistopathology, Bioimage informatics) morphometrics clinical image analysis and visualization determining the real-time air-flow patterns in breathing lungs of living animals quantifying occlusion size in real-time imagery from the development of and recovery during arterial injury making behavioral observations from extended video recordings of laboratory animals infrared measurements for metabolic activity determination inferring clone overlaps in DNA mapping, e.g. the Sulston score
The machines are designed for Offshore wind power in Brittany, the UK, and Normandy. Other industries are dispersed throughout the Le Havre agglomeration: the Brûlerie du Havre, which belongs to Legal-Legoût, located in the district of Dollemard that roasts coffee, Sidel located both in the industrial area of Port of Le Havre and Octeville-sur-Mer designs and manufactures blow moulding machines and complete filling line machines for plastic bottles.
== Biosynthesis == Little gastrin I is synthesized from a 101-amino acid precursor protein called preprogastrin. A signal peptide of 21 amino acids is removed in the Endoplasmic reticulum, producing the 80-amino acid intermediate progastrin. Progastrin is then cleaved at specific site by Proprotein convertase as it moves through the Golgi apparatus toward secretory vesicles, producing gastrin-34 and gastrin-17 as the two major biologically active end products. In the normal human stomach, around 85% of amidated gastrin in the antral mucosa is in the G-17 form.
Sources: en.wikipedia.org
=== Cited texts === Benjamin, Denis R. (1995). Mushrooms: Poisons and Panaceas—A Handbook for Naturalists, Mycologists and Physicians. New York: WH Freeman and Company. ISBN 978-0-7167-2600-5. Jordan, Peter; Wheeler, Steven (2001). The Ultimate Mushroom Book. London: Hermes House. ISBN 978-1-85967-092-7. Zeitlmayr, Linus (1976). Wild Mushrooms: An Illustrated Handbook. Hertfordshire: Garden City Press. ISBN 978-0-584-10324-3.
Scabies (, SKAY-beez; also sometimes known as the seven-year itch) is a contagious human skin infestation by the tiny (0.2–0.45 mm) mite Sarcoptes scabiei, variety hominis. The word is from Latin: scabere, lit. 'to scratch'. It is a particular public health problem in crowded settings such as care homes, schools, refugee camps, prisons, and hospitals. The most common symptoms are severe itchiness and a pimple-like rash. Occasionally, tiny burrows may appear on the skin from eggs that are about to hatch. In a first-ever infection, the infected person usually develops symptoms within three weeks. During a second infection, symptoms may begin within 24 hours. These symptoms can be present across most of the body or just in certain areas such as the wrists, between fingers, or along the waistline. The head may be affected, but this is typically only in young children. The itch is often worse at night. Scratching may cause skin breakdown and an additional bacterial infection in the skin. Various names have been given to this condition and the name "seven year itch" has been recorded in many documents from the 1800s. Although the 1952 play The Seven Year Itch and modern treatment methods have generally changed this name to refer to human relationships, the condition was historically very difficult to treat. Scabies is caused by infection with the female mite Sarcoptes scabiei var. hominis, an ectoparasite. The mites burrow into the skin to live and deposit eggs. The symptoms of scabies are due to an allergic reaction to the mites.
In the US, Aducanumab is indicated for the treatment of Alzheimer's disease. In July 2021, the US Food and Drug Administration (FDA) limited the indication to people with mild cognitive impairment or mild dementia stage of disease, the population in which treatment was initiated in clinical trials. Aducanumab is a monoclonal IgG1 antibody that binds to the amyloid beta protein at amino acids 3–7, which is posited to result in slowing the progression of Alzheimer's disease. The mechanism is based on the amyloid hypothesis, which posits that amyloid proteins cause Alzheimer's disease, hence removing amyloid should slow the progression of the disease. How the antibody accesses the plaques is under active research. One mechanism suggests the plaques are exposed to the lumen of blood vessels and the antibody accesses the plaques from the lumen side. This assumes the plaque formed as a result of a leaky blood brain barrier and may also explain why there is hemorrhage after the plaques are removed. The most common serious adverse reactions reported are:
In addition, if a piece of wood is used for multiple purposes, there may be a significant delay between the felling of the tree and the final use in the context in which it is found. This is often referred to as the "old wood" problem. One example is the Bronze Age trackway at Withy Bed Copse, in England; the trackway was built from wood that had clearly been worked for other purposes before being re-used in the trackway. Another example is driftwood, which may be used as construction material. It is not always possible to recognize re-use. Other materials can present the same problem: for example, bitumen is known to have been used by some Neolithic communities to waterproof baskets; the bitumen's radiocarbon age will be greater than is measurable by the laboratory, regardless of the actual age of the context, so testing the basket material will give a misleading age if care is not taken. A separate issue, related to re-use, is that of lengthy use, or delayed deposition. For example, a wooden object that remains in use for a lengthy period will have an apparent age greater than the actual age of the context in which it is deposited.
Sources: en.wikipedia.org
At the end of its 2013 fiscal year, Burger King was the second largest chain of hamburger fast food restaurants in terms of global locations, behind industry bellwether McDonald's, which had 32,400 locations. At the end of 2014, Burger King ranked fourth among US food chains in terms of US sales, behind McDonald's, Starbucks, and Subway. Burger King now has over 12,000 stores worldwide. In January 2024, Restaurant Brands International, the owner of the brand, announced it would purchase the largest franchisee of the chain, Carrols Restaurant Group, for around $1 billion. At the time of the announcement, Carrols had 1,022 Burger King locations (along with 60 Popeyes locations). The goal was to remodel 600 of the restaurants, then sell them back to franchisees over five to seven years. The move represented a departure from the existing model of largely franchising locations.
The Hitachi 917 is an automated biochemistry analyser utilised at medical laboratories to process biological fluid specimens, such as urine, cerebrospinal fluid, and most commonly, blood. Manufactured by Boehringer Mannheim, the Hitachi 917 is a commonly used routine chemical bichromatic analyser. Capable of doing 1200 test/hour with ISE, it is a popular choice among small to medium size laboratories.
=== Transcriptional variants === So far, three different transcription variants (TVs) have been described for CK1δ in humans (Homo sapiens), mice (Mus musculus), and rats (Rattus norvegicus), which are highly homologous. The alignment of all CK1δ sequences of all organisms shows a high homology in the first 399 amino acids, except for position 381. While the human transcription variants are using isoleucine, the mouse and rat sequences incorporate a valine instead. The only exception is rat TV3, which is also transcribing its nucleotide sequence into an isoleucine. After position 399, three different general structures can be observed. The first variant consists of 415 amino acids across all three organisms and is called TV1 in human and rat, while the murine counterpart is named CRAa. The shortest group of sequences consists of 409 amino acids: TV2 in humans and rats, CRAc in mice. The longest variant consists of 428 amino acids in rat (TV3) and mice (CRAb), while the human (TV3) variant is missing the second to last amino acid (threonine), resulting in a protein of a length of 427 amino acids. The various transcription variants are based on a different usage of the exons that are encoding for CSNK1D. The whole gene consists of eleven different exons and is located in humans on chromosome 17 at position 17q25.3. CSNK1D has a length of 35kb and is overlapping with the gene Slc16a3. The intersecting part is exon 11, which is located downstream of exon 10. However, it does not interfere with Slc16a3 since it is located in a non-coding area.
Sources: en.wikipedia.org
No regulator in a major market has approved it for human use. It appears in research settings and in products marketed outside pharmacy channels. Legal status for personal possession varies by country.
Afamelanotide is a linear analog that has received approval in some jurisdictions for a specific photoprotection indication. Melanotan II is cyclic and less selective across melanocortin receptors. The two are related but are not interchangeable in regulatory or clinical terms.
A compound that activates several receptor subtypes may produce effects beyond pigmentation. Selectivity influences which tissues respond and shapes the side-effect profile described in reports. Designing subtype-selective analogs is a stated goal of melanocortin research.
The lyophilised solid is best kept cold, dry and dark, typically at minus twenty degrees Celsius. Moisture and repeated warming cycles are the main causes of degradation. Solutions prepared from the powder are less stable and are normally used quickly.