Everything below concerns cyclic heptapeptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-01-19. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Quality assessment of research-grade peptide rests mainly on reversed-phase high-performance liquid chromatography for purity and on mass spectrometry for identity confirmation. A single main peak above a stated threshold, commonly ninety-eight percent by peak area, is the usual release criterion applied by suppliers. Independent analyses commissioned by laboratories and consumer organisations have repeatedly reported discrepancies between label claims and measured content, including truncated sequences, residual trifluoroacetate, and lower-than-declared peptide mass. Those findings do not establish that every supplier is unreliable, but they indicate that purity figures printed on a vial are claims requiring verification rather than settled facts.
Regulatory treatment varies by jurisdiction and has changed over time. In several countries the peptide is handled as an unapproved prescription medicine, and import or sale for human use is restricted, while elsewhere it falls under poisons or controlled-substance schedules. Enforcement activity against online vendors has been reported in Australia, New Zealand, the United Kingdom and the United States. Scholarly writing discusses melanotan-2 chiefly as an experimental tool and as a case study in unregulated peptide supply, and its precise legal position in any given country should be checked against current national schedules.
| Property | Value | Notes |
|---|---|---|
| Compound class | Synthetic cyclic heptapeptide | Alpha-MSH analogue containing a D-phenylalanine residue |
| Molecular formula | C50H69N15O9 | Average molecular mass approximately 1024.2 g/mol |
| Appearance | White to off-white lyophilised powder | Normally supplied as a freeze-dried solid in a sealed vial |
| Solubility | Freely soluble in water and polar solvents | Dissolves readily in aqueous buffers and in alcohol-water mixtures |
| Receptor targets | MC1R, MC3R, MC4R, MC5R | Acts as a non-selective melanocortin receptor agonist |
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.
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.
Lyophilised peptide powder is comparatively stable when kept dry, cold and protected from light. Once dissolved, the molecule is exposed to hydrolysis, oxidation and microbial growth, and degradation accelerates at higher temperatures and in alkaline solution. Repeated freeze-thaw cycles concentrate solutes and promote aggregation. Handling guidance for research peptides commonly clusters around freezer temperatures for powder and short refrigerated use for reconstituted solutions, with pH control and sterile technique applied throughout.
Verification of a purchased sample requires documentation linking a batch to a certificate of analysis, and that document should be read for the methods used rather than the headline purity figure. A single chromatographic percentage does not establish identity. Independent laboratories can perform identity and content assays, but no such test establishes that a product is suitable for human use. Claims about efficacy rest largely on small, early studies rather than on replicated controlled trials, and that gap remains open.
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.
Receptor studies place melanotan-2 among non-selective melanocortin agonists, binding MC1R, MC3R, MC4R and MC5R rather than a single subtype. Activation of MC1R on cutaneous melanocytes raises tyrosinase activity and shifts pigment synthesis toward eumelanin, which is darker and more photostable than pheomelanin. Central receptors, particularly MC4R, are associated with appetite suppression and with reported effects on sexual function. Because subtype selectivity is low, the same molecule engages pigment, metabolic and vascular pathways at once, and this breadth is a common explanation offered for the range of adverse events described in user reports.
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.
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.
== Dosage and administration == The drug and its generic counterparts are supplied in packages of 12, and available in two strengths: Each B&O Supprettes suppository #15 A contains 16.2 mg (1/4 grain) of belladonna and 30 mg (1/2 grain) of opium. Each B&O Supprettes suppository #16 A contains 16.2 mg of belladonna and 60 mg (1 grain) of opium. The usual dose is one suppository rectally once or twice daily PRN - (as needed), not to exceed four Supprettes in a 24-hour period. In the United States, B&O Supprettes is a Schedule II drug under the Controlled Substances Act of 1970; a written prescription is mandatory, and no refills are permitted. Refrigerated storage is preferable, but not required. Most pharmacies consider B&O Supprettes to be a "special order" item, and as such are not normally kept in inventory. Compounding pharmacies have the capability of producing a generic form of the medication, and can modify the dosage(s) of the active ingredients (for pediatric or elderly patients, and those with chronic kidney disease) or the carrier (usually substituting cocoa butter) to best meet the needs of the patient at the request of the prescriber.
== History == Golden Harvest InfoTech Limited was established in 2000. It is a software export-oriented company. Golden Harvest started manufacturing frozen food in 2006. Golden Harvest founded Taher Ahmed Choudhury Charitable Hospital in 2006 in Bhadeshwar Union, Golapganj Upazila, Sylhet District. Golden Harvest Developers Limited was established in 2009. In January 2011, Golden Harvest Agro was given an A grade by the British Retail Consortium. Golden Harvest Group established Golden Harvest Foods Limited in 2012 to manufacture snacks such as chips and chanachur. It signed an agreement with Nippon Express to launch a joint venture company in Bangladesh. In October 2012, Golden Harvest Agro Industries received permission for their IPO on the Dhaka Stock Exchange. In 2014, Golden Harvest launched a cold chain network with funding from the United States Agency for International Development (USAID). It also received support from the Cold Chain Bangladesh Alliance. Golden Harvest is a sponsor of Dhaka Art Summit, of which Rajeeb Samdani is the founder. In March 2018, Golden Harvest signed an agreement with Jubilant FoodWorks to launch Domino's Pizza in Bangladesh. The first branch was opened in Dhanmondi on 15 March 2019 under a joint venture company called Jubilant Golden Harvest Limited. During the COVID-19 pandemic in Bangladesh, sales of frozen food increased for Golden Harvest. Frozen Paratha and bread sales increased while frozen snacks such as samosa, sausages and ice cream declined dramatically.
Regarding the positive roles of film in education, a case study analyzing students in medical fields found that the appropriate use of movies can provide helpful ideas in applying practical skills related to the medical fields, such as medical ethics, doctor-patient relationships, and mental illness. Celebrity Disclosures Celebrities' influences and their own personal experiences with mental illness can help in decreasing the stereotypes and stigma surrounding mental illness. Stars, including Lady Gaga, Serena Williams, Adele, and Dwayne Johnson, have recently disclosed their mental health journeys. Celebrities disclosing their personal experiences can help inform the public about symptoms and services regarding mental health, allowing mental health struggles to feel more normal and accepted. According to the social learning theory, people often adopt behaviors by observing others, especially celebrities, and seeing the outcomes of their actions. When a celebrity reveals their mental health struggles and remains successful and respected, it can help reduce the fear of facing negative consequences for sharing personal experiences.
=== Sources === Ellis, Richard; McCosker, John E. (1991). Great White Shark. Stanford University Press. ISBN 0-8047-2529-2. Klimley, A. Peter; Ainley, David G., eds. (1996). Great White Sharks: The Biology of Carcharodon carcharias. Academic Press. ISBN 0-12-415031-4. Civard-Racinais, Alexandrine (2012). Great White Shark: Myth and Reality. Firefly. ISBN 978-1-77085-102-3. Domeier, Michael L., ed. (2012). Global Perspectives on the Biology and Life History of the White Shark. CRC Press. ISBN 978-1-4398-4840-1. Skomal, Greg (2023). The Great White Shark Handbook. Cider Mill Press. ISBN 978-1-60433-771-6.
Sources: en.wikipedia.org
==== Vitamin D2 ==== Plants Alfalfa (Medicago sativa subsp. sativa), shoot: 4.8 μg (192 IU) vitamin D2, 0.1 μg (4 IU) vitamin D3 Fungus, from USDA nutrient database, per 100 g: Mushrooms, portabella, exposed to ultraviolet light, raw: Vitamin D2: 11.2 μg (446 IU) Mushrooms, portabella, exposed to ultraviolet light, grilled: Vitamin D2: 13.1 μg (524 IU) Mushrooms, shiitake, dried: Vitamin D2: 3.9 μg (154 IU) Mushrooms, shiitake, raw: Vitamin D2: 0.4 μg (18 IU) Mushrooms, portabella, raw: Vitamin D2: 0.3 μg (10 IU) Mushroom powder, any species, illuminated with sunlight or artificial ultraviolet light sources Vitamin D2, or ergocalciferol is found in fungus (except alfalfa which is a plantae) and created from viosterol, which in turn is created when ultraviolet light activates ergosterol (which is found in fungi and named as a sterol from ergot). Any UV-irradiated fungus including yeast form vitamin D2. Human bioavailability of vitamin D2 from vitamin D2-enhanced button mushrooms via UV-B irradiation is effective in improving vitamin D status and not different from a vitamin D2 supplement according to study. For example, vitamin D2 from UV-irradiated yeast baked into bread is bioavailable. By visual assessment or using a chromometer, no significant discoloration of irradiated mushrooms, as measured by the degree of "whiteness", was observed making it hard to discover if they have been treated without labeling. Claims have been made that a normal serving (approx.
The origins of the concept of hotspots lie in the work of J. Tuzo Wilson, who postulated in 1963 that the formation of the Hawaiian Islands resulted from the slow movement of a tectonic plate across a hot region beneath the surface. It was later postulated that hotspots are fed by streams of hot mantle rising from the Earth's core–mantle boundary in a structure called a mantle plume. Whether or not such mantle plumes exist has been the subject of a major controversy in Earth science, but seismic images consistent with evolving theory now exist. At any place where volcanism is not linked to a constructive or destructive plate margin, the concept of a hotspot has been used to explain its origin. A review article by Courtillot et al. listing possible hotspots makes a distinction between primary hotspots coming from deep within the mantle and secondary hotspots derived from mantle plumes. The primary hotspots originate from the core/mantle boundary and create large volcanic provinces with linear tracks (Easter Island, Iceland, Hawaii, Afar, Louisville, Reunion, and Tristan confirmed; Galapagos, Kerguelen and Marquersas likely). The secondary hotspots originate at the upper/lower mantle boundary, and do not form large volcanic provinces, but island chains (Samoa, Tahiti, Cook, Pitcairn, Caroline, MacDonald confirmed, with up to 20 or so more possible). Other potential hotspots are the result of shallow mantle material surfacing in areas of lithospheric break-up caused by tension and are thus a very different type of volcanism.
=== Murine === Initial therapeutic antibodies were murine analogues (suffix -omab). These antibodies have: a short half-life in vivo (due to immune complex formation), limited penetration into tumour sites and inadequately recruit host effector functions. Chimeric and humanized antibodies have generally replaced them in therapeutic antibody applications. Understanding of proteomics has proven essential in identifying novel tumour targets. Initially, murine antibodies were obtained by hybridoma technology, for which Jerne, Köhler and Milstein received a Nobel prize. However the dissimilarity between murine and human immune systems led to the clinical failure of these antibodies, except in some specific circumstances. Major problems associated with murine antibodies included reduced stimulation of cytotoxicity and the formation of complexes after repeated administration, which resulted in mild allergic reactions and sometimes anaphylactic shock. Hybridoma technology has been replaced by recombinant DNA technology, transgenic mice and phage display.
== Methods == Bisulfite sequencing applies routine sequencing methods on bisulfite-treated genomic DNA to determine methylation status at CpG dinucleotides. Other non-sequencing strategies are also employed to interrogate the methylation at specific loci or at a genome-wide level. All strategies assume that bisulfite-induced conversion of unmethylated cytosines to uracil is complete, and this serves as the basis of all subsequent techniques. Ideally, the method used would determine the methylation status separately for each allele. Alternative methods to bisulfite sequencing include Combined Bisulphite Restriction Analysis and methylated DNA immunoprecipitation (MeDIP). Methodologies to analyze bisulfite-treated DNA are continuously being developed. To summarize these rapidly evolving methodologies, numerous review articles have been written. The methodologies can be generally divided into strategies based on methylation-specific PCR (MSP) (Figure 4), and strategies employing polymerase chain reaction (PCR) performed under non-methylation-specific conditions (Figure 3). Microarray-based methods use PCR based on non-methylation-specific conditions also.
=== Southern Route Partnership (SRP) === The SRP is a regional organisation, established through the UNODC’s Global Maritime Crime Programme within the Indian Ocean (GMCP IO). The concept of building the SRP was discussed during the UNODC meeting of the Heads of drug enforcement agencies from the Indian Ocean Region, in October 2016. The SRP involves states directly affected by the use of the southern route for smuggling, with anti-narcotics agencies from countries such as Kenya, South Africa, Sri Lanka, Tanzania, and the Seychelles becoming involved. The organisation aims to combat the smuggling of Afghan opiates through Pakistan, Iran, the Indian Ocean, and further on into East Africa. Partner agencies from a variety of countries and organisations outside of the region, such as the UK’s National Crime Agency, the Royal Canadian Mounted Police, and the Paris Pact Initiative have also been involved in SRP discussions. As of yet, there is little evidence available of how the SRP has been utilised, but it holds potential as a collaborative tool.
Sources: en.wikipedia.org
Hydrogen peroxide has a relatively elusive and highly unstable isomer called oxywater, also known as water oxide. Its chemical formula is H2OO and its systematic IUPAC name is oxidooxidanium. It is isoelectronic to fluoroamine and is a ylide. It rapidly decomposes to form hydrogen peroxide, the reaction mechanism for which is likely a 1,2-hydrogen shift.
Field and laboratory measurements have shown that reduced nitrogen-containing third-hand smoke compounds can partition from contaminated indoor surfaces into the gas phase and subsequently be taken up by aqueous aerosol particles, creating a particle-phase reservoir that allows THS components to persist and be redistributed within indoor air. Environmental tobacco smoke can oxidize with environmental nitrous acid to create carcinogenic (cancer-causing) tobacco-specific nitrosamines (TSNAs). One TSNA, called 4-(methylnitrosamino)-1-(3-pyridinyl)-1-butanone (also known as nicotine-derived nitrosamine ketone, or NNK), is a potent lung-specific carcinogen ubiquitous in tobacco smoke and smokers' homes, and has been detected on clothing fibers, dust, and in the air. Nitrosamines, along with other tobacco smoke chemicals that are deposited on surfaces or compounds that formed as a result of surface-phase reactions, can be a major source of toxicity, especially for infants. Infants can be particularly adversely affected given their frequent proximity to household surfaces and their propensity to ingest third-hand smoke residue from surfaces and dust. Review articles have suggested that third-hand smoke-type residues can arise not only from conventional tobacco smoking but also from emissions from e-cigarettes, cannabis and certain illicit substances, with the chemical composition, partitioning behaviour and routes of human exposure depending on the source material and indoor environment.
8 May Skipton Building Society becomes the first building society since the 2008 financial crisis to announce it will offer 100% mortgages, aimed at first-time buyers who cannot afford a deposit. Coronation of Charles III and Camilla: Official photographs of the King and Queen taken shortly after the Coronation ceremony are released. On the final day of celebrations, people are encouraged to get involved in the Big Help Out by joining volunteer projects across the UK. 9 May House of Commons Speaker Sir Lindsay Hoyle unveils two new stained glass windows at the Palace of Westminster. One featuring his new personal coat of arms, with a rugby league ball, bees and Lancashire roses. The other window celebrates Britain's Coat of Arms of all three Crown Dependencies and all sixteen British Overseas Territories. Hoyle said at the unveiling the windows were and "will forever be tangible reminders of the strong, close links between the United Kingdom, the overseas territories and the crown dependencies". A Freedom of Information request filed by The Guardian reveals that at least one baby has been born with the DNA of three people, with 0.1% of the third person's DNA used in an attempt to prevent children developing mitochondrial diseases. Addressing the issue of arrests made during the Coronation, Sir Mark Rowley, Commissioner of the Metropolitan Police, says it is unfortunate people were not allowed to protest, but that there was a credible threat to disrupt the ceremony.
This is a promising and newer microarray application for the diagnosis, study and treatment of complex diseases such as cancer. The technology merges laser capture microdissection (LCM) with micro array technology, to produce reverse-phase protein microarrays. In this type of microarrays, the whole collection of protein themselves are immobilized with the intent of capturing various stages of disease within an individual patient. When used with LCM, reverse phase arrays can monitor the fluctuating state of proteome among different cell population within a small area of human tissue. This is useful for profiling the status of cellular signaling molecules, among a cross-section of tissue that includes both normal and cancerous cells. This approach is useful in monitoring the status of key factors in normal prostate epithelium and invasive prostate cancer tissues. LCM then dissects these tissue and protein lysates were arrayed onto nitrocellulose slides, which were probed with specific antibodies. This method can track all kinds of molecular events and can compare diseased and healthy tissues within the same patient enabling the development of treatment strategies and diagnosis. The ability to acquire proteomics snapshots of neighboring cell populations, using reverse-phase microarrays in conjunction with LCM has a number of applications beyond the study of tumors. The approach can provide insights into normal physiology and pathology of all the tissues and is invaluable for characterizing developmental processes and anomalies.
Sources: en.wikipedia.org
No. It is a laboratory-made peptide, while the natural hormone is alpha-melanocyte-stimulating hormone, a longer peptide produced by the pituitary gland and by skin cells. Melanotan-2 mimics only a short active region of that hormone and contains non-natural residues such as D-phenylalanine.
No approved regulatory indication exists in major markets. An approval exists for a different peptide, afamelanotide, which is used for a rare photosensitivity disorder called erythropoietic protoporphyria. Melanotan-2 itself remains a research compound with no cleared clinical role.
Melanocortin-1 receptors on melanocytes are the receptor most closely linked to pigment production. The peptide is not selective, however, and also activates melanocortin-3, melanocortin-4, and melanocortin-5 receptors. That lack of selectivity is the usual explanation offered for both its range of observed effects and its off-target effects.
Solutions are best kept cold, protected from light, and buffered to a pH that limits hydrolysis. Dividing a stock into single-use aliquots avoids repeated freeze-thaw cycles, which measurably reduce the intact parent peak over time.