afamelanotide raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-02-22. Anything still debated is marked as such rather than presented as settled.
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.
Regulatory status varies by jurisdiction, and the substance is frequently described as unapproved for therapeutic use. Some authorities classify it alongside prescription-only medicines or controlled categories, while others address it through general consumer protection rules. Analytical surveys have reported mismatches between label claims and measured content in products sold online, although the scope of such testing is limited. Whether these discrepancies are widespread remains an open question. Discussion in the literature therefore tends to combine chemistry, supply-chain observation and policy analysis.
The material is commonly handled as a lyophilized powder in sealed vials. The solid dissolves readily in water and in polar organic solvents, producing a clear solution after reconstitution. Light, heat and repeated freeze-thaw cycles are the concerns most often raised in handling guidance, because peptide bonds and the constrained ring can degrade. Working solutions are generally prepared fresh, and material left in solution is treated as less stable than the dry form. These properties shape how laboratories store and aliquot reference material.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Retention time supports identity, while the mass spectrum confirms the molecular weight of the intact peptide. Purity is frequently reported as a percentage of total peak area, a figure that depends on the wavelength, column and gradient used. Impurity profiling may also look for truncated sequences, oxidised forms and residual counterions. Amino acid analysis and peptide mapping provide orthogonal confirmation when required.
| 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 |
Activity is attributed to agonism at melanocortin receptors, particularly MC1R and MC4R. Activation of MC1R on melanocytes increases melanin synthesis, which underlies the reported tanning effect. MC4R engagement in the central nervous system is linked to appetite suppression and to effects on sexual arousal reported in early clinical studies. Those studies were small and were not designed to establish efficacy or long-term safety. Receptor selectivity among the melanocortin subtypes is not absolute, which complicates attribution of any effect to a single pathway.
Regulatory treatment varies between countries. Several national medicines agencies have classified the peptide as unapproved, and customs authorities in some jurisdictions seize shipments on that basis. A few jurisdictions channel supply through prescription-only frameworks that do not list the substance by name. Because the material circulates mainly through online vendors, composition and purity are rarely verified before sale. Surveys of unapproved peptide products have reported labels that did not match measured content in a substantial fraction of samples.
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.
By the mid-2000s, Liebling had nearly disappeared from public life. He spent his days isolated in his parents' basement, trapped in a relentless cycle of addiction and self-destructive behavior. The toll of decades of substance abuse was evident in his skeletal frame, which was covered in sores and barely functioning, leading many to believe he was beyond redemption. This chapter of his life, which took an unexpected turn, became the subject of the documentary Last Days Here (2011), directed by Don Argott and Demian Fenton. Filmed over four years, the documentary follows Liebling, who is in his 50s and living in the basement of his parents' house in Alexandria, Virginia, as he battles severe drug addiction. His friend, manager, and longtime Pentagram fan Sean "Pellet" Pelletier took it upon himself to pull Liebling out of the abyss and get him back to music and a healthier life. Alongside Pelletier, the film features interviews with former Pentagram members, friends, Liebling's parents, and his then-girlfriend, Hallie. The documentary ends on a hopeful note; by 2010, Pentagram had returned to the stage, and Liebling was sober, married to Hallie, and expecting their first child. When Argott and Fenton first met Liebling, they had little hope that his story would lead anywhere. "Bobby was in such bad shape when Pellet introduced us to him that we didn't think his story would go anywhere. It really seemed like he was going to smoke himself to death in his parents' basement, something we weren't interested in documenting," Fenton recalled.
=== New East German immigration policy === On 19 October, Krenz asked Gerhard Lauter to draft a new travel policy. Lauter was a former People's Police officer. After rising rapidly through the ranks he had recently been promoted to a position with the Interior Ministry ("Home Office" / "Department of the Interior") as head of the department responsible for issuing passports and the registration of citizens. On 8 November, the East German Politburo enacted a portion of the draft travel regulations addressing permanent emigration immediately. Initially, the Politburo planned to create a special border crossing near Schirnding specifically for this emigration. However, Interior Ministry officials and Stasi bureaucrats charged with drafting the new text concluded the proposal was not feasible, and instead crafted new text relating to both emigration and temporary travel. The revised text stipulated East German citizens could apply for permission to travel abroad, without having to meet the previous requirements for those trips. To ease the difficulties, the Krenz-led Politburo decided on 9 November refugees could exit directly through crossing points between East Germany and West Germany, including between East and West Berlin. Later the same day, the ministerial administration modified the proposal to include private, round-trip, travel. The new regulations would take effect the next day.
=== August === August 1 A mass shooting occurs at an In-N-Out in Twin Falls, Idaho, leaving four dead (including the perpetrator) and seven injured. The Marine Corps reports that an F-35B stealth warplane crashed in California, but the pilot bailed safely. Cyberwarfare during the Iran war: The New York Times reports, citing state and local officials, that evidence leads to Iran in a series of cyberattacks against water systems in at least seven US states, with Michigan being the second state to report the attacks publicly. August 2 – 2026 Iran war: Following Qatari diplomatic efforts to avert planned strikes and reopen the Strait of Hormuz, and concerns raised by Saudi Crown Prince Mohammed bin Salman over the proposed operation, Trump says that the United States and Israel have called off an attack on Iran after Tehran requested additional time to reach an agreement. Trump nevertheless stresses that the United States remains prepared to launch a large-scale bombing campaign against Iran. August 3 – The Supreme Court declines to halt a $655 million judgement against Palestinian authorities for attacks that killed and maimed Americans in Israel from 2002 to 2004. August 4 – The Women's National Basketball Association (WNBA) announces that the expansion team in Cleveland, Ohio, will be called the Sirens. The organization will debut in 2028. August 5 Drive-thru chain Salad and Go files for Chapter 11 bankruptcy and closes all 70 of its locations across Arizona and Nevada, citing the 2026 cyclosporiasis outbreak as part of the reason for declining business.
Enzymes incur catalysis by binding more strongly to transition states than substrates and products. At the catalytic binding site, several different interactions may act upon the substrate. These range from electric catalysis, acid and base catalysis, covalent catalysis, and metal ion catalysis. These interactions decrease the activation energy of a chemical reaction by providing favorable interactions to stabilize the high energy molecule. Enzyme binding allows for closer proximity and exclusion of substances irrelevant to the reaction. Side reactions are also discouraged by this specific binding. Types of enzymes that can perform these actions include oxidoreductases, transferases, hydrolases, lyases, isomerases, and ligases. For instance, the transferase hexokinase catalyzes the phosphorylation of glucose to make glucose-6-phosphate. Active site residues of hexokinase allow for stabilization of the glucose molecule in the active site and spur the onset of an alternative pathway of favorable interactions, decreasing the activation energy.
The raw sequencing data is then processed through bioinformatics (e.g., the GemCode analysis software developed by 10x Genomics) to remove low-quality reads and to assign reads to their respective barcodes. Reads can be aligned to a reference genome or assembled de novo to generate long-range contigs. The read alignment step is important for determining the order and orientation of the long DNA fragments, and for identifying genomic variations, such as insertions or deletions.
Sources: en.wikipedia.org
‰ Peedee Belemnite ("PDB"), a fossil belemnite from the eponym Late Cretaceous geological formation in North and South Carolina (USA), was the original reference standard used for standardizing carbon isotope ratio values. Due to the depletion of the original PDB, an artificial "Vienna PDB" standard, or "VPDB", is generally used today.
Cannabidiol has been used by professional and amateur athletes across disciplines and countries, with the World Anti-Doping Agency removing CBD from its banned substances list. The United States Anti-Doping Agency and United Kingdom-Anti-Doping Agency do not have anti-CBD policies, with the latter stating that, "CBD is not currently listed on the World Anti-Doping Agency Prohibited List. As a result, it is permitted to use in sport, though the intended benefits are unclear and not backed by clinical evidence. All other cannabinoids (including but not limited to cannabis, hashish, marijuana, and THC) are prohibited in-competition. The intention of the regulations is to prohibit cannabinoids that activate the same receptors in the brain as activated by THC." In 2019, the cannabis manufacturer Canopy Growth acquired majority ownership of BioSteel Sports Nutrition, which is developing CBD products under endorsement by numerous professional athletes. The National Hockey League Alumni Association began a project with Canopy Growth to determine if CBD or other cannabis products might improve neurological symptoms and quality of life in head-injured players. Some sports leagues have announced sponsorships with CBD companies, such as Major League Baseball (Charlotte's Web) and Ultimate Fighting Championship (Love Hemp). Numerous professional athletes use CBD, primarily for treating pain.
==== Education ==== In February 2022, before assuming the presidency, Peña emphasized the need to turn government plans into state policies, especially in education and health. He proposed beginning a process of educational transformation in Paraguay, focusing on improving human capital as an engine of progress. Carlos Giménez, Paraguay's minister of agriculture and livestock, stated in late February 2024 his opposition to the admission of people with "homosexual tendencies" to agricultural schools. He later apologized for "the interpretation of his statements". Santiago Peña regretted the remarks but kept him in office, without imposing sanctions. In April 2024, Peña enacted the "Zero Hunger in Schools" law, passed by the Congress, a program that seeks to guarantee food for students in the country's public educational institutions. According to the newspaper ABC Color, the program excluded hundreds of children from special schools and inclusion support centers, leaving them without food. The Ministry of Education and Sciences (MEC) acknowledged the situation and proposed reviewing and correcting the scope of the program. During the start of the school year in February 2025, Peña acknowledged deficiencies in school infrastructure, committing himself to improving the physical conditions of educational institutions to facilitate an adequate learning environment.
parvulus, has been found in wines that have not gone through MLF (meaning malic acid is still present in the wine), but has still had its bouquet altered in a way that enologist have described as "not spoiled" or flaw. Other studies have isolated P. parvulus from wines that have gone through malolactic fermentation without the development of off odors or wine faults.
Sources: en.wikipedia.org
=== Prop Hunt === The game mode Prop Hunt was created by Andrew "AMT" Theis and popularised through Garry's Mod. In Prop Hunt, the players on one team are disguised as props and set to hide on the game map while the other team seeks after them. Game modes based on Prop Hunt were later included with games like Call of Duty: Modern Warfare Remastered, Call of Duty: Black Ops III, Fortnite Battle Royale, and Genshin Impact. Players recreated it in others, such as Rocket League and Fortnite Creative.
Monosubstituted products are formed by reacting a large excess of amine with ethylene oxide in presence of water and at a temperature below 100 °C (212 °F). Disubstituted products are obtained with a small excess of ethylene oxide, at a temperature of 120–140 °C (250–280 °F) and a pressure of 0.3–0.5 MPa (45–75 psi).
Will Self, novelist (Jewish mother); son of Peter Self, and grandson of Sir Albert Henry Self Charles Gabriel Seligman FRS FRAI (né Seligmann; 24 December 1873 – 19 September 1940) was author, scholar, academic, physician and ethnologist; main ethnographic work described culture of Vedda people of Sri Lanka and Shilluk people of Sudan; was professor at London School of Economics; influential as the teacher of Bronisław Malinowski, E. E. Evans-Pritchard, and Meyer Fortes; was proponent of the Hamitic hypothesis, according to which some civilisations of Africa were thought to have been founded by Caucasoid Hamitic peoples. His work in the 1920s and 1930s is now seen as "white supremacist". Nicholas Serota (born 27 April 1946), author, art historian and curator; served as Director of the Tate from 1988 to 2017; currently Chair of Arts Council England; was previously Director of The Museum of Modern Art, Oxford, and Director of the Whitechapel Gallery, before becoming Director of the Tate; was also Chairman of the Turner Prize jury. Malcolm Shaw (academic) KC (born 1947), British legal academic, author, editor and lawyer; studied at University of Liverpool (LLB), Hebrew University of Jerusalem (LLM) and Keele University (PhD); was the Sir Robert Jennings Professor of International Law at the University of Leicester and taught international law, human rights and equity and trusts; appointed as Senior Fellow at Lauterpacht Centre for International Law at University of Cambridge; Trustee of the British Institute of International and Comparative Law.
== Scientific background == Platelet-derived growth factor (PDGF) is a signalling protein involved in wound healing, tissue repair, and angiogenesis. Research has established that PDGF stimulates chemotaxis and proliferation in monocytes, macrophages and fibroblasts, playing a key regulatory role in the tissue repair cascade. Studies have further shown that exogenous recombinant PDGF-BB significantly accelerates wound closure in both incisional and excisional wound models. Other growth factors, including transforming growth factor-β, have also been studied in experimental wound-healing models. The only PDGF-based drug currently approved by a major regulatory authority is becaplermin, sold under the brand name Regranex, a recombinant human PDGF-BB gel approved by the U.S. Food and Drug Administration (FDA) in 1997 for the treatment of diabetic neuropathic foot ulcers. As of the date of this article, no PDGF drug has been approved for commercial sale in China.
Gotcha! (1985 film) is a film about a college student named Jonathan (Anthony Edwards) who plays a game called Gotcha in which he hunts and is hunted by other students with paint guns on campus. Jonathan goes to France on vacation, meets a beautiful woman named Sasha (Linda Fiorentino), travels with her to East Germany, and unknowingly becomes involved in the spy game between the US and USSR. The Kremlin Letter is a 1970 American neo-noir espionage thriller set in the winter of 1969–1970, at the height of US-Soviet tensions. No Way Out a 1987 film about a spy myth that is created to cover up the killing of the mistress of a high American official.
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.
The dry powder is more stable during transport and storage than a solution. It also allows a known amount of material to be reconstituted at a chosen concentration.