If you have been reading about afamelanotide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-12-09. Numbers and descriptions here follow the published literature rather than marketing material.
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.
=== 547th Grenadier Division === The division was created as the 547th Grenadier Division in Military District V (Stuttgart) as a so-called Sperrdivision ("blocking division") belonging to the 29th Aufstellungswelle ("Wave of formations"). It was scheduled to be formed on 11 July 1944, however, its actual formation took place on 27 July 1944. From August 1944, the division served with the 4th Army under Army Group Centre and fought in Lithuania. On 9 October 1944, the 547th Grenadier Division was redesignated as the 547th Volksgrenadier Division. The reorganization was intended to bring the unit up to the standard of a division belonging to the 32nd wave of formations.
== Entrepreneurship, Outreach, and Advocacy == Bhatia is a prolific inventor, holding more than 65 issued or pending patents for clinical and biotechnological applications of engineering principles over twenty years. Her entrepreneurial ventures include:
"You have no idea what the Tour de France is," Henri said. "It's a Calvary. Worse than that, because the road to the Cross has only 14 stations and ours has 15. We suffer from the start to the end. You want to know how we keep going? Here..." He pulled a phial from his bag. "That's cocaine, for our eyes. This is chloroform, for our gums." "This," Ville said, emptying his shoulder bag "is liniment to put warmth back into our knees." "And pills. Do you want to see pills? Have a look, here are the pills." Each pulled out three boxes. "The truth is," Francis said, "that we keep going on dynamite." Henri spoke of being as white as shrouds once the dirt of the day had been washed off, then of their bodies being drained by diarrhea, before continuing:
Kilishi – a version of biltong or jerky that originated in Hausaland, it is a delicacy made from cow, sheep or goat meat after the removal of bone. Kuivaliha – salted and dried meat, often reindeer meat, is a traditional food and a delicacy of northern Finland, prepared at springtime. Kulen – a kind of highly spiced, semi-dried, smoked, cured sausage from Croatia (Slavonia) and Serbia (Vojvodina). The meat undergoes fermentation-curing as well as the air-drying.
=== Cardiogenesis === Development of heart is involved in several rounds of EMT and MET. While development splanchnopleure undergo EMT and produce endothelial progenitors, these then form the endocardium through MET. Pericardium is formed by sinus venosus mesenchymal cells that undergo MET. Quite similar processes occur also while regeneration in the injured heart. Injured pericardium undergoes EMT and is transformed into adipocytes or myofibroblasts which induce arrhythmia and scars. MET than leads to the formation of vascular and epithelial progenitors that can differentiate into vasculogenic cells which lead to regeneration of heart injury.
Sources: en.wikipedia.org
== Human proteins containing laminin domains == Laminin domain I: all laminin alpha chains (LAMA1, LAMA2, LAMA3, LAMA4, LAMA5) Laminin domain II: all laminin alpha chains (LAMA1, LAMA2, LAMA3, LAMA4, LAMA5) Laminin B (domain IV): all laminin alpha chains (LAMA1, LAMA2, LAMA3, LAMA4, LAMA5), gamma chains (LAMC1, LAMC2, LAMC3), and perlecan (HSPG2) Laminin EGF-like (domains III and V): all laminin chains (LAMA1, LAMA2, LAMA3, LAMA4, LAMA5, LAMB1, LAMB2, LAMB3, LAMB4, LAMC1, LAMC2, LAMC3), attractins (ATRN, ATRNL1), cadherin EGF LAG seven-pass G-type receptors (CELSR1, CELSR2, CELSR3), cysteine-rich with EGF-like domain proteins (CRELD1, CRELD2), multiple EGF-like domain proteins (MEGF6, MEGF8, MEGF9, MEGF10, PEAR1), most netrins (NTN1, NTN3, NTN4, NTNG1, NTNG2), mucins 3A and 3B (MUC3A, MUC3B), class F scavenger receptors (SCARF1, SCARF2), stabilins (STAB1, STAB2), agrin (AGRIN), angiopoietin-1 receptor (TEK), perlecan (HSPG2), tenascin N (TNN), and usherin (USH2A).
isoelectronicity The phenomenon of two or more chemical species (atoms, molecules, ions, etc.) being composed of different elements but having the same number of valence electrons and the same structural arrangement (i.e. the same number of atoms with the same connectivity). Isoelectronic species typically show useful consistency and predictability in their chemical properties.
Efforts toward reconstruction in the secessionist South had begun as early as 1862, but it was only after President Lincoln's assassination that the three Reconstruction Amendments to the Constitution were ratified to protect civil rights. The amendments codified nationally the abolition of slavery and involuntary servitude except as punishment for crimes, promised equal protection under the law for all persons, and prohibited denial or abridgment of voting rights on the basis of race, color, or previous enslavement. As a result, African Americans took an active political role in ex-Confederate states in the decade following the Civil War. The former Confederate states were readmitted to the Union, beginning with Tennessee in 1866 and ending with Georgia in 1870. National infrastructure, including transcontinental telegraph and railroads, spurred growth in the American frontier. This was accelerated by the Homestead Acts, through which nearly 10 percent of the total land area of the United States was given away free to some 1.6 million homesteaders. From 1865 through 1917, an unprecedented stream of immigrants arrived in the United States, including 24.4 million from Europe. Most came through the Port of New York, as New York City and other major cities on the East Coast became home to large Jewish, Irish, and Italian populations. Many Northern Europeans as well as significant numbers of Germans and other Central Europeans moved to the Midwest. At the same time, about one million French Canadians migrated from Quebec to New England.
As demonstrated in the figure, the enzyme groups cellulase, PETase, and keratinase are used within the closed recycling loop to break down old textiles such as polyester and nylon into amino acids, glucose, or synthetic monomer building blocks. These monomers then undergo chemical polymerization and are combined to create high quality polylactic acid (PLA), polyhydroxyalkanoates (PHAs), silk, and bacterial cellulose polymers. Afterwards, these synthesized polymers are used to create man made, biodegradable fibers, which are then used to make new, biodegradable textiles. These textiles are used until their become worn down and are depolymerized to continue the closed recycling loop.
Sources: en.wikipedia.org
Cercopagis pengoi, or the fishhook waterflea, is a species of planktonic cladoceran crustaceans that is native in the brackish fringes of the Black Sea and the Caspian Sea. In recent decades it has spread as an invasive species to some freshwater waterways and reservoirs of Eastern Europe and to the brackish Baltic Sea. Further it was introduced in ballast water to the Great Lakes of North America and a number of adjacent lakes, and has become a pest classified among the 100 worst invasive species of the world. Cercopagis pengoi is a predatory cladoceran and thus a competitor to other planktivorous invertebrates and smaller fishes. On the other hand, it has provided a new food source for planktivorous fishes. It is also a nuisance to fisheries as it tends to clog nets and fishing gear.
Cytotoxic T cells (also known as Tc, killer T cell, or cytotoxic T-lymphocyte (CTL)) express CD8 co-receptors and are a population of T cells that are specialized for inducing programmed cell death of other cells. Cytotoxic T cells regularly patrol all body cells to maintain the organismal homeostasis. Whenever they encounter signs of disease, caused for example by the presence of viruses or intracellular bacteria or a transformed tumor cell, they initiate processes to destroy the potentially harmful cell. All nucleated cells in the body (along with platelets) display class I major histocompatibility complex (MHC-I molecules). Antigens generated endogenously within these cells are bound to MHC-I molecules and presented on the cell surface. This antigen presentation pathway enables the immune system to detect transformed or infected cells displaying peptides from modified-self (mutated) or foreign proteins. In the presentation process, these proteins are mainly degraded into small peptides by cytosolic proteases in the proteasome, but there are also other cytoplasmic proteolytic pathways. Then, peptides are distributed to the endoplasmic reticulum (ER) via the action of heat shock proteins and the transporter associated with antigen processing (TAP) which translocates the cytosolic peptides into the ER lumen in an ATP-dependent transport mechanism. There are several ER chaperones involved in MHC-I assembly, such as calnexin, calreticulin, Erp57, protein disulfide isomerase (PDI), and tapasin.
Each lung is enclosed within a pleural sac of two pleurae which allows the inner and outer walls to slide over each other whilst breathing takes place, without much friction. The inner visceral pleura divides each lung as fissures into sections called lobes. The right lung has three lobes and the left has two. The lobes are further divided into bronchopulmonary segments and lobules. The lungs have a unique blood supply, receiving deoxygenated blood sent from the heart to receive oxygen (the pulmonary circulation) and a separate supply of oxygenated blood (the bronchial circulation). The tissue of the lungs can be affected by several respiratory diseases including pneumonia and lung cancer. Chronic diseases such as chronic obstructive pulmonary disease and emphysema can be related to smoking or exposure to harmful substances. Diseases such as bronchitis can also affect the respiratory tract. Medical terms related to the lung often begin with pulmo-, from the Latin pulmonarius (of the lungs) as in pulmonology, or with pneumo- (from Greek πνεύμων "lung") as in pneumonia. In embryonic development, the lungs begin to develop as an outpouching of the foregut, a tube which goes on to form the upper part of the digestive system. When the lungs are formed the fetus is held in the fluid-filled amniotic sac and so they do not function to breathe. Blood is also diverted from the lungs through the ductus arteriosus. At birth however, air begins to pass through the lungs, and the diversionary duct closes so that the lungs can begin to respire.
British William Prout first proposed ordering all the elements by their atomic weight as all atoms had a weight that was an exact multiple of the atomic weight of hydrogen. J.A.R. Newlands devised an early table of elements, which was then developed into the modern periodic table of elements in the 1860s by Dmitri Mendeleev and independently by several other scientists including Julius Lothar Meyer. The inert gases, later called the noble gases were discovered by William Ramsay in collaboration with Lord Rayleigh at the end of the century, thereby filling in the basic structure of the table. Organic chemistry was developed by Justus von Liebig and others, following Friedrich Wöhler's synthesis of urea. Other crucial 19th century advances were; an understanding of valence bonding (Edward Frankland in 1852) and the application of thermodynamics to chemistry (J. W. Gibbs and Svante Arrhenius in the 1870s).
In 2020, Chen Xiaojiang was appointed as head of the National Ethnic Affairs Commission, the first Han Chinese head of the body since 1954. On 24 June 2022, Pan Yue, another Han Chinese, became the head of the commission, with him reportedly holding assimilationist policies toward ethnic minorities. Xi outlined his official views relations between the majority Han Chinese and ethnic minorities by saying "[n]either Han chauvinism nor local ethnic chauvinism is conducive to the development of a community for the Chinese nation." Xi's policies toward ethnic minorities were codified in the Law on Promoting Ethnic Unity and Progress in 2026.
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.