Everything below concerns alpha-MSH analog. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-12-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
Melanocortin receptors comprise five subtypes with distinct tissue distributions and functions. Melanotan-2 is described in the literature as a non-selective agonist that engages several of these subtypes, including MC1R, MC3R, MC4R, and MC5R. MC1R is the subtype most directly linked to melanin production in skin cells. Because the compound is not subtype-selective, its observed effects in experimental settings are generally attributed to activity across multiple receptor pathways rather than to a single target.
Melanotan-2 is a synthetic linear peptide built from seven amino acids arranged in a short chain. Its sequence is commonly written as Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH2, which includes a modified N-terminus and an amidated C-terminus. The molecule belongs to the melanocortin family and acts as a receptor agonist. Structural features such as the D-phenylalanine residue and the Nle substitution are associated with increased stability against enzymatic degradation relative to the natural parent peptide.
The compound emerged from research programs in the 1980s that examined analogues of alpha-melanocyte-stimulating hormone for pigmentation and photoprotection. Investigators modified the native sequence to extend activity duration and potency. A related analogue, afamelanotide, was developed within the same broad line of inquiry and eventually gained approval in certain jurisdictions for a rare light-sensitivity condition. Melanotan-2 itself did not progress through the same regulatory route and has no approved therapeutic indication.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Free base; salt forms differ |
| Molecular weight | Approximately 1024 g/mol | Calculated for the free base |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water and polar solvents | Poorly soluble in non-polar solvents |
| Typical storage | -20 degrees Celsius, dry, protected from light | Refers to the solid form |
Outside regulated medicine, melanotan II circulates through online vendors as a research chemical, often marketed for tanning. Products sold this way vary widely in purity, concentration, and labeling accuracy, and independent testing has documented discrepancies. Published reports describe both pigment effects and adverse reactions, including nausea, flushing, and darkening of existing moles. Long-term safety data are sparse, and no large controlled trial has established a risk profile. Questions about cumulative effects on melanocytes remain unresolved in the literature.
Melanotan II is a synthetic peptide analog modeled on alpha-melanocyte-stimulating hormone, a naturally occurring signaling peptide involved in pigmentation. Its structure is a cyclic heptapeptide containing two non-natural substitutions, norleucine at position four and D-phenylalanine at position seven. These modifications resist enzymatic breakdown and extend the molecule's activity relative to the native hormone. The compound binds melanocortin receptors and is studied mainly as a pharmacological tool rather than a therapeutic product. It has never received approval as a medicine in any major jurisdiction.
Two structural changes distinguish the synthetic peptide from the natural hormone. A norleucine residue replaces methionine at one position, and a D-configured phenylalanine replaces the natural L-form at another. Both substitutions slow enzymatic breakdown, which extends the molecule's persistence relative to the parent hormone. The lactam bridge further constrains the backbone into a stable conformation. These features are standard design strategies in peptide chemistry and are not unique to this compound; they appear across many research peptides built for improved stability.
The compound was developed in the late 1980s and early 1990s by academic researchers investigating melanocortin signaling and pigmentation. Early work explored whether synthetic analogs could reproduce effects of the natural hormone under controlled conditions. The molecule never advanced through the full regulatory pathway required for approval as a medicine. From the mid-2000s onward it appeared in unregulated consumer markets, often distributed through informal channels. That gap between research origins and commercial availability shapes how the compound is discussed today.
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.
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.
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.
Melanotan II is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its structure substitutes a lactam bridge between side chains to increase stability relative to the native hormone. The compound is also known by the shorthand MT-II and by several non-proprietary synonyms used in research catalogues. It is not an approved therapeutic product in any major jurisdiction; material sold under this name is typically offered as a laboratory reagent rather than as a medicine.
Barbara Walters Interview with General Schwarzkopf, Coalition commander in the Persian Gulf War (Video: ABC, 1991) Gulf War Discussion from the Dean Peter Krogh Foreign Affairs Digital Archives Historical Context from the Dean Peter Krogh Foreign Affairs Digital Archives CBC Digital Archives – The 1991 Gulf War Master Index of Desert Storm Oral History Interviews Archived 31 December 2010 at the Wayback Machine by the United States Army Center of Military History Bibliography of the Desert Shield and Desert Storm compiled by the United States Army Center of Military History (via Wayback Machine) Desert Shield/Desert Storm Photographs Archived 17 October 2015 at the Wayback Machine US Army Heritage and Education Center, Carlisle, Pennsylvania Persian Gulf War 20th Anniversary of Desert Storm in Photos Air Force and Air Defense of Iraq before the war (not translated) exact list of the technical details Liberating Kuwait United States Marine Corps Friendly-fire Incidents Archived 1 June 2013 at the Wayback Machine – www.gulflink.osd.mil Operations Desert Shield and Desert Storm: Valorous Unit Award Citations by the United States Army Center of Military History
== Host plants == The cabbage looper is a generalist insect that can reside and feed on over 160 host plants. The looper's variety of hosts is partially due to the ability of its salivary glands to differentially express based on the host. For example, cabbage and tomato plants use defensive strategies involving different compounds, and the cabbage looper can combat either by upregulating the appropriate genes. The gland's high responsiveness to the diet allows for considerable flexibility in host plants. The cabbage looper's preferred hosts are crucifers such as cabbage and broccoli, because it grows faster on these plants, possibly due to nutritional or chemical differences. Tobacco can also be a host for the cabbage looper. However, it is not preferred because gummosis, a gummy substance produced by some plants, and trichomes, hair-like appendages, harm early larvae survival. Older larvae are more resistant to these defenses. The number of caterpillars on a plant can depend on a plant's maturity. Cabbages that mature early are less attractive, whereas cabbages just beginning to head are the most attractive. Among crucifers, there generally seems to be no preference for one specific type of crucifer, like kale over cabbage or broccoli over brussels sprouts. The only apparent preference is for red cabbage – nearby double the number of caterpillars were present on the red cabbage compared to the green. This suggests that the number of caterpillars on a host plant has less to do with the species of host than with the host's height and foliage.
But Edith said she had agreed to marry Field only because she felt "on the shelf" and had begun to doubt that Tolkien still cared for her. She explained that, because of Tolkien's letter, everything had changed. On 8 January 1913 Tolkien travelled by train to Cheltenham and was met on the platform by Edith. The two took a walk into the countryside, sat under a railway viaduct, and talked. By the end of the day, Edith had agreed to accept Tolkien's proposal. She wrote to Field and returned her engagement ring. Field was "dreadfully upset at first", and the Field family was "insulted and angry". Upon learning of Edith's new plans, Jessop wrote to her guardian, "I have nothing to say against Tolkien, he is a cultured gentleman, but his prospects are poor in the extreme, and when he will be in a position to marry I cannot imagine. Had he adopted a profession it would have been different." Following their engagement, Edith reluctantly announced that she was converting to Catholicism at Tolkien's insistence. Jessop, "like many others of his age and class ... strongly anti-Catholic", was infuriated, and he ordered Edith to find other lodgings. Edith Bratt and Ronald Tolkien were formally engaged at Birmingham in January 1913, and married at St Mary Immaculate Catholic Church at Warwick, on 22 March 1916. In a 1941 letter to Michael, Tolkien expressed admiration for his wife's willingness to marry a man with no job, little money, and no prospects except the likelihood of being killed in the Great War.
Mexico has both public and private universities, with wide variation in terms of cost, academic performance, and organization. The most reputable and largest university, the National Autonomous University of Mexico (UNAM), is publicly funded and virtually free, while also independent from the government. Instituto Politécnico Nacional is a federally-administered public university. Several public state universities follow an autonomous model similar to UNAM, including Universidad de Guadalajara and Universidad Autónoma de Nuevo León. However, these state universities do not receive as much public funding, which means higher tuition fees.
Sources: en.wikipedia.org
The first use of small-molecule drugs to treat cancer was in the early 20th century, although the specific chemicals first used were not originally intended for that purpose. Mustard gas was used as a chemical warfare agent during World War I and was discovered to be a potent suppressor of hematopoiesis (blood production). A similar family of compounds known as nitrogen mustards were studied further during World War II at the Yale School of Medicine. It was reasoned that an agent that damaged the rapidly growing white blood cells might have a similar effect on cancer. Therefore, in December 1942, several people with advanced lymphomas (cancers of the lymphatic system and lymph nodes) were given the drug by vein, rather than by breathing the irritating gas. Their improvement, although temporary, was remarkable. Concurrently, during a military operation in World War II, following a German air raid on the Italian harbour of Bari, several hundred people were accidentally exposed to mustard gas, which had been transported there by the Allied forces to prepare for possible retaliation in the event of German use of chemical warfare. The survivors were later found to have very low white blood cell counts. After WWII was over and the reports declassified, the experiences converged and led researchers to look for other substances that might have similar effects against cancer. The first chemotherapy drug to be developed from this line of research was mustine.
=== The Manhattan Project === Nier returned to Minnesota in 1938 to be near his ageing parents. In 1940, on the request of Enrico Fermi, he and a few students, including Edward Ney, prepared a pure sample of uranium-235 using an early mass spectrograph designed by Nier, for John R. Dunning's team at Columbia University. On the day of its receipt (it was sent by US Postal Mail), Dunning's team was able to demonstrate that uranium-235 was the isotope responsible for nuclear fission, rather than the more abundant uranium-238. Confirmation of this suspected fact was a critical step in the development of the atomic bomb. From 1943 to 1945, Nier worked with Kellex Corporation in Manhattan, New York City on the design and development of efficient and effective mass spectrographs for use in the Manhattan Project to build the atomic bomb in World War II. During the war most of the spectrographs used for monitoring uranium separations were designed by Nier.
== Deterministic versus stochastic epidemic models == The deterministic models presented here are valid only in case of sufficiently large populations, and as such should be used cautiously. These models are only valid in the thermodynamic limit, where the population is effectively infinite. In stochastic models, the long-time endemic equilibrium derived above, does not hold, as there is a finite probability that the number of infected individuals drops below one in a system. In a true system then, the pathogen may not propagate, as no host will be infected. But, in deterministic mean-field models, the number of infected can take on real, namely, non-integer values of infected hosts, and the number of hosts in the model can be less than one, but more than zero, thereby allowing the pathogen in the model to propagate. The reliability of compartmental models is limited to compartmental applications. One of the possible extensions of mean-field models considers the spreading of epidemics on a network based on percolation theory concepts. Stochastic epidemic models have been studied on different networks and more recently applied to the COVID-19 pandemic.
That the notochord evolved de novo in chordates by combining development programs in new ways. That the notochord derives from a homologous muscular structure, the axochord, that was present in annelid-like ancestors of the chordates. Supported by gene expression patterns and identification of said muscular structures in various inveterates, but cannot fully rule out the possibility of homoplasy. Deciding between these two scenarios (or possibly another yet to be proposed) should be facilitated by much more thorough studies of gene regulatory networks in a wide spectrum of animals.
Menu items offered at Boston Market included various meats and sides, such as rotisserie chicken (whole, half, or quarter), apple pie, carved chicken sandwich, chicken salad sandwich, chicken noodle soup, chicken pot pie, cilantro lime rice, creamed spinach, Cobb salad, cornbread, garlic dill potatoes, mashed potatoes (with gravy), meatloaf and meatloaf sandwich, desserts (salted caramel lava cake, chocolate cake, or chocolate chip cookies), prime rib, ribs (beef, with sauce), steamed vegetables (e.g., broccoli), sweet potato casserole, and turkey (roasted). Many of the chicken items included rotisserie chicken, and the rotisserie oven was also used to cook other meats. Boston Market offered rotisserie nuggets for a time. Boston Market also had seasonal holiday menu and catering food packages, such as for Thanksgiving dinner (a traditional U.S. holiday meal), which included items such as a whole rotisserie turkey, mashed potatoes, gravy, vegetable stuffing, spinach-artichoke dip, cranberry walnut relish, dinner rolls, and pumpkin and apple pies. The Boston Market supermarket brand is produced by Bellisio Foods. As of 2024, it continues to produce items such as chicken pot pie bites, mashed potatoes, and chicken fajita rice bowls.
Sources: en.wikipedia.org
=== Inflammation === SP initiates expression of almost all known immunological chemical messengers (cytokines). Also, most of the cytokines, in turn, induce SP and the NK1 receptor. SP is particularly excitatory to cell growth and multiplication, via usual, as well as oncogenic drivers. SP is a trigger for nausea and emesis. Substance P and other sensory neuropeptides can be released from the peripheral terminals of sensory nerve fibers in the skin, muscle, and joints. It is proposed that this release is involved in neurogenic inflammation, which is a local inflammatory response to certain types of infection or injury.
=== Football clubs === In the 1960s, Inter Milan has its greatest period of success known as [La] Grande Inter ("Great Inter"), achieved when Helenio Herrera was their manager. He won seven trophies with the club. In 2004, Ferruccio Mazzola, Inter player during that period, accused him of distributing performance-enhancing drugs, including amphetamines, among the team players, especially the substitute players "who often served as guinea pigs for trying new pills and see if they worked." When he found out that some in the team were spitting them out, he dissolved them in coffee to make sure they were consumed, a practice known as Caffè di Herrera ("Herrera's Coffee"). In 2010, Inter sued Mazzola but lost the case, the court believed him. One of the reasons he spoke up were the serious medical conditions and/or deaths of some of his former members: Giuliano Taccola, then team's captain Armando Picchi (died aged 36 due to cancer), Marcello Giusti, Carlo Tagnin, Mauro Bicicli, Ferdinando Miniussi, Enea Masiero and Pino Longoni. He suspected the drugs to be the cause of their sufferings. in 2015, his brother Sandro, who denied everything at the beginning, admitted that the incidents happened. In the 1970s performance-enhancing drugs were used on a regular basis according to witnesses of that period, mostly in Ajax, Feyenoord and AZ Alkmaar during competitive matches, including the 1970 and 1972 Intercontinental Cups won by the first two cited clubs. Jan Peters recounted drug use before the big games. They seemed to work as he felt energy boosts and euphoria.
C12H22O11 + H2O → 2 C6H12O6 Heterolactic fermentation is in a sense intermediate between lactic acid fermentation and other types, e.g. alcoholic fermentation. Reasons to go further and convert lactic acid into something else include:
=== Others, associated with the city === Rex Cherryman (1896–1928), American actor, died here Jean-Paul Sartre (1905–1980), philosopher, taught at the Lycée François-Ier Patrick Demarchelier (1943–2022), fashion photographer, spent his childhood in Le Havre Christine Lagarde (born 1956), IMF managing director, grew up in Le Havre René Viénet (born 1944), sinologist Suzzane Fontaine (1894-1979), paternal grandmother of Pope Leo XIV
Sources: en.wikipedia.org
No. Melanotan-2 is manufactured synthetically. The naturally occurring peptide in the same family is alpha-melanocyte-stimulating hormone, which the body produces as part of normal endocrine and neural signalling.
Both are synthetic analogues derived from the same parent hormone. Reference descriptions usually characterise afamelanotide as more selective for the MC1R subtype, whereas melanotan-2 is reported to interact with a wider range of melanocortin receptors.
Early studies explored melanocortin signalling and pigmentation, which later led to informal use of the label tanning peptide. That label is not a regulatory category and does not imply approved status for any purpose.
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.