alpha-MSH analogue is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2025-08-26. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Analogue of alpha-melanocyte-stimulating hormone |
| Common synonyms | MT-II; melanotan 2 | No internationally accepted non-proprietary name |
| Typical presentation | Lyophilised powder in a sealed vial | Often supplied alongside a separate diluent |
| Regulatory status | Unapproved therapeutic substance | Customs seizure reported in several jurisdictions |
| Reported route in use | Subcutaneous injection | Self-administered outside clinical settings |
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence incorporates a lactam bridge that constrains the peptide into a ring, which increases resistance to enzymatic breakdown relative to the natural hormone. Researchers at the University of Arizona synthesised the compound in the late 1980s and early 1990s while studying pigmentation pathways. It has never received marketing approval from any national medicines regulator. In the scientific literature it is usually described as a laboratory research reagent rather than a therapeutic product.
The peptide acts as a non-selective agonist at melanocortin receptors, showing affinity for MC1R, MC3R, MC4R and MC5R. Activation of MC1R on melanocytes drives the conversion of tyrosine into melanin and shifts production toward the darker eumelanin form. MC4R signalling in the central nervous system is linked to appetite and energy balance, which helps explain why reduced food intake appeared in early human studies. Effects on MC4R and on vascular tone also account for the erectile responses recorded as unexpected findings in those same trials.
Receptor binding at MC1R on melanocytes raises intracellular cyclic AMP and increases expression of tyrosinase and related enzymes. The downstream result is greater synthesis of eumelanin, the dark pigment, without ultraviolet exposure acting as the trigger. The compound is not selective, however, and also engages MC3R, MC4R and MC5R, which are expressed in the central nervous system and elsewhere. That lack of selectivity is the explanation usually offered for effects reported outside pigmentation, including appetite suppression and nausea. Selectivity remains a central theme in comparative studies of related peptides.
Human data remain limited and mostly short-term. Reports describe small trials and observational accounts rather than large controlled studies, so questions about dose-response relationships and long-term effects on melanocytes stay open. Whether repeated exposure alters naevus behaviour is not settled in the published record. Researchers also note that self-administered use outside clinical settings makes actual exposure difficult to quantify. Statements about efficacy and safety should therefore be read as preliminary rather than established.
In February 2010, the FDA's associate director of drug safety, recommended rosiglitazone be taken off the market. In June 2010, they published a retrospective study comparing roziglitazone to pioglitazone, the other thiazolidinedione marketed in the United States and concluded rosiglitazone was associated with "an increased risk of stroke, heart failure, and all-cause mortality and an increased risk of the composite of AMI, stroke, heart failure, or all-cause mortality in patients 65 years or older". The number needed to harm with roziglitazone was sixty. Graham argued rosiglitazone caused 500 more heart attacks and 300 more heart failures than its main competitor. Two meta analyses released in 2010, one incorporating 56 trials and a second incorporating 164 trials reached conflicting conclusions. Nissen et al. found again an increased risk for heart infarction against control, but no increased risk for cardiovascular death. Mannucci et al. found no statistically significant increase in cardiac events but a significant increase in heart failure. A 2011 drug class review found an increased risk of cardiovascular adverse events. A meta-analysis of 16 observational studies released in March, 2011, compared rosiglitazone to pioglitazone, finding support for greater cardiovascular safety for pioglitazone. The meta-analysis involved 810 000 patients taking rosiglitazone or pioglitazone. The study suggests 170 excess myocardial infarctions, 649 excess cases of heart failure, and 431 excess deaths for every 100 000 patients who receive rosiglitazone rather than pioglitazone.
It was around the same time, with the work of Jean-Baptiste Bécœur in particular, that taxidermy became a more serious practice. Louis Dufresne, a taxidermist at the Muséum National d'Histoire Naturelle in France, rediscovered Bécœur's taxidermy process using arsenical soap and made it known through an article in the Nouveau dictionnaire d'histoire naturelle (1803–1804). This technique enabled the museum to build an immense collection of taxidermy birds. In the 19th century, some hunters took their trophies to upholstery shops, where the upholsterers would sew up the animal skins and stuff them with rags and cotton. The term "stuffing" or a "stuffed animal" evolved from this crude form of taxidermy. Professional taxidermists prefer the term "mounting" to "stuffing". More sophisticated cotton-wrapped wire bodies supporting sewn-on cured skins soon followed. Dufresne's methods spread to England in the early 19th century, where updated and non-toxic methods of preservation were developed by some of the leading naturalists of the day, including Rowland Ward and Montague Brown. Ward established one of the earliest taxidermy firms, Rowland Ward Ltd. of Piccadilly. However, the art of taxidermy remained relatively undeveloped, and the specimens remained stiff and unconvincing. Between 1887 and 1894, many naturalist scientists from all over the world went to Costa Rica to research its bird wildlife. At that time, Costa Rica had unique bird species not found in other parts of the world.
Multiplying by the molar mass constant ensures that the calculation is dimensionally correct: relative atomic masses and standard atomic weights are dimensionless quantities (i.e., pure numbers), whereas molar masses have units (in this case, grams per mole). Some elements are usually encountered as molecules, e.g. hydrogen (H2), nitrogen (N2), oxygen (O2), sulfur (S8), chlorine (Cl2). The molar mass of molecules of these elements is the molar mass of the atoms multiplied by the number of atoms in each molecule:
Sources: en.wikipedia.org
=== Mechanism of action === Ezetimibe inhibits the absorption of cholesterol from the small intestine and decreases the amount of cholesterol normally available to liver cells. The lower levels of cholesterol in the liver cells lead them to absorb more cholesterol from circulation thus lowering the levels of circulating cholesterol. It blocks the critical mediator of cholesterol absorption, the Niemann-Pick C1-like 1 (NPC1L1) protein on the gastrointestinal tract epithelial cells, as well as in hepatocytes; it blocks aminopeptidase N and interrupts a caveolin 1–annexin A2 complex involved in trafficking cholesterol.
Caspar Bartholin (whom Bartholin's glands are named after), a 17th-century Danish anatomist, dismissed Colombo's and Falloppio's claims that they discovered the clitoris, arguing that the clitoris had been widely known to medical science since the second century. Although 17th-century midwives recommended to men and women that women should aspire to achieve orgasms to help them get pregnant for general health and well-being and to keep their relationships healthy, debate about the importance of the clitoris persisted, notably in the work of Regnier de Graaf in the 17th century and Georg Ludwig Kobelt in the 19th. Like Falloppio and Bartholin, de Graaf criticized Colombo's claim of having discovered the clitoris; his work appears to have provided the first comprehensive account of clitoral anatomy. "We are extremely surprised that some anatomists make no more mention of this part than if it did not exist at all in the universe of nature", he stated. "In every cadaver, we have so far dissected we have found it quite perceptible to sight and touch". De Graaf stressed the need to distinguish nympha from clitoris, choosing to "always give [the clitoris] the name clitoris" to avoid confusion; this resulted in the frequent use of the correct name for the organ among anatomists, but considering that nympha was also varied in its use and eventually became the term specific to the labia minora, more confusion ensued.
For example, phenanthrene has two Clar structures: one with just one aromatic sextet (the middle ring), and the other with two (the first and third rings). The latter case is therefore the more characteristic electronic nature of the two. Therefore, in this molecule the outer rings have greater aromatic character whereas the central ring is less aromatic and therefore more reactive. In contrast, in anthracene the resonance structures have one sextet each, which can be at any of the three rings, and the aromaticity spreads out more evenly across the whole molecule. This difference in number of sextets is reflected in the differing ultraviolet–visible spectra of these two isomers, as higher Clar pi-sextets are associated with larger HOMO–LUMO gaps; the highest-wavelength absorbance of phenanthrene is at 293 nm, while anthracene is at 374 nm. Three Clar structures with two sextets each are present in the four-ring chrysene structure: one having sextets in the first and third rings, one in the second and fourth rings, and one in the first and fourth rings. Superposition of these structures reveals that the aromaticity in the outer rings is greater (each has a sextet in two of the three Clar structures) compared to the inner rings (each has a sextet in only one of the three).
Sources: en.wikipedia.org
Beyond these cinema-specific efforts, the FBI played a surprisingly large role in the production of movies, instituting a triangular-shaped film strategy: FBI set up a surveillance operation in Hollywood, made efforts to pinpoint and blacklist Communists, secretly laundered intelligence through HUAC, and further helped in producing movies that "fostered [the FBI] image as the protector of the American people." The FBI additionally endorsed films, including Oscar winner The Hoaxters. In the 1960s, Hollywood began using spy films to create the enemy through film. Previously, the influence of the Cold War could be seen in many, if not all, genres of American film. By the 1960s, spy films were effectively a "weapon of confrontation between the two world systems." Both sides heightened paranoia and created a sense of constant unease in viewers through the increased production of spy films. Film depicted the enemy in a way that caused both sides to increase general suspicion of foreign and domestic threat.
Candidates were asked to give yes or no responses to whether or not January 6 was an "inside job" and whether or not the 2020 election was "stolen". Those that did not say yes to both answers were not hired.
== Awards == In 1980, she was the recipient of a Guggenheim Fellowship. Other honors include the Award for Distinguished Contributions to Psychology in the Public Interest of the American Psychological Association, the NYU Alumni Achievement Award, the Liberty Science Center Genius Award, the Distinguished Contributions of Basic Science to Applied Psychology award from the American Association of Applied and Preventive Psychology, the James McKeen Cattel Award, and the Gordon Allport Intergroup Relations Prize.
During the mid-19th century, attempts were made to ship agricultural products by rail. As early as 1842, the Western Railroad of Massachusetts was reported in the June 15 edition of the Boston Traveler to be experimenting with innovative freight car designs capable of carrying all types of perishable goods without spoilage. The first refrigerated boxcar entered service in June 1851, on the Northern Railroad (New York) (or NRNY, which later became part of the Rutland Railroad). This "icebox on wheels" was a limited success since it was only functional in cold weather. That same year, the Ogdensburg and Lake Champlain Railroad (O&LC) began shipping butter to Boston in purpose-built freight cars, using ice for cooling.
Sources: en.wikipedia.org
No. No major regulatory agency has granted a marketing authorisation for melanotan II as a medicine. Products sold under this name are generally presented as laboratory reagents and are not subject to the batch-release testing applied to approved drugs.
It was developed in the 1980s by researchers investigating analogues of alpha-melanocyte-stimulating hormone for pigmentation and related endpoints. Early work included small human studies during the 1990s. Development did not progress to licensing, and the compound remained a research and grey-market item.
Peptides are prone to truncation, oxidation and aggregation during synthesis and handling. Without independent testing, a buyer cannot confirm the identity or the content of a vial. Analytical surveys of unapproved peptide products have repeatedly found discrepancies between label claims and measured composition.
It is a synthetic cyclic heptapeptide and an analogue of alpha-melanocyte-stimulating hormone. The molecule is produced by chemical synthesis rather than extracted from a biological source.