A practical reference on alpha-MSH analogue: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-06-14. Anything still debated is marked as such rather than presented as settled.
Melanotan-2 is frequently confused with afamelanotide, a linear analogue authorised in the European Union for erythropoietic protoporphyria. The two compounds differ in chain length, ring structure and receptor selectivity, so findings for one cannot be transferred directly to the other. Published controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports. Questions about effect size, dose-response behaviour and long-term safety therefore remain unresolved.
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 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.
No regulatory authority has approved melanotan-2 for human use, and several countries classify it as a prescription-only or controlled substance, which restricts lawful supply. Material sold online is generally labelled as a research chemical and is not required to meet pharmaceutical standards of identity or purity. Published human data consist mainly of small uncontrolled studies, case reports and adverse-event notifications, so the evidence base is descriptive rather than confirmatory. Whether repeated melanocyte stimulation alters long-term naevus behaviour remains an open question that no completed trial has resolved.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Alpha-MSH analogue with a lactam ring |
| Molecular formula | C50H69N15O9 | Commonly cited value for the neutral peptide |
| Molecular weight | 1024.18 g/mol | Calculated for the free molecule |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water, DMSO and ethanol | Dissolution in pure water is often slow |
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.
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.
Board of directors. Jo Coburn (born 12 November 1967); broadcaster and journalist with BBC News, married to former Downing Street head of strategic communications Mark Flanagan; regular presenter of Politics Live (and formerly also Sunday Politics along with Andrew Neil) and previously had special responsibility for BBC Breakfast; former BBC political correspondent for London, who covered the 2000 London Mayoral election; occasional relief presenter on the BBC News Channel. She has presented on BBC Radio 4 in the past and also has guested on the weekend current affairs programme The World This Weekend as well as reviewing the Sunday newspapers on The Andrew Marr Show. Benjamin Cohen (journalist) (born 14 August 1982), web developer, entrepreneur and online publisher; founder of LGBT news site PinkNews;from 2006 until 2012 was technology correspondent for Channel 4 News. He is the Chief Executive of PinkNews, and regularly writes for the London Evening Standard. Dave Cohen (writer); writer for television and radio as well as contributing columns to NME, Chortle and The Huffington Post.; has written for BBC Radio 4 including The Best of British, Dead Ringers which won a Sony Gold Award 2001, The Sunday Format, The News Quiz and 15 Minute Musical which he was also a co-creator and won the 2009 Writer's Guild Best Radio Comedy Show, to name a few. He also wrote for BBC Radio 5's The Treatment and They Came From Nowhere; has written for Rory Bremner Show, Spitting Image, Eleven O'Clock Show, Not Going Out and My Family.
=== Pilonidal sinus === Pilonidal sinus (PNS): a sinus tract, or small channel, that may originate from the source of infection and open to the surface of the skin. Material from the cyst drains through the pilonidal sinus. A pilonidal cyst is usually painful, but if it is a draining sinus, the pressure is relieved and the patient might not feel pain.
Freezing food preserves it from the time it is prepared to the time it is eaten. Since early times, farmers, fishermen, and trappers have preserved grains and produce in unheated buildings during the winter season. Freezing food slows decomposition by turning residual moisture into ice, inhibiting the growth of most bacterial species. In the food commodity industry, there are two processes: mechanical and cryogenic (or flash freezing). The freezing kinetics is important to preserve the food quality and texture. Quicker freezing generates smaller ice crystals and maintains cellular structure. Cryogenic freezing is the quickest freezing technology available due to the ultra low liquid nitrogen temperature −196 °C (−320 °F). Preserving food in domestic kitchens during modern times is achieved using household freezers. Accepted advice to householders was to freeze food on the day of purchase. An initiative by a supermarket group in 2012 (backed by the United Kingdom's Waste & Resources Action Programme) promotes the freezing of food "as soon as possible up to the product's 'use by' date". The Food Standards Agency was reported as supporting the change, provided the food had been stored correctly up to that time.
=== Theories of origin === The most commonly held of the three theories of tofu's origin maintains that tofu was discovered by Liu An (179–122 BC), a Han dynasty prince. While plausible, the paucity of reliable sources for this period makes this difficult to conclusively determine. In Chinese history, important inventions were frequently attributed to important leaders and figures of the time. It was used as a cheaper option to meat. In 1960, a stone mural unearthed from an Eastern Han dynasty tomb provided support for the theory of the Han origin of tofu; however some scholars maintain that tofu during the Han dynasty was rudimentary and lacked the firmness and taste for it to be considered as tofu. Another theory suggests that the production method for tofu was discovered accidentally when a slurry of boiled, ground soybeans was mixed with impure sea salt. Such sea salt would probably have contained calcium and magnesium salts, allowing the soy mixture to curdle and produce a tofu-like gel. The last group of theories maintains that the ancient Chinese learned the method for curdling soy milk by emulating the milk curdling techniques of the Mongolians. The primary evidence for this theory is the etymological similarity between the Chinese term rǔfǔ (乳腐), which literally means "milk curd", used during Sui dynasty (AD 581–618), for dishes with a consistency like yogurt or soft cheese, later influenced by Mongolian milk products and methods of production, and the term dòufu (豆腐, "bean curd") or tofu.
Sources: en.wikipedia.org
Insufficient recognition has been given to Paulescu, the distinguished Romanian scientist, who at the time when the Toronto team were commencing their research had already succeeded in extracting the antidiabetic hormone of the pancreas and proving its efficacy in reducing the hyperglycaemia in diabetic dogs.
Heroin is produced from opium, which is regulated differently around the world. Unlike coca leaves in Peru—handled exclusively by the state monopoly, the National Coca Company (ENACO)—there is no state company dedicated to the commercialization of opium and its derivatives. While international treaties—such as the Single Convention on Narcotic Drugs (1961)—require strict state control or monopoly over the legal production and commercialization of opium for medical and scientific purposes, in practice, only a few countries maintain such a state monopoly today. Notably, India operates a state monopoly through the Government Opium and Alkaloid Factories (GOAF), also known as Opium and Alkaloid Works, which is responsible for processing raw opium into alkaloids for the pharmaceutical industry and managing the legal opium trade for medical and scientific use. Legal opium production in India, as well as in countries such as Turkey, Australia, France, Japan, and the UK, supplies licensed pharmaceutical manufacturers under close supervision to prevent diversion to illicit markets.
SIMS is a mass spectrometry method to measure small-scale elemental and isotopic variations of samples. Its ability to measure in spots with a narrow diameter (10–40 μm) makes it a useful tool to date small (<100 μm) mineral grains and individual domains within a single crystal. SIMS can achieve a precision of ~3%. Sensitive high-resolution ion microprobe (SHRIMP) is widely regarded as a powerful tool among SIMS. SIMS analyzes the mineral surface (a few μm) composition by sputtering the surface with a focused primary ion beam under vacuum. The secondary ions liberated from the mineral are accelerated, measured and analyzed in the mass spectrometer. Sample are analysed in rotation with a standard of known elemental or isotopic ratios in order to determine the ratios in the sample for dating.
=== Pyrimidine derivatives === Pazopanib is a multi-targeted tyrosine kinase receptor inhibitor. The structure is formed by indazole, pyrimidine and a benzene ring. If the indazole ring is kept the same, replacing 5-amino-2-methylbenzenesulfonamide with another arylamine at position 2 of the pyrimidine, gives inhibitory effect on VEGFR-2 and c-Kit. For R2, two groups can show this effect on the compound, an ether group on one, and on the other a chloride group. When substituents are added on pazopanib with different electronic effects at the benzene ring the inhibition to the kinase changes. Regarding the steric effect on position R1 and R2, a hydrogen in position R1 and a trifluoro-ether in R2 have the most inhibitory effect on VEGFR-2, which can be the effect of the electronegative groups. There is a steric hindrance of the indazole heterocycle, which can play an important role in the interaction with the tyrosine kinase receptor inhibition.
Ten years later, Harvard University removed the book's anthropodermic bindings due to ethical concerns. Not all putatively anthropodermic books have been subject to such testing. A library or archive may decline testing if their policies prohibit any technically destructive tests; peptide mass fingerprinting requires removing a minuscule portion of the book's bindings. Other collections may be unwilling to suffer possible negative publicity if a book is confirmed as bound in human skin. Many others still remain to be tested, including those bound in the skin of executed criminals. While such books are generally treated as legitimate, due to their clear provenance compared to the mysterious or untraceable origins of most anthropodermic books, it is possible individual cases may be fraudulent. Such cases are further complicated by requests by descendants to return such books to the families, after which they may be buried or destroyed before they can be tested. Themes emerge in what purportedly anthropodermic books turn out to be legitimate or illegitimate. Books that call attention to the race of those whose skin was used to bind them, for instance, generally turn out to be frauds. Most legitimate anthropodermic books were owned or bound by physicians, and many of them are dedicated to the practice of medicine. In her book Dark Archives, the anthropodermic bibliopegy expert Megan Rosenbloom connects this to changing standards of medical ethics and the relatively recent emergence of the concept of consent in medicine.
Sources: en.wikipedia.org
==== Endocrine and metabolic disorders ==== Several endocrine conditions can cause proximal muscle weakness and laboratory abnormalities that mimic inflammatory myopathy. This includes thyroid issues (hypothyroidism or hyperthyroidism), where your thyroid hormones are either too high or too low. Also, it’s important to consider Cushing syndrome and acromegaly.
Glycogenesis is the process of glycogen synthesis or the process of converting glucose into glycogen in which glucose molecules are added to chains of glycogen for storage. This process is activated during rest periods following the Cori cycle, in the liver, and also activated by insulin in response to high glucose levels.
==== Netherlands ==== A brand called UGGO is sold in the Netherlands, which offers several different flavors of cream soda. The Surinamese soft drink brand Fernandes, widely available in the country, sells cream soda under the name Green Punch; as the name implies, it is green in color. Asian (especially Chinese) supermarkets also sell Schweppes Cream Soda, which is imported from Hong Kong. A&W is sold in some supermarkets. Old Jamaica Cream Soda (Jamaica) is also sold in the Netherlands.
The Recommended Daily Intake (RDA) for preformed supplemental vitamin A for adult men and women is 900 and 700 Retinol Activity Units(RAE)/day, respectively, or about 3,000 IU and 2,300 IU. In pregnancy, the vitamin A RDA is 750–770 RAE/day (about 2,500–2,550 IU). During lactation, the RDA increases to 1,200–1,300 RAE/day (about 4,000–4,300 IU, with differences depending on age). Retinol Activity Units can only be converted to IU (International Units) when the source of the vitamin A is known. The IU values listed above do not apply to food sources of vitamin A. Too much vitamin A in retinoid form can be harmful. The body converts the dimerized form, carotene, into vitamin A as it is needed, so high levels of carotene are not toxic, whereas the ester (animal) forms are. The livers of certain animals, especially those adapted to polar environments, such as polar bears and seals, often contain amounts of vitamin A that would be toxic to humans. Thus, vitamin A toxicity is typically reported in Arctic explorers and people taking large doses of synthetic vitamin A. The first documented death possibly caused by vitamin A poisoning was that of Xavier Mertz, a Swiss scientist, who died in January 1913 on an Antarctic expedition that had lost its food supplies and fell to eating its sled dogs. Mertz may have consumed lethal amounts of vitamin A by eating the dogs' livers. Vitamin A acute toxicity occurs when a person ingests vitamin A in large amounts more than the daily recommended value in the threshold of 25,000 IU/kg or more.
It has been shown that injection of peptide amphiphile solutions in vivo leads to in situ gel formation due to the presence of counterions in physiological solutions. This, along with the complete biodegradability of the materials, suggests numerous applications in in vitro and in vivo therapies.
Sources: en.wikipedia.org
It is a synthetic cyclic heptapeptide modelled on alpha-melanocyte-stimulating hormone. A lactam bridge links two side chains, forming a ring that stabilises the molecule against proteolysis. It belongs to the broader melanocortin peptide family.
No national medicines agency has approved melanotan-2 for clinical use. Afamelanotide, a related but distinct peptide, holds a marketing authorisation in the European Union for a rare photosensitivity disorder. Melanotan-2 itself is handled as a laboratory chemical.
Its broad activity across melanocortin receptors makes it a tool for probing pigmentation, appetite and vascular signalling. Early trials recorded skin darkening and other effects that were not the original focus of the work. Those observations generated hypotheses that later studies have examined.
No regulatory agency has authorised melanotan-2 as a medicine for any indication. It circulates mainly as a research chemical or through unregulated channels. As a result, identity, purity and content are not independently guaranteed.