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 2026-07-24. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Melanocytes are the pigment-producing cells of the skin, and they carry melanocortin-1 receptors on their surface. When the receptor is activated, cyclic adenosine monophosphate rises inside the cell and raises the activity of enzymes such as tyrosinase, which increases melanin output. Melanotan-2 binds melanocortin-1 receptors in vitro and in animal models, and this binding is generally described as the basis for the tanning effect. Other receptors account for different effects: melanocortin-4 receptors contribute to appetite and erectile signalling, while melanocortin-3 and melanocortin-5 receptors contribute to energy balance and exocrine function.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Compound class | Synthetic cyclic heptapeptide | Alpha-MSH analogue containing a D-phenylalanine residue |
| Molecular formula | C50H69N15O9 | Average molecular mass approximately 1024.2 g/mol |
| Appearance | White to off-white lyophilised powder | Normally supplied as a freeze-dried solid in a sealed vial |
| Solubility | Freely soluble in water and polar solvents | Dissolves readily in aqueous buffers and in alcohol-water mixtures |
| Receptor targets | MC1R, MC3R, MC4R, MC5R | Acts as a non-selective melanocortin receptor agonist |
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.
Analytical confirmation of identity relies on mass spectrometry, most often coupled to liquid chromatography. Reversed-phase high-performance liquid chromatography separates the peptide from related impurities and provides a purity estimate based on peak area. Electrospray ionization mass spectrometry then confirms the expected molecular mass, while tandem mass spectrometry can map the fragment sequence. For research-grade material, these two techniques together form the standard minimum. Purity figures reported by vendors are frequently not traceable to an independent laboratory.
Independent verification is central to quality control because the compound is not produced under pharmaceutical manufacturing standards. Third-party laboratories can measure purity, identity, residual solvents, and microbial contamination, though the scope of testing varies between services. Reported analyses of vendor samples have shown batch-to-batch variation in peptide content and the presence of truncated or oxidized species. How much of this variation reflects synthesis conditions versus storage and shipping is not well characterized. No harmonized reference standard exists for the material as sold.
The substances that give chili peppers their pungency (spicy heat) when ingested or applied topically are capsaicin (8-methyl-N-vanillyl-6-nonenamide) and several related chemicals, collectively called capsaicinoids. Pure capsaicin is a hydrophobic, colorless, odorless, and crystalline-to-waxy solid at room temperature. The quantity of capsaicin varies by variety, and depends on growing conditions. Water-stressed peppers usually produce stronger fruits. When a habanero plant is stressed, for example by shortage of water, the concentration of capsaicin increases in some parts of the fruit. When peppers are consumed by mammals such as humans, capsaicin binds with pain receptors in the mouth and throat, potentially evoking pain via spinal relays to the brainstem and thalamus where heat and discomfort are perceived. However, birds are unable to perceive the hotness and so they can eat some of the hottest peppers. The intensity of the "heat" of chili peppers is commonly reported in Scoville heat units (SHU), invented by American pharmacist Wilbur Scoville in 1912. Historically, it was a measure of the dilution of an amount of chili extract added to sugar syrup before its heat becomes undetectable to a panel of tasters; the more it has to be diluted to be undetectable, the more powerful the variety, and therefore the higher the rating. Since the 1980s, spice heat has been assessed quantitatively by high-performance liquid chromatography (HPLC), which measures the concentration of heat-producing capsaicinoids, typically with capsaicin content as the main measure.
== Sports == Canberra Raiders, Australian rugby league football club Chitwan Rhinos, a professional Twenty20 cricket franchise representing Chitwan District, Nepal in the Nepal Premier League (NPL) Colorado Rockies, a Major League Baseball team Cincinnati Reds, another Major League Baseball team Colorado Rockies (NHL), a former National Hockey League team Cristiano Ronaldo, Portuguese footballer Commonwealth record in athletics Commonwealth record in swimming
In an open letter to the United Kingdom government the British Society for Middle Eastern Studies (BRISMES) called the perceived systematic targeting of universities, schools, laboratories and libraries as a component of a genocidal strategy aimed at destroying the Palestinian educations system in Gaza. The chair of the Committee on the Rights of the Child stated on 8 February, "The rights of children living under the state of Israel’s effective control are being gravely violated at a level that has rarely been seen in recent history." The Gulf Cooperation Council called on the UN Human Rights Council to "shoulder their responsibility in ending the tragedy of the children in Gaza and securing their right to live, safety, and protection". The UN Population Fund stated in late-March 2024 that "Pregnant women and new mothers face a constant struggle to keep themselves and their newborns alive." In response to reports that one-third of under-two-year-olds in northern Gaza were acutely malnourished, UNICEF's James Elder, stated, "That is a terrifying number". The UN added Israel to a blacklist of countries that violate the rights of children. In June 2024, the United Nations stated that grave violations against children in conflict zones had increased 155 percent globally, due especially to explosive weapons used in the Gaza Strip. In September 2024, a UN committee stated Israel had committed severe breaches against children's rights in Gaza, saying, "The outrageous death of children is almost historically unique. This is an extremely dark place in history.
Epidurals can provide temporary relief but are not generally recommended as they can cause cysts to enlarge. Extraction of fluid can provide limited or no relief depending on rate the cysts refill and the need to repeat the procedure. Removal of the cyst results in irreversible damage to the intersecting spinal nerve. Although fibrin-glue therapy initially had been thought to be a promising therapy in the treatment of these cysts, there have been multiple problems associated with the fibrin glue therapy including seepage of fibrin. It is no longer recommended for use at present by the Health Department in some countries and neurosurgeons previously performing the procedures. Nevertheless, all types of surgical treatment pose common risks, including neurological deficits, infection and inflammation, spinal headache, urinary disturbances, and leakage of cerebrospinal fluids.
Sources: en.wikipedia.org
After synthesizing and purifying the core, the carbohydrate layer is added to its surface. Common coating materials are typically polyhydroxy oligomers such as cellobiose, citrate, lactose, and sucrose. This layer seems to be important for the properties of aquasomes, as it influences several drug characteristics including adsorption, molecular stability, and conformation (shape), and acts as a dehydroprotectant. The addition of the carbohydrate layer to the surface of the nanocrystalline core is commonly carried out by passive adsorption through incubation and sonication. Similar to the processing of the core, the carbohydrate layer is subjected to centrifugation, washing, and further sonification followed by heated air drying. Finally, the bioactive molecule of interest is loaded into the carbohydrate layer. This process typically occurs through either lyophilization or passive adsorption, and the fully functionalized aquasome is then characterized.
=== Radiation shielding === Depleted uranium is the best radiation shielding by weight, due to the high atomic weight of the uranium atoms; materials are more able to block radioactivity the higher their atomic weight, and uranium is one of the heaviest natural elements. Lead, the heaviest stable element, is the most common low-cost alternative, but a lead shield needs to be about three times as thick as a DU shield to provide the equivalent protection. Uranium also has by far a higher melting point 2,070 °F (1,130 °C), and its tensile strength is similar to that of steel. Industrial radiography cameras include a very high activity gamma radiation source (typically Ir-192 with an activity above 10 TBq). Depleted uranium is often used in the cameras as a shield to protect individuals from the gamma source. Typically, the uranium shield is supported and enclosed in polyurethane foam for thermal, mechanical and oxidation protection.
Naturally occurring ytterbium (70Yb) is composed of seven stable isotopes: 168Yb, 170Yb–174Yb, and 176Yb, with 174Yb being the most abundant (31.90% natural abundance). 30 radioisotopes have been characterized, with the most stable being 169Yb with a half-life of 32.014 days, 175Yb with a half-life of 4.185 days, and 166Yb with a half-life of 56.7 hours. All of the remaining radioactive isotopes have half-lives that are less than 2 hours, with the majority of them being less than 20 minutes. This element also has 18 meta states, with the most stable being 169mYb (half-life 46 seconds). The known isotopes of ytterbium range from 149Yb to 189Yb. The primary decay mode before the most abundant stable isotope, 174Yb is electron capture giving thulium isotopes; the primary mode after is beta emission giving lutetium isotopes. Of interest to modern quantum optics, the different ytterbium isotopes follow either Bose–Einstein statistics or Fermi–Dirac statistics, leading to different behavior in optical lattices.
== Southern Rhodesians in other theatres == In addition to the main deployments, Southern Rhodesian servicemen served in other theatres of the war. Rhodesian sailors in the Royal, South African and Merchant Navies crewed ships in many parts of the world, including the Indian Ocean, the Arctic and the Pacific. No. 237 (Rhodesia) Squadron operated in Iran and Iraq in 1942–43, guarding oil wells and pipelines and supporting the British Tenth Army. Closer to home, Southern Rhodesian military surveyors contributed to the preliminary planning work for the Allied invasion of Madagascar in May 1942, and landed at Diego Suarez with the invading forces. They remained there long after the Vichy French garrison agreed to an armistice at Ambalavao on 6 November 1942—the last Rhodesian left the island in October 1943.
Myomesin-2, also known as M-protein, is a protein that in humans is encoded by the MYOM2 gene. M-protein is expressed in adult cardiac muscle and fast skeletal muscle, and functions to stabilize the three-dimensional arrangement of proteins comprising M-band structures in a sarcomere.
Sources: en.wikipedia.org
Keven Verdun Thacker, Chief Executive Officer, the Lighting Association. For services to Domestic Energy Efficiency. Noel Thatcher. For services to Athletics for Disabled People. Marshall Thew, . For charitable and community services in Wirral. Gwendoline Marian Thomas, Executive Officer, Department of Social Security. John Edwin Thomas, Leading Firefighter, West Midlands Fire Service. For services to the Fire Service. Marina Ann Thomas, School Crossing Patrol, Newton Abbot, Devon County Council. For services to Road Safety. Martyn Edmund Thomas, Managing Director, Sulzer (UK) Pumps Ltd. For services to the Engineering Industry. Kenneth Charles Thompson, Pay Band 8, the Employment Service, Department for Education and Employment. Neil Dennis Thompson, Sub-Officer (Retained), Nottinghamshire Fire and Rescue Service. For services to the Fire Service. Douglas Albert Till. For services to Training in Worcester. Anthony Richard Shaw Timmis. For services to the Building Industry and to the community in Yeovil, Somerset. Dawn Pauline Toomey, Higher Executive Officer, Office for National Statistics. John Joseph Tovey. For services to Tourism in Cumbria. Stephanie Catherine Townsend, Executive Officer, Ministry of Agriculture, Fisheries and Food. Rita Trevennen. For services to the Citizens' Advice Bureau in Penzance, Cornwall. Arthur George Cecil Trollope. For services to Conservation and to the community in London. Doris A. P. Troup, Member, Parkinson's Disease Society, Aberdeen. For services to Health Care. Brian Tuckley, Safety Officer, Institute of Food Research.
The bioavailability of spironolactone when taken by mouth is 60 to 90%. The bioavailability of spironolactone and its metabolites increases significantly (+22–95% increases in levels) when spironolactone is taken with food, although it is uncertain whether this further increases the therapeutic effects of the medication. The increase in bioavailability is thought to be due to promotion of the gastric dissolution and absorption of spironolactone, as well as due to a decrease of the first-pass metabolism. The relationship between a single dose of spironolactone and plasma levels of canrenone, a major active metabolite of spironolactone, has been found to be linear across a dose range of 25 to 200 mg spironolactone. Steady-state concentrations of spironolactone are achieved within 8 to 10 days of treatment initiation. Little or no systemic absorption has been observed with topical spironolactone.
=== 31 May === One person was killed by Russian shelling in Vovchansk Raion in Kharkiv Oblast, while three people, including two children, were injured by Russian shelling in Kherson Oblast. One person was also killed by Russian shelling in Donetsk Oblast. Officials in the Russian-installed Luhansk People's Republic said that five people were killed and 19 others were injured after Ukrainian artillery hit a poultry farm. The State Border Guard Service of Ukraine reported that Russian troops had blown up a road that links Ukraine's Chernihiv Oblast with Russia's Bryansk Oblast, saying that the incident occurred at the tripoint between Ukraine, Russia and Belarus. Ukraine claimed that Russian-installed officials in occupied Luhansk were threatening to withhold the wages of workers who refused to open accounts at Russian banks. The Russian defence ministry claimed its forces had pushed out Ukrainian forces from positions around Krasnohorivka and Yasynuvata in Donetsk Oblast. A fire broke out at the Afipsky oil refinery in Russia's Krasnodar Krai. Veniamin Kondratyev, Governor of the region, blamed the fire on a Ukrainian drone strike. The fire was put out with minimal damage and no casualties. Another drone was reported to have crashed into the Ilsky refinery. The governor of Belgorod Oblast announced the beginning of evacuations of children from areas affected by Ukrainian shelling, saying that 300 children would be taken to Voronezh, about 250 km (160 mi) away, while another 1,000 children would be evacuated to other regions over the coming days.
=== Historical incidents === On 16 July 1934, in Kummersdorf, Germany, a propellant tank containing an experimental monopropellant mixture consisting of hydrogen peroxide and ethanol exploded during a test, killing three people. During the Second World War, doctors in German concentration camps experimented with the use of hydrogen peroxide injections in the killing of human subjects. In December 1943, the pilot Josef Pöhs died after being exposed to the T-Stoff of his Messerschmitt Me 163. In June 1955, Royal Navy submarine HMS Sidon sank after leaking high-test peroxide in a torpedo caused it to explode in its tube, killing twelve crew members; a member of the rescue party also succumbed. In April 1992, an explosion occurred at the hydrogen peroxide plant at Jarrie in France, due to technical failure of the computerised control system and resulting in one fatality and wide destruction of the plant. Several people received minor injuries after a hydrogen peroxide spill on board a Northwest Airlines flight from Orlando, Florida to Memphis, Tennessee on 28 October 1998. The sinking of the Russian submarine K-141 Kursk is attributed to the explosion of one of its hydrogen peroxide-fueled torpedoes. On 15 August 2010, a spill of about 30 US gallons (110 L) of cleaning fluid occurred on the 54th floor of 1515 Broadway, in Times Square, New York City. The spill, which a spokesperson for the New York City Fire Department said was of hydrogen peroxide, shut down Broadway between West 42nd and West 48th streets as fire engines responded to the hazmat situation.
Sources: en.wikipedia.org
No. It is a laboratory-made peptide, while the natural hormone is alpha-melanocyte-stimulating hormone, a longer peptide produced by the pituitary gland and by skin cells. Melanotan-2 mimics only a short active region of that hormone and contains non-natural residues such as D-phenylalanine.
No approved regulatory indication exists in major markets. An approval exists for a different peptide, afamelanotide, which is used for a rare photosensitivity disorder called erythropoietic protoporphyria. Melanotan-2 itself remains a research compound with no cleared clinical role.
Melanocortin-1 receptors on melanocytes are the receptor most closely linked to pigment production. The peptide is not selective, however, and also activates melanocortin-3, melanocortin-4, and melanocortin-5 receptors. That lack of selectivity is the usual explanation offered for both its range of observed effects and its off-target effects.
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.