The short version of alpha-MSH analog fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
Regulatory treatment varies by country. In the United States, melanotan-2 is not approved for any indication, and products marketed for human use fall outside the approved drug framework. Some other jurisdictions have placed it under prescription controls or listed it as a prohibited or restricted substance. Online listings frequently describe the material as a research chemical, a category that does not carry the same manufacturing and labelling requirements as approved medicines.
Solid peptide material is generally stable when kept cold and dry. Common practice is storage at -20 degrees Celsius or lower, with desiccant and protection from light. Repeated freeze-thaw cycles and exposure to moisture are associated with degradation, aggregation, or loss of material. Once dissolved, stability depends on solvent, concentration, and temperature, and solutions are usually treated as short-lived unless stability data support longer periods. Handling notes typically emphasise minimising time at ambient temperature.
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.
Melanotan II is a synthetic cyclic heptapeptide with the sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, corresponding to a molecular formula of C50H69N15O9 and a monoisotopic mass near 1024 daltons. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, a peptide hormone produced by cleavage of proopiomelanocortin. A lactam bridge between the aspartate and lysine side chains closes the ring, and the C-terminal amide removes a free carboxyl group. Both modifications increase resistance to enzymatic degradation compared with the linear parent hormone. Four substitutions distinguish it from afamelanotide, the linear analogue studied under the name melanotan I.
| Property | Value | Notes |
|---|---|---|
| Solid-state storage | -20 degrees Celsius or lower | Desiccated and protected from light |
| Solution stability | Short and method-dependent | Confirm by stability testing |
| Purity assessment | Reversed-phase HPLC | Reported as area percent |
| Identity confirmation | LC-MS or comparable method | Mass match against expected value |
| Common synonyms | MT-II; melanotan II | Informal and catalogue names |
Because the substance circulates mainly through informal markets, verification is a recurring theme in technical discussion. Independent analyses have found that labeled content and actual content can diverge, and that purity varies between samples. Analytical laboratories use reversed-phase chromatography to separate components and mass spectrometry to confirm identity. Isotope-labeled internal standards improve quantification in complex matrices. Such methods describe what a sample contains but say nothing about its sterility, lawful status, or suitability for any use. Open questions remain about how consistently testing is applied across the supply chain.
Regulatory treatment of this peptide varies by country. It holds no marketing authorization as a medicine in the United States, the European Union, or most other jurisdictions. Some countries classify products containing it as prescription-only or unlicensed medicines, which restricts lawful supply. Authorities have issued public notices warning that unregulated products may contain undeclared or incorrect ingredients. The molecule also appears on prohibited lists for competitive sport. These measures address supply oversight rather than any approved therapeutic role.
Published research on the compound remains limited. Much of the human data comes from small, early-stage studies rather than large controlled trials, and several questions about effects and variability between individuals remain open. Investigators have examined receptor activity, pigment pathways, and related physiological responses in laboratory and animal models. Findings from those models do not automatically translate to human outcomes. Reviews frequently note the scarcity of rigorous clinical evidence and call for better-characterized study material.
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.
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.
Pharmacologically, melanotan-2 behaves as a non-selective agonist across the melanocortin receptor family. Binding at MC1R on dermal melanocytes promotes eumelanin synthesis, which underlies the tanning response described in early human work. Activity at the centrally expressed MC4R receptor is associated with reported effects on appetite and erectile function. Because the peptide does not discriminate strongly among receptor subtypes, attributing any single observed effect to one receptor pathway is generally not possible without selective antagonists or receptor knockout models.
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.
In his return game, he had the fifth highest percentage of first serve points won that year at 32.4%. His second serve has been a weakness for him in his earlier years, yet he has managed to turn it into a consistent strength. Zverev hit the most double faults on tour in 2016 and 2020. While it has improved since, it can still cause trouble for the German in big points.
The divisions between the elite and the lawless led to the formation of a Cossack army, beginning in 1667 under Stenka Razin, and ultimately to the failure of Razin's rebellion. Stenka Razin was born into an elite Cossack family, and had made many diplomatic visits to Moscow before organizing his rebellion. The Cossacks were Razin's main supporters, and followed him during his first Persian campaign in 1667, plundering and pillaging Persian cities on the Caspian Sea. They returned in 1669, ill and hungry, tired from fighting, but rich with plundered goods. Russia tried to gain support from the old Cossacks, asking the ataman, or Cossack chieftain, to prevent Razin from following through with his plans. But the ataman was Razin's godfather, and was swayed by Razin's promise of a share of expedition wealth. His reply was that the elite Cossacks were powerless against the band of rebels. The elite did not see much threat from Razin and his followers either, although they realized he could cause them problems with the Muscovite system if his following developed into a rebellion against the central government. Razin and his followers began to capture cities at the start of the rebellion, in 1669. They seized the towns of Tsaritsyn, Astrakhan, Saratov, and Samara, implementing democratic rule and releasing peasants from slavery as they went. Razin envisioned a united Cossack republic throughout the southern steppe, in which the towns and villages would operate under the democratic, Cossack style of government.
== External links == MedlinePlus Encyclopedia: Gamma-glutamyl transpeptidase (GGT) blood test gamma-Glutamyltransferase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) GGT - Lab Tests Online Overview of all the structural information available in the PDB for UniProt: P19440 (Gamma-glutamyltransferase 1) at the PDBe-KB.
== Computational neuroscience == Metastability in the brain is a phenomenon studied in computational neuroscience to elucidate how the human brain recognizes patterns. Here, the term metastability is used rather loosely. There is no lower-energy state, but there are semi-transient signals in the brain that persist for a while and are different than the usual equilibrium state.
For example, genetic mutations in pseudouridine synthases cause mitochondrial myopathy, sideroblastic anemia (MLASA) and dyskeratosis congenital. Compared to the modifications identified from other RNA species like tRNA and rRNA, the amount of identified modifications on mRNA is very small. One of the biggest reasons why mRNA modifications are not so well known is missing research techniques. In addition to the lack of identified modifications, the knowledge of associated proteins is also behind other RNA species. Modifications are results of specific enzyme interactions with the RNA molecule. Considering mRNA modifications most of the known related enzymes are the writer enzymes that add the modification on the mRNA. The additional groups of enzymes readers and erasers are for most of the modifications either poorly known of not known at all. For these reasons there has been during the past decade huge interest in studying these modifications and their function.
Sources: en.wikipedia.org
=== Vaccination and information === Modern societies are facing the challenge of "rational" exemption, i.e. the family's decision to not vaccinate children as a consequence of a "rational" comparison between the perceived risk from infection and that from getting damages from the vaccine. In order to assess whether this behavior is really rational, i.e. if it can equally lead to the eradication of the disease, one may simply assume that the vaccination rate is an increasing function of the number of infectious subjects:
29 September The kārearea is named Bird of the Year for 2025. The government announces a reform of the earthquake-prone building classification system which reduces the amount of buildings nationwide being classed as earthquake-prone by 55%. 30 September: Carter Holt Harvey confirms plans to close its Tokoroa plywood plant in November 2025, affecting 119 jobs. A measles case linked to international travel is reported in Queenstown, bringing the total number of cases to five.
=== Column === The column is a glass or plastic cylinder packed with beads of resin and filled with buffer solution. It is normally mounted vertically with the buffer flowing downward from top to bottom. A glass frit at the bottom of the column retains the resin beads in the column while allowing the buffer and dissolved proteins to exit.
polycyclic structures (e.g. tetrodotoxin) compounds with a strong electron-withdrawing group attached to the acyl carbon (e.g. N,N-dimethyltrifluoroacetamide) compounds with donor groups that are poorly conjugated with the potential carbonyl group (e.g. cyclol) compounds with sulfur atoms bonded to the anomeric centre (e.g., S-acylated-1,8-naphthalenedithiol) These compounds were used to study the kinetics of tetrahedral intermediate decomposition into its respective carbonyl species, and to measure the IR, UV, and NMR spectra of the tetrahedral adduct.
{\displaystyle {\begin{aligned}\rho \left({\partial _{t}u_{r}}+u_{r}{\partial _{r}u_{r}}+u_{z}{\partial _{z}u_{r}}\right)&=-{\partial _{r}p}+\mu \left({\frac {1}{r}}\partial _{r}\left(r{\partial _{r}u_{r}}\right)+{\partial _{z}^{2}u_{r}}-{\frac {u_{r}}{r^{2}}}\right)+\rho g_{r}\\\rho \left({\partial _{t}u_{z}}+u_{r}{\partial _{r}u_{z}}+u_{z}{\partial _{z}u_{z}}\right)&=-{\partial _{z}p}+\mu \left({\frac {1}{r}}\partial _{r}\left(r{\partial _{r}u_{z}}\right)+{\partial _{z}^{2}u_{z}}\right)+\rho g_{z}\\{\frac {1}{r}}\partial _{r}\left(ru_{r}\right)+{\partial _{z}u_{z}}&=0.\end{aligned}}}
Sources: en.wikipedia.org
Slovakia: Prime Minister Robert Fico criticized the actions of the United States, stating that "International law does not apply, military power is used without the mandate of the UN Security Council, and everyone who is great and strong does what he wants to promote their own interests," and that "I resolutely reject such a disruption of international law, as I did in the Iraq war, in the denial of Kosovo as a sovereign state, or in the use of Russian military power in Ukraine." He also suggested that the European Union should apply the same standards that were used with Russia when it invaded Ukraine, saying that "Either the use of American military force in Venezuela will be condemned and be consistent with attitudes to the war in Ukraine, or, as usual, remain pharisaical." Spain: The Foreign Ministry called for "de-escalation and moderation", and for compliance with "international law and the principles of the UN charter" adding that the ministry was "prepared to offer its good offices to achieve a peaceful and negotiated solution". They reiterated that they did not recognize the results of the 2024 Venezuelan presidential election and that Spain "has welcomed, and will continue to welcome, tens of thousands of Venezuelans who have had to leave their country for political reasons." On 4 January 2026, Brazil, Spain, Chile, Colombia, Mexico, and Uruguay issued a joint statement to express their "profound concern and firm rejection of the military actions carried out unilaterally in Venezuelan territory" by the United States.
malnutrition and vitamin deficiency immunodeficiency poor oral hygiene recent illness (especially acute necrotizing ulcerative gingivitis, measles, malaria, or kwashiorkor), social and environmental factors such as maternal malnutrition and closely spaced pregnancies that result in offspring with weakened immune systems In 2026 a newly discovered bacterium, Treponema A, was found in tissue samples from current sufferers of the disease as well as in historic samples. Further research is needed to establish if this could be a causative factor.
Iced coffee is prepared many different ways in the US, including cold-brew coffee and chilled conventional coffee. Iced coffee can be made from cold-brew coffee, for which coffee grounds are soaked for several hours and then strained. The next day, the grounds get filtered out. The result is a very strong coffee concentrate that is usually mixed with milk and sweetened. Many coffee retailers simply use hot-brewed coffee in their iced coffee drinks. Starbucks specifically uses the double-strength method in which the coffee is brewed hot with twice the amount of grounds. With this method, the melted ice does not dilute the strength and flavor of the coffee. Unlike the cold-brew process, this method does not eliminate the acidity inherent in hot-brewed coffee.
stimulant effects of caffeine), and those are listed where they are relevant and well-documented. Internet claims for individual chemicals, or compound synergies, such as preventing dental cavities (speculative but unproven effect of the alkaloid trigonelline with in vitro bacterial attachment research, but missing in vivo research on any health effects), preventing kidney stones, or negative effects, also have been avoided.
Sources: en.wikipedia.org
Laboratory confirmation typically combines retention time matching on a chromatographic system with mass measurement. A reference standard of known identity is needed for a meaningful comparison. Sequence-level techniques can add further confirmation.
There is no single harmonised standard governing these products, and manufacturing conditions differ. Impurities may include truncated sequences, oxidation products, residual solvents, and counter-ions. Independent testing is often the only way to characterise a given lot.
Reported studies have looked at pigmentation, photoprotection, and metabolic or appetite-related endpoints in small experimental settings. Much of the evidence base is early-stage and limited in size. Questions about long-term effects and clinical relevance remain open.
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.