Everything below concerns alpha-MSH analogue. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-05-10. Numbers and descriptions here follow the published literature rather than marketing material.
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.
Identity and purity are assessed with chromatographic and mass spectrometric techniques. Reversed-phase high-performance liquid chromatography separates the target peptide from related impurities and degradation products, and the resulting retention time is compared against a reference standard. Mass spectrometry, often coupled to liquid chromatography, confirms molecular mass. Amino acid analysis or peptide mapping can provide additional sequence-level confirmation when required. Results are only as reliable as the reference materials used alongside them.
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.
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.
| 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 |
Melanotan-2 appears on the World Anti-Doping Agency prohibited list within the peptide hormone class, and several national regulators treat it as an unapproved prescription substance. Some countries restrict importation or sale for personal use. Because the compound is widely traded as a research chemical, the practical legal picture differs between jurisdictions and shifts over time. Human safety data covering long periods are limited, and whether repeated pigmentation changes carry any lasting risk to melanocytes remains an open question.
Freeze-dried melanotan-2 is normally kept as a desiccated powder at minus twenty degrees Celsius or lower, shielded from light and moisture. Peptides of this size degrade through hydrolysis, oxidation and deamidation, and each pathway accelerates as temperature and water activity rise. Repeated freeze-thaw cycles promote aggregation and loss of material, so aliquoting a stock solution before freezing is standard laboratory practice. Once dissolved, the solution is markedly less stable than the powder. In laboratory work, solutions are generally refrigerated and used within days rather than kept for months.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or oxidised impurities. Mass spectrometry, most often coupled to liquid chromatography, confirms molecular mass and detects substitutions that chromatography alone may miss. Amino acid analysis and peptide mapping supply additional structural evidence, while nuclear magnetic resonance is reserved for full structural confirmation. Laboratories that examine samples sold online report wide variation in actual content, with some vials containing little or none of the labelled material.
Receptor-binding studies classify melanotan II as a non-selective melanocortin agonist. It interacts with MC1R, MC3R, MC4R and MC5R, with reported affinities in the low nanomolar range and no strong subtype preference. Activation of MC1R on dermal melanocytes shifts pigment synthesis toward eumelanin, the dark polymer deposited in melanosomes and transferred to keratinocytes. Because the same peptide engages MC4R in the hypothalamus, it also appears in animal work on food intake and erectile response, which is why it is discussed in both pigment and metabolic research. Which receptor populations dominate after systemic exposure in humans is not fully established.
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.
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.
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.
Twenty chemical elements are known to be required to support human biochemical processes by serving structural and functional roles, and there is evidence for a few more. Oxygen, hydrogen, carbon and nitrogen are the most abundant elements in the body by weight and make up about 96% of the weight of a human body. Calcium makes up 920 to 1200 grams of adult body weight, with 99% of it contained in bones and teeth. This is about 1.5% of body weight. Phosphorus occurs in amounts of about 2/3 of calcium, and makes up about 1% of a person's body weight. The other major minerals (potassium, sodium, chlorine, sulfur and magnesium) make up only about 0.85% of the weight of the body. Together these eleven chemical elements (H, C, N, O, Ca, P, K, Na, Cl, S, Mg) make up 99.85% of the body. The remaining ≈18 ultratrace minerals comprise just 0.15% of the body, or about one hundred grams in total for the average person. Total fractions in this paragraph are amounts based on summing percentages from the article on chemical composition of the human body. Some diversity of opinion exist about the essential nature of various ultratrace elements in humans (and other mammals), even based on the same data. For example, whether chromium is essential in humans is debated. No Cr-containing biochemical has been purified. The United States and Japan designate chromium as an essential nutrient, but the European Food Safety Authority (EFSA), representing the European Union, reviewed the question in 2014 and does not agree.
=== Constituent assembly === One of Castillo's principal goals is to convene the constituent assembly to repeal and rewrite the Fujimori-era constitution. This measure is unlikely to pass in an opposition-controlled Congress. However, Free Peru and the Vice President have been collecting signatures to enact a constituent assembly via referendum. Likewise, the opposition has been gathering signatures against the proposal. Legal experts doubt whether these signatures will allow a constituent assembly to be held. Following the resignation of the Bellido cabinet, Prime Minister Mirtha Vásquez stated that changing the constitution is not a priority, despite it having been one of Castillo's main campaign promises. On 1 December 2021, Free Peru's spokesperson Waldemar Cerrón criticized a proposed Congressional bill which would require constitutional reforms to be "approved by Congress with an absolute majority of the legal number of members" to be submitted for referendum. This proposal would restrict the powers of the constituent assembly.
He developed a method for chemical modification of the GLA residues in 1982 and studied it using various metal ims and prothrombin fragments binding to phospholipid surfaces. These studies were recognized in Hiskey's National Heart, Lung and Blood Institute's Merit Award for the period 1986 to 1996. The study was extended to include various models containing tris-phosphates and peptides containing several GLA residues. Hiskey's interest in peptide synthesis resulted in membership on the Organization Committee of the American Peptide Symposium from 1978 to 1983, as well as from 1988 to 1990, and co-chairman of the 1982 Gordon Research Conference on the Chemistry and Biology of Peptides. Hiskey also received and accepted an invitation to visit Japan as a Japan Society for the Promotion of Science Fellow as a result of his work on peptide synthesis. Finally, the American Peptide Society presented Hiskey with the Society's Annual Award in June 1996. In that same year, Hiskey retired from the University of North Carolina as Alumni Distinguished Professor Emeritus.
== Production == Rabbit-skin glue is an animal glue created by prolonged boiling of animal connective tissue. Rabbit-skin glue can be bought in powder form, in little pellets, or in larger chunks. Preparation involves using the correct proportion of water to glue to achieve the correct consistency and strength. The mixture should be heated to just below the boiling point. Too much heat results in a product with reduced adhesive qualities. Manufacturers of rabbit, cow, and horse hide glues recommend dissolving at 60–63 °C (140–145 °F).
Benzodiazepines are usually administered orally; however, very occasionally lorazepam or diazepam may be given intravenously for the treatment of panic attacks. Because of their effectiveness, tolerability, and rapid onset of anxiolytic action, benzodiazepines are frequently used for the treatment of anxiety associated with panic disorder. However, there is disagreement among expert bodies regarding the long-term use of benzodiazepines for panic disorder. The views range from those holding benzodiazepines are not effective long-term and should be reserved for treatment-resistant cases to those holding they are as effective in the long term as selective serotonin reuptake inhibitors (SSRIs). American Psychiatric Association (APA) guidelines, published in January 2009, note that, in general, benzodiazepines are well tolerated, and their use for the initial treatment for panic disorder is strongly supported by numerous controlled trials. APA states that there is insufficient evidence to recommend any of the established panic disorder treatments over another. The choice of treatment between benzodiazepines, SSRIs, serotonin–norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants, and psychotherapy should be based on the patient's history, preference, and other individual characteristics. Selective serotonin reuptake inhibitors are likely to be the best choice of pharmacotherapy for many patients with panic disorder, but benzodiazepines are also often used, and some studies suggest that these medications are still used with greater frequency than the SSRIs.
Sources: en.wikipedia.org
==== Education ==== Duterte signed the Universal Access to Quality Tertiary Education Act in August 2017, providing free college education in all state universities and colleges nationwide. He signed a law establishing transnational higher education in the country, allowing foreign universities to offer degree programs in the Philippines in an effort to bring international quality standards and expertise into the country. He also signed medical scholarships for deserving students in state universities and colleges or partner private higher education institutions through the Doktor Para sa Bayan Act on December 23, 2020. Duterte approved in January 2021 a law institutionalizing the alternative learning system (ALS), providing free education to those out of school. In March 2022, he enacted a law granting inclusive education for learners with disabilities. On June 9, 2020, Duterte signed a law establishing the country's first National Academy of Sports in New Clark City, Capas, Tarlac.
Ari and Mac struggle to find time to be together with Mia and Chloe in the Bay. Mac tries to be supportive, but it becomes clear that there are unresolved issues between Ari and Mia. Kipa-Williams told Sarah Ellis of Inside Soap that Ari had no romantic intentions towards Mia, as he is happy with Mac, but then a sense of familiarity creeps in and being with Mia is "second nature" to Ari. Ari later invites Mia to a barbeque at the Parata house, but forgets to tell Mac, who learns about the event from Mia. Mac later sees Ari and Mia sharing a private moment together in the yard. Kipa-Williams said that Mia's presence has stirred up memories of the past that his character thought he had buried. While Samson commented that Mia does not want to get in the way of Ari's relationship and she has "no bad feelings" towards Mac. Ari later ends the relationship because of his unresolved feelings for Mia. Kipa-Williams told TV Week's Stephen Downie "After spending time in prison, Ari has decided to live by a new set of rules and tries to be as honest as possible. He loves Mia and Mac, which is why he needs to break up with Mac and figure out his feelings for Mia and what her being here means to him." In an interview with Susannah Alexander and Daniel Kilkelly of Digital Spy, Kipa-Williams expressed his disappointment about Mac and Ari's break up. He admitted that he was "really sad about it", as he enjoyed the bond he had formed with Weir and wanted their characters to become "a solid couple" similar to Ben Astoni (Rohan Nichol) and Maggie Astoni (Kestie Morassi).
=== Mechanism of action === The specific mechanisms by which drotrecogin exerts its effect on survival in patients with severe sepsis is not completely understood. In vitro data suggest that activated protein C exerts an antithrombotic effect by inhibiting factors Va and VIIIa, and that it has indirect profibrinolytic activity by inhibiting plasminogen activator inhibitor-1 (PAI-1). In vitro data also suggest that activated protein C may exert an anti-inflammatory effect by inhibiting tumor necrosis factor production, by blocking leukocyte adhesion to selectins, and by limiting the thrombin-induced inflammatory responses within the microvascular endothelium.
== Other uses == Chart Rulership or Chart Ruler, in astrology Comfort room, another name for a public toilet Consciousness raising, in social activism Continuing resolution, a type of appropriations legislation in the US Councillor, a title for a public servant, used in Australia and New Zealand Cree language (ISO 639 alpha-2 code CR) Critical reading, a skill measured by the Scholastic Aptitude Test (SAT) Crore, a number representing 10,000,000 in the Hindu-Arabic numeral system Cr$ or ₢, symbol for Brazilian cruzeiro
The daughter nuclide of a decay event may also be unstable (radioactive). In this case, it too will decay, producing radiation. The resulting second daughter nuclide may also be radioactive. This can lead to a sequence of several decay events called a decay chain (see this article for specific details of important natural decay chains). Eventually, a stable nuclide is produced. Any decay daughters that are the result of an alpha decay will also result in helium atoms being created. Some radionuclides may have several different paths of decay. For example, 35.94(6)% of bismuth-212 decays, through alpha-emission, to thallium-208 while 64.06(6)% of bismuth-212 decays, through beta-emission, to polonium-212. Both thallium-208 and polonium-212 are radioactive daughter products of bismuth-212, and both decay directly to stable lead-208.
Sources: en.wikipedia.org
== History == Effective pharmaceutical female sex-hormonal medications, including androgens, estrogens, and progestogens, first became available in the 1920s and 1930s, and might have been prescribed for transitions as early as the late 30s or 40s. The earliest report of hormone therapy in transgender women was published by Danish endocrinologist Christian Hamburger in 1953. One of his patients was Christine Jorgensen, who he had treated starting in 1950. Additional reports of hormone therapy in transgender women were published by Hamburger, the German-American endocrinologist Harry Benjamin, and other researchers in the mid-to-late 1960s. However, Benjamin had several hundred transgender patients under his care by the late 1950s, and had treated transgender women with hormone therapy as early as the late 1940s or early 1950s. In any case, Hamburger is said to be the first to treat transgender women with hormone therapy. One of the first transgender health clinics was opened in the mid-1960s at the Johns Hopkins School of Medicine. By 1981, there were almost 40 such centers. A review of the hormonal regimens of 20 of the centers was published that year. The first International Symposium on Gender Identity, chaired by Christopher John Dewhurst, was held in London in 1969, and the first medical textbook on transness, titled Transsexualism and Sex Reassignment and edited by Richard Green and John Money, was published by Johns Hopkins University Press in 1969. This textbook included a chapter on hormone therapy written by Christian Hamburger and Harry Benjamin.
== Name == The Socialist Republic of Bosnia and Herzegovina was formed during a meeting of the State Anti-fascist Council for the National Liberation of Bosnia and Herzegovina (ZAVNOBiH) in Mrkonjić Grad on 25 November 1943. In April 1945, its name was formalized as the Federated State of Bosnia and Herzegovina (Serbo-Croatian: Federalna Država Bosna i Hercegovina / Федерална Држава Босна и Херцеговина), a constituent unit of the Democratic Federal Yugoslavia. With DF Yugoslavia changing its name to the Federal People's Republic of Yugoslavia on 29 November 1945 as well as the promulgation of the 1946 Yugoslav Constitution two months later in January, its constituent units also changed their respective names. FS Bosnia and Herzegovina thus became known as the People's Republic of Bosnia and Herzegovina (Narodna Republika Bosna i Hercegovina / Народна Република Босна и Херцеговина). This constitutional system lasted until the 1963 Yugoslav Constitution. On 7 April 1963, Yugoslavia was reconstituted as the Socialist Federal Republic of Yugoslavia, and PR Bosnia and Herzegovina changed its name to the Socialist Republic of Bosnia and Herzegovina (Socijalistička Republika Bosna i Hercegovina / Социјалистичка Република Босна и Херцеговина). After independence on 1 March 1992, the country was renamed to the Republic of Bosnia and Herzegovina. Following the Dayton Agreement that was in force, it became simply a federated state known as Bosnia and Herzegovina in 1997.
=== Polymerase chain reaction === Graphene is reported to have enhanced PCR by increasing the yield of DNA product. Experiments revealed that graphene's thermal conductivity could be the main factor behind this result. Graphene yields DNA product equivalent to positive control with up to 65% reduction in PCR cycles.
== Receptors == The studies cited above lead to the eventual cloning of the human Formyl peptide receptor 1, a G protein coupled receptor that binds fMLF and other formylated oligopeptides to mediate their stimulatory actions on human and rabbit neutrophils. Subsequently, Formyl peptide receptor 2 and Formyl peptide receptor 3 were also cloned based on the similarities in their amino acid sequence to that of formyl peptide receptor 1. Formyl peptide receptors 2 and 3 have very different abilities to bind and respond to formylated oligopeptides including fMLF compared to formyl peptide receptor 1 and compared to each other and have very different functions than those of formyl peptide receptor 1.
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 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.