Everything below concerns prohibited list. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Cyclic heptapeptide, C-terminally amidated |
| Approximate molecular mass | 1024 Da | Monoisotopic mass of the free peptide |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility class | Soluble in water and polar solvents | Also dissolves in neutral aqueous buffer |
| Common synonyms | Melanotan II, MT-II, MT-2 | Described as a melanocortin agonist in early literature |
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, 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.
It is removed under harsh conditions using HBr in acetic acid, or milder conditions of catalytic hydrogenation. This methodology was first used in the synthesis of oligopeptides by Zervas and Max Bergmann in 1932. Hence, this became known as the Bergmann-Zervas synthesis, which was characterized "epoch-making" and helped establish synthetic peptide chemistry as a distinct field. It constituted the first useful lab method for controlled peptide synthesis, enabling the synthesis of previously unattainable peptides with reactive side-chains, while Z-protected amino acids are also prevented from undergoing racemization. The use of the Bergmann-Zervas method remained the standard practice in peptide chemistry for two full decades after its publication, superseded by newer methods (such as the Boc protecting group) in the early 1950s. Nowadays, while it has been used periodically for α-amine protection, it is much more commonly used for side chain protection.
Alcohol: It has been reported that combined use of alcohol and kava extract can have additive sedative effects. Kava has been shown to create additive cognitive impairments when taken with alcohol, compared to taking placebo and alcohol alone. Anxiolytics (CNS depressants such as benzodiazepines and barbiturates): Kava may have potential additive CNS depressant effects (such as sedation and anxiolytic effects) with benzodiazepines and barbiturates. Kava taken in combination with alprazolam can cause a semicomatose state in humans. Dopamine agonist such as levodopa: One of levodopa's chronic side effects in Parkinson's patients is the "on-off phenomenon" of motor fluctuations - periods of oscillations between "on", where the patient experiences symptomatic relief, and "off", where the therapeutic effect wears off early. When levodopa and kava are taken together, it has been shown that there is an increased frequency of this "on-off phenomenon".
== Medical uses == Ertapenem is indicated for the treatment of intra-abdominal infections, community-acquired pneumonia, pelvic infections, and diabetic foot infections, with bacteria that are susceptible to this drug, or expected to be so. It can also be used to prevent infections after colorectal surgery. In the United States it is also indicated for the treatment of complicated urinary tract infections including pyelonephritis. It is a potential effective alternative treatment for ceftriaxone-resistant gonorrhoea. It is given as an intravenous infusion or intramuscular injection. The drug is not approved for children under three months of age.
=== Early onset === Early onset is seen in newborns. The symptoms of a urea cycle disorder are often not seen until the child is at home and may not be recognized in a timely manner by the family and primary care physician. Symptoms in young children with hyperammonemia are non-specific: not willing to eat, problems with breathing, body temperature, seizures, unusual body movements (twitches) and somnolence. As ammonia build up continues, symptoms progress from somnolence to lethargy potentially ending in a coma. Abnormal posturing (uncontrolled movement) and encephalopathy (brain damage) are often related to the degree of central nervous system swelling and pressure upon the brainstem. About 50% of neonates with severe hyperammonemia have seizures.
==== Congress of South African Students ==== Accounts of the uprising typically accord a central role to black young adults – known in the anti-apartheid movement as "young lions" or "comrades" – who became the "shock troops" of the revolt. Their largest and most prominent organisational base was COSAS, another UDF affiliate that was founded in 1979, with a local branch in Vaal from March 1980. COSAS apparently played an important role in politicising the youth of Vaal, including by encouraging them to support the VCA, and many of the most militant participants in the uprising were formally or informally affiliated to COSAS.
Sources: en.wikipedia.org
=== Outer membrane vesicle === Outer membrane vesicles (OMVs) are naturally immunogenic and can be manipulated to produce potent vaccines. The best known OMV vaccines are those developed for serotype B meningococcal disease.
Insectivores which fed on unsupplemented invertebrates have been found to suffer from vitamin A deficiencies, and a study of panther chameleons (Furcifer pardalis) found vitamin A deficiency shortened life spans and reduced reproduction rates. Turkestan cockroaches are rich in vitamin B12.
On September 18, during the second game of doubleheader against their division rivals, the Los Angeles Dodgers, with the Rockies down to their last out, trailing by a run, Helton hit a clutch two-run walk-off home run off Dodgers closer Takashi Saito, producing what may have been the most emotional moment of the regular season, turning what seemed like an imminent loss into an improbable victory, and helping propel the team toward an October run. The miracle home run kept the Rockies alive in the bid to win the wild card or perhaps even NL West title. The Rockies eventually clinched the NL wild card, in a 9–8 extra innings victory over the Padres in a wild card tie-breaker game, allowing Helton to appear in the playoffs for the first time in his career. The Rockies kept their run going into October. Having never won a playoff series in their history, the Rockies went on a rampage through the National League, winning every game they played in the NL playoffs, as they marched into the World Series. The team's first playoff opponent was the Philadelphia Phillies, who the Rockies swept in three games in the NL Division Series. Helton hit a triple on the first postseason pitch he ever faced, during the opening game of the NLDS in Philadelphia. In the second round of the playoffs, the Rockies faced the Arizona Diamondbacks, who they swept in four games of the NL Championship Series, sending the Rockies on their first trip to the World Series in franchise history.
== Medical uses == Several treatment guidelines recommend adding ezetimibe in select high-risk persons in whom LDL goals cannot be achieved by maximally tolerated statin alone. Adding ezetimibe to statin treatment of high blood cholesterol has no effect on overall mortality or cardiovascular mortality, although it significantly reduces the risk of myocardial infarction and stroke. Combining ezetimibe with simvastatin had no effect on overall mortality but did lower the risk of heart attack or stroke in people with prior heart attack. Initiation of ezetimibe along with high-intensity statin therapy at the time of an acute coronary syndrome (ACS) event was associated with significantly better cholesterol reduction at day 7, 1-month, 3-months, and 1-year post-ACS event; which translated into significantly lower recurrent cardiovascular events (death from any cause, major ACS, non-fatal stroke, non-fatal myocardial infarction, and ischemic stroke) post the index event of ACS. Ezetimibe is indicated in the United States as an add-on to dietary measures to reduce levels of certain lipids in people with:
Sources: en.wikipedia.org
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).
=== Prisoner exchange === Following the ceasefire on 18 July 2025, a prisoner exchange attempt on 20 July 2025 in the Umm al-Zaytoun town failed after a shelling from northern Suwayda, according to the Syrian Observatory for Human Rights.
== Mythological origins == In Greek mythology, the centaur Chiron was a "Wounded Healer", after being poisoned with an incurable wound by one of Hercules's arrows. Jung mentioned the Chiron myth "wounding by one's own arrow means, first of all, the state of introversion"; For Jung, "a good half of every treatment that probes at all deeply consists in the doctor's examining himself... it is his own hurt that gives a measure of his power to heal. This, and nothing else, is the meaning of the Greek myth of the wounded physician." Jung felt that depth psychology can be potentially dangerous, because the analyst is vulnerable to being infected by his analysis by having his own wounds reopened. To avoid this, the analyst must have an ongoing relationship with the unconscious, otherwise he or she could identify with the "healer archetype", and create an inflated ego. Withdrawal of both projections may however ultimately activate the powers of the inner healer in the patients themselves. Jung’s closest colleague, Marie Louise Von Franz, said “the wounded healer IS the archetype of the Self [our wholeness, the God within] and is at the bottom of all genuine healing procedures.” Jungians warn of the dangers of inflation and splitting in the helping professions, involving projection of the 'wounded' pole of the archetype onto the patient alone, with the analyst safely separated off as 'healer'.
Blood typing is typically performed using serologic methods. The antigens on a person's red blood cells, which determine their blood type, are identified using reagents that contain antibodies, called antisera. When the antibodies bind to red blood cells that express the corresponding antigen, they cause red blood cells to clump together (agglutinate), which can be identified visually. The person's blood group antibodies can also be identified by adding plasma to cells that express the corresponding antigen and observing the agglutination reactions. Other serologic methods used in transfusion medicine include crossmatching and the direct and indirect antiglobulin tests. Crossmatching is performed before a blood transfusion to ensure that the donor blood is compatible. It involves adding the recipient's plasma to the donor blood cells and observing for agglutination reactions. The direct antiglobulin test is performed to detect if antibodies are bound to red blood cells inside the person's body, which is abnormal and can occur in conditions like autoimmune hemolytic anemia, hemolytic disease of the newborn and transfusion reactions. The indirect antiglobulin test is used to screen for antibodies that could cause transfusion reactions and identify certain blood group antigens.
=== April === 2 April – The Birmingham Walkathon returns to the city for the first time since 2013. The event, originally organised by Birmingham radio station BRMB, is organised for its 2023 staging by former BRMB director David Bagley and charity Help Harry Help Others. 3 April – NHS England launches its spring booster campaign, which will see around five million people, including those aged over 75 or classed as clinically vulnerable, receive a COVID-19 booster vaccine. The National Education Union announces two further strike dates in England on 27 April and 2 May, stating that the offer from the pay UK government is unacceptable, not fully funded, and does not address a shortage of teachers. Environment Minister Therese Coffey confirms government plans to ban wet wipes containing plastic in England as a means of helping to tackle water pollution. The new England women's national football team kit is unveiled, and it is confirmed they will wear blue shorts at the 2023 World Cup. The change has been made amid period concerns. 4 April – Members of the Association of School and College Leaders overwhelmingly reject the UK government's 4.3% pay offer for teachers in England. 5 April – Twenty one people are convicted over the largest child sex abuse case ever investigated by West Midlands Police. The National Association of Head Teachers becomes the third teaching union to reject the UK government's 4.3% pay offer for teachers in England.
Sources: en.wikipedia.org
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.
Afamelanotide is the linear analogue [Nle4-D-Phe7]-alpha-MSH, sometimes called melanotan I, while melanotan II is cyclic and carries three further substitutions. The two are distinct molecules and are not interchangeable in analytical testing.
Binding to the four melanocortin receptor subtypes is well documented in vitro. The relative contribution of each subtype to whole-body effects in humans is far less certain.
The lyophilised solid is best kept cold, dry and dark, typically at minus twenty degrees Celsius. Moisture and repeated warming cycles are the main causes of degradation. Solutions prepared from the powder are less stable and are normally used quickly.