If you have been reading about prohibited list and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-07-03. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Analog of alpha-melanocyte-stimulating hormone |
| Primary receptor family | Melanocortin receptors MC1R through MC5R | Binding is not subtype-selective |
| Development period | 1980s | Synthesized during pigmentation and appetite research |
| Regulatory status | Not an approved medicine | No major regulator has authorized human use |
| Related compound | Afamelanotide | Linear analog studied for photoprotection |
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.
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.
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.
The peptide was developed during the 1980s by researchers investigating melanocortin signalling and skin pigmentation pathways. Early work focused on analogues of alpha-melanocyte-stimulating hormone that would resist enzymatic breakdown more effectively than the parent molecule. Melanotan-2 emerged from that programme as a shortened, cyclised variant. Reports describing its synthesis and receptor activity later appeared in the scientific literature. Commercial availability grew through unregulated channels rather than through pharmaceutical approval.
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.
The pelycosaurs are synapsids (more closely related to mammals) while the ctenosauriscids are archosaurs (closely related to crocodilians, pterosaurs and dinosaurs). Also, the spinosaurids had sail-like fins on their backs, when they were not closely related to either. Also, Acrocanthosaurus and Ouranosaurus, which are not closely related to either pelycosaurs, ctenosauriscids or spinosaurids, also had similar, but thicker, spines on their vertebrae. Noasaurus, Baryonyx, and Megaraptor, all unrelated, all had an enlarged hand claw that were originally thought to be placed on the foot, as in dromaeosaurs. A similarly modified claw (or in this case, finger) is on the hand of Iguanodon. The ornithopods had feet and beaks that resembled that of birds, but are only distantly related. Three groups of dinosaurs, the Tyrannosauridae, Ornithomimosauria, and the Troodontidae, all evolved an arctometatarsus, independently. Some placodonts (like Cyamodus, Psephoderma, Henodus and especially Placochelys) bear striking resemblance to sea turtles (and turtles in general) in terms of size, shell, beak, mostly toothless jaws, paddle-shaped limbs and possibly other adaptations for aquatic lifestyle.
=== August === 1 August – Stella Maris, the Rector of the University of St Andrews, is removed from the university's governing body over a letter she sent to students shortly after taking office in which she called for an immediate ceasefire in Gaza and referred to "genocidal attacks" made by the Israeli government. She will remain as Rector until October 2026, when her term ends. 4 August – A yellow weather warning is issued for heavy rain and strong winds in parts of Scotland, which is active until 9pm the following day. 6 August – Fiona Robertson, the chief executive of the Scottish Qualifications Authority, apologises after around 7,000 students who took their Higher examinations received blank emails instead of their results. The results were later sent by text message. 8 August – Cosla puts forward a new offer of a 3.6% increase for all grades of refuse workers in a bid to prevent strikes in 26 of Scotland's 32 council areas. The offer would represent a rise of £1,292 for the lowest paid, equivalent to a 5.63% increase. 8–12 August – The 82nd World Science Fiction Convention takes place in Glasgow. 9 August – 2024 United Kingdom riots: Police Scotland announces it is sending 120 of their officers to Belfast to help deal with ongoing riots in the city. 12 August – Unison, Unite and the GMB suspend planned strikes by refuse collectors following a new offer from Cosla. 13 August – Scotland's gender service for young people, based in Glasgow, announces it will stop accepting self-referrals.
== Side effects == Common side effects of anastrozole (≥10% incidence) include hot flashes, asthenia, arthritis, pain, arthralgia, hypertension, depression, nausea and vomiting, rash, osteoporosis, bone fractures, back pain, insomnia, headache, bone pain, peripheral edema, coughing, dyspnea, pharyngitis, and lymphedema. Serious but rare adverse effects (<0.1% incidence) include skin reactions such as lesions, ulcers, or blisters; allergic reactions with swelling of the face, lips, tongue, and/or throat that may cause difficulty swallowing or breathing; and abnormal liver function tests as well as hepatitis.
Gonadotropin preparations are drugs that mimic the physiological effects of gonadotropins, used therapeutically mainly as fertility medication for ovarian hyperstimulation and ovulation induction. For example, the so-called menotropins consist of LH and FSH extracted from human urine from menopausal women. There are also recombinant variants.
Congenital myopathy is a very broad term for any muscle disorder present at birth. This defect primarily affects skeletal muscle fibres and causes muscular weakness and/or hypotonia. Congenital myopathies account for one of the top neuromuscular disorders in the world today, comprising approximately 6 in 100,000 live births every year. As a whole, congenital myopathies can be broadly classified as follows:
Sources: en.wikipedia.org
==== 1400–1499 ==== Valuation Timetable (Scotland) Amendment (No.2) Order 1993 (S.I. 1993/1400) Nene Valley Light Railway (Transfer) Order 1993 (S.I. 1993/1402) Home-Grown Cereals Authority (Rate of Levy) Order 1993 (S.I. 1993/1405) Offshore Installations (Safety Zones) Order 1993 (S.I. 1993/1406) High Court and County Courts Jurisdiction (Amendment) Order 1993 (S.I. 1993/1407) Foreign Fields (Specification) Order 1993 (S.I. 1993/1408) Aeroplane Noise (Limitation on Operation of Aeroplanes) Regulations 1993 (S.I. 1993/1409) Fire Safety and Safety of Places of Sport Act 1987 (Commencement No. 7) Order 1993 (S.I. 1993/1411) Sports Grounds and Sporting Events (Designation) (Scotland) Amendment Order 1993 (S.I. 1993/1412) Food Protection (Emergency Prohibitions) (Paralytic Shellfish Poisoning) (No. 2) Order 1993 (S.I. 1993/1413) Removal, Storage and Disposal of Vehicles (Prescribed Sums and Charges etc.) (Amendment) (No. 2) Regulations 1993 (S.I. 1993/1415) Goods Vehicles (Operators' Licences) (Temporary Use in Great Britain) (Amendment) Regulations 1993 (S.I. 1993/1416) Hackney, Haringey and Islington (London Borough Boundaries) Order 1993 (S.I. 1993/1417) Non-Domestic Rating Act 1993 (Commencement No. 1) Order 1993 (S.I. 1993/1418) Suckler Cow Premium Regulations 1993 (S.I. 1993/1441) Feeding Stuffs (Amendment) Regulations 1993 (S.I. 1993/1442) East London Boroughs (London Borough Boundaries) Order 1993 (S.I. 1993/1443) East London Boroughs (London Borough Boundaries) (No. 2) Order 1993 (S.I. 1993/1444) City and London Borough Boundaries Order 1993 (S.I.
=== Treatment === Consumption of Amanita virosa is a medical emergency requiring hospitalization. There are four main categories of therapy for poisoning: preliminary medical care, supportive measures, specific treatments, and liver transplantation. Preliminary care consists of gastric decontamination with either activated carbon or gastric lavage. However, due to the delay between ingestion and the first symptoms of poisoning, it is commonplace for patients to arrive for treatment many hours after ingestion, potentially reducing the efficacy of these interventions. Supportive measures are directed towards treating the dehydration which results from fluid loss during the gastrointestinal phase of intoxication and correction of metabolic acidosis, hypoglycemia, electrolyte imbalances, and impaired coagulation. No definitive antidote for amatoxin poisoning is available, but some specific treatments have been shown to improve survivability. High-dose continuous intravenous penicillin G has been reported to be of benefit, though the exact mechanism is unknown, and trials with cephalosporins show promise. There is some evidence that intravenous silibinin, an extract from the blessed milk thistle (Silybum marianum), may be beneficial in reducing the effects of death cap poisoning. Silibinin prevents the uptake of amatoxins by hepatocytes, thereby protecting undamaged hepatic tissue; it also stimulates DNA-dependent RNA polymerases, leading to an increase in RNA synthesis. N-acetylcysteine has shown promise in combination with other therapies.
== Synthesis == Like all bacterial extracellular proteases thermolysin is first synthesised by the bacterium as a pre-proenzyme. Thermolysin is synthesized as a pre-proenzyme consisting of a signal peptide 28 amino acids long, a pro-peptide 204 amino acids long and the mature enzyme itself 316 amino acids in length. The signal peptide acts as a signal for translocation of pre-prothermolysin to the bacterial cytoplasmic membrane. In the periplasm pre-prothermolysin is then processed into prothermolysin by a signal peptidase. The prosequence then acts as a molecular chaperone and leads to autocleavage of the peptide bond linking pro and mature sequences. The mature protein is then secreted into the extracellular medium.
This barrier was extremely important in shaping the expansion of the United States in the colonial era. Much of the range's economy was historically based on logging and coal mining, which attracted many migrants who contributed to the genesis of a new cultural region. Though the decline of these industries was an economic detriment, many communities have pivoted to manufacturing and services. Tourism has also become increasingly prevalent: the mountains are home to the very popular Appalachian Trail, a 2,175-mile (3,500 km) hiking trail that runs from Mount Katahdin in Maine to Springer Mountain in Georgia. The International Appalachian Trail is an extension of this hiking trail into the Canadian portion of the Appalachian range in New Brunswick and Quebec.
Sources: en.wikipedia.org
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.
Afamelanotide is a linear analog that has received approval in some jurisdictions for a specific photoprotection indication. Melanotan II is cyclic and less selective across melanocortin receptors. The two are related but are not interchangeable in regulatory or clinical terms.
A compound that activates several receptor subtypes may produce effects beyond pigmentation. Selectivity influences which tissues respond and shapes the side-effect profile described in reports. Designing subtype-selective analogs is a stated goal of melanocortin research.
Only a small number of early-stage human studies have been reported, and most were limited in size and duration. No large late-stage program has established a general efficacy or safety profile. The evidence base is therefore thin compared with approved medicines.