Everything below concerns prohibited list. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-02-05. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C or below | For the lyophilised powder, desiccated |
| Storage form | Sealed vial, protected from light | Amber glass or foil-wrapped containers |
| Reconstituted stability | Short, refrigerate | Degradation accelerates in solution |
| Typical analytical method | Reversed-phase HPLC with mass spectrometry | Purity assessment plus identity confirmation |
| Common synonyms | Melanotan II, MT-II | Also written melanotan-2 |
Identification in laboratories relies on reversed-phase liquid chromatography coupled with tandem mass spectrometry, with product-ion spectra compared against a certified reference standard. High-resolution mass spectrometry supplies accurate mass confirmation, and peptide mapping after enzymatic digestion separates melanotan II from closely related analogues. Quantitation of seized material is complicated by unknown counter-ions and residual trifluoroacetate left from purification. Immunoassays raised against alpha-melanocyte-stimulating hormone can cross-react, so chromatographic confirmation is normally required. Urinary detection windows are short, and reported limits of detection differ substantially between laboratories.
Melanotan II holds no marketing authorisation from the Food and Drug Administration, the European Medicines Agency, the UK Medicines and Healthcare products Regulatory Agency or Australia's Therapeutic Goods Administration. Products sold under that name are treated as unapproved new drugs, and their sale or import is prohibited in several jurisdictions. Other countries classify the peptide as a prescription-only medicine or place it among controlled substances, so the legal position changes with the destination market. No pharmacopoeial monograph supplies an official specification, because the material is not a licensed pharmaceutical. Consequently, products offered online are not manufactured to a shared public standard.
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.
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.
=== Modern method === Deep-frozen stomachs are milled and put into an enzyme-extracting solution. The crude rennet extract is then activated by adding acid; the enzymes in the stomach are produced in an inactive form and are activated by the stomach acid. The acid is then neutralized and the rennet extract is filtered in several stages and concentrated until reaching a typical potency of about 1:15,000; meaning 1 g of extract can coagulate 15 kg of milk. One kilogram of rennet extract has about 0.7 g of active enzymes – the rest is water and salt and sometimes sodium benzoate (E211), 0.5%–1.0% for preservation. Typically, 1 kg of cheese contains about 0.3 mg of rennet enzymes.
9-Carboxymethoxymethylguanine (CMMG) is a compound which is known as the principal metabolite of the antiviral medication aciclovir (and its prodrug valaciclovir), and has been suggested as the causative agent in the neuropsychiatric side effects sometimes associated with these medications. These are mainly suffered by patients with kidney failure or otherwise decreased kidney function, and can include psychotic reactions, hallucinations, and rarely more complex disorders such as Cotard delusion. Patients suffering these symptoms following aciclovir treatment were found to have much higher levels of CMMG than normal, and since this is the first time Cotard delusion has been linked to a drug as a side effect, this discovery may be useful in the study of Cotard delusion and its treatment.
Lately Policy and Campaigns Director, United Kingdom Homecare Association. For services to Domiciliary Care. Andrew David Arbuckle. Trustee and Fundraiser, Royal Scottish Agricultural Benevolent Institution. For services to Farming and to the community in Fife. Sarah Elizabeth Armitage. Chair of Trustees, Embark Federation. For services to Education. Paul Robert Arnold. Deputy Chief Executive and Chief Operating Officer, Information Commissioner's Office. For services to Regulation and to Equality, Diversity and Inclusion. Keith Alan Ashcroft. Lately Area Director, Environment Agency. For services to the Environment. Simon Edward Ayers. Chief Executive Officer, TrustMark. For services to Consumer Protection. Jannella Baker. Training Officer, Berkshire Search and Rescue Dogs, Lowland Rescue. For services to Search and Rescue. David Martin James Ball. For services to the community in East Anglia. Sarah Pamela Ballantine. For Charitable Fundraising in Northern Ireland. Tajinder Kaur Banwait. Founder, Urban Apothecary London. For services to Business and to the Beauty Industry. Timothy Paul Barnes. Chair, St George's Garrison Church Trust. For services to the community in the Royal Borough of Greenwich, London. Dr. Catherine Emma Baxter. University Secretary, Harper Adams University. For services to Higher Education. Gina Beard. Lead Cancer Nurse, Hywel Dda University Health Board. For services to Cancer Nursing. Robert Duncan Beaumont. Lately Governor, Ravenscliffe High School and Sports College, Halifax.
=== Properties === Detrital zircons usually retain similar properties as their parent igneous rocks, such as age, rough size and mineral chemistry. However, the composition of detrital zircons is not entirely controlled by the crystallization of the zircon mineral. In fact, many of them are modified by later processes in the sedimentary cycle. Depending on the degree of physical sorting, mechanical abrasion and dissolution, a detrital zircon grain may lose some of its inherent features and gain some over-printed properties like rounded shape and smaller size. On a larger scale, two or more tribes of detrital zircons from different origins may deposit within the same sedimentary basin. This gives rise to a natural complexity of associating detrital zircon populations and their sources. Zircon is a strong tool for uranium-lead age determination because of its inherent properties:
=== Distribution === With oral CPA, there is a probable distribution phase of CPA into tissues which lasts about 12 hours and has a half-life of 3 hours. CPA is very lipophilic, and it is sequestered into fat, which provides a depot effect. The volume of distribution of CPA is 20.6 ± 3.5 L/kg. CPA crosses the blood–brain barrier, which is evidenced by the suppression of gonadotropin secretion that is observed during therapy with it (the site of action of this effect being the pituitary gland, a part of the brain). In terms of plasma protein binding, CPA does not bind to SHBG or corticosteroid-binding globulin and is instead bound exclusively to albumin (93%), with the remainder (7%) circulating free or unbound. The affinity of CPA for SHBG is very low at about 0.006% of that of testosterone or DHT.
Sources: en.wikipedia.org
Soldiers were expected to carry their grain rations and cooking utensils in addition to their weaponry, with their backpacks potentially weighing as much as eighty pounds (36 kg). Without the hindrance of oxen and carts, this enabled Macedonian armies to move faster than their opponents. The grain provided to Macedonian soldiers would be wheat, barley, or millet, which were available throughout Asia and could be stored indefinitely when dried. The soldiers would use grinding mills carried by servants to turn the grain into flour, which could then be made into bread, biscuits, and porridge. They also ate various kinds of dried fruits such as dates and figs, which were readily available throughout much of Asia. Whenever possible, they would eat dried meat, salted fish, and shellfish. In ancient China, soldiers of the Han dynasty ate primarily millet and other grains such as wheat, rice, sorghum, etc. Grains could be eaten as a porridge, boiled, made into a bread or flatbread, smashed and fried in a manner similar to modern fried rice and fried noodles, etc. According to Zhao Chongguo, a military commander of the Han dynasty who served in the first century BC, a force of 10,281 men required 27,363 hu of grain and 308 hu of salt each month, requiring a convoy of 1,500 carts for transport. One hu is equivalent to 19.968 liters, meaning that each soldier would have required 51.9 liters of grain and 0.6 liters of salt per month. Another document at Juyan suggests 3.2 hu, or 63.8 liters, of grain.
== History == Shotgun proteomics arose from the difficulties of using previous technologies to separate complex mixtures. In 1975, two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) was described by O’Farrell and Klose with the ability to resolve complex protein mixtures. The development of matrix-assisted laser desorption ionization (MALDI), electrospray ionization (ESI), and database searching continued to grow the field of proteomics. However these methods still had difficulty identifying and separating low-abundance proteins, aberrant proteins, and membrane proteins. Shotgun proteomics emerged as a method that could resolve even these proteins.
=== Extramitochondrial === At high glucose levels, glycolysis takes place rapidly, thus increasing the amount of citrate produced from the citric acid cycle. This citrate is then exported to other organelles outside the mitochondria to be broken into acetyl-CoA and oxaloacetate by the enzyme ATP citrate lyase (ACL). This principal reaction is coupled with the hydrolysis of ATP. At low glucose levels CoA is acetylated using acetate by acetyl-CoA synthetase (ACS), also coupled with ATP hydrolysis. Ethanol also serves as a carbon source for acetylation of CoA utilizing the enzyme alcohol dehydrogenase. Degradation of branched-chain ketogenic amino acids such as valine, leucine, and isoleucine occurs. These amino acids are converted to α-ketoacids by transamination and eventually to isovaleryl-CoA through oxidative decarboxylation by an α-ketoacid dehydrogenase complex. Isovaleryl-CoA undergoes dehydrogenation, carboxylation and hydration to form another CoA-derivative intermediate before it is cleaved into acetyl-CoA and acetoacetate. Additionally, malonyl-CoA decarboxylase (MCD), present in the cytosol, contributes to the extramitochondrial acetyl-CoA pool by converting malonyl-CoA into acetyl-CoA.
Wilson told the British House of Commons in January 1966 that he would not enter any kind of dialogue with the post-UDI Rhodesian "illegal regime" until it gave up its claim of independence, but by mid-1966 British and Rhodesian civil servants were holding "talks about talks" in London and Salisbury. By November that year, Wilson had agreed to negotiate personally with Smith. The two Prime Ministers unsuccessfully attempted to settle aboard HMS Tiger in December 1966 and HMS Fearless in October 1968. After the Conservatives returned to power in Britain in 1970, provisional agreement was reached in November 1971 between the Rhodesian government and a British team headed by Douglas-Home (who was Foreign Secretary under Prime Minister Edward Heath), and in early 1972 a Royal Commission chaired by Lord Pearce travelled to Rhodesia to investigate how acceptable the proposals were to majority opinion. After extensive consultation, the commission reported that while whites, coloureds and Asians were largely in favour of the presented terms, most blacks rejected them. The deal was therefore shelved by the British government. The Rhodesian Bush War, a guerrilla conflict pitting the Rhodesian Security Forces against the Zimbabwe African National Liberation Army (ZANLA) and the Zimbabwe People's Revolutionary Army (ZIPRA), the respective armed wings of ZANU and ZAPU, began in earnest in December 1972, when ZANLA attacked Altena and Whistlefield Farms in north-eastern Rhodesia.
=== Gestational breast hypertrophy === This same effect can also occur at the onset of pregnancy or between the 16th to 20th week of gestation. When the swelling in the connective tissue occurs after birth, it can negatively impact long term milk supply. The swelling increases with each subsequent pregnancy. The extremely rapid growth of the breasts can result in intense heat. The woman's breasts can generate extraordinary discomfort, turning feverish, red, itchy, and even causing the skin to peel. The swelling can suppress the milk supply, pinching off the milk ducts, and leading to mastitis. Gestational gigantomastia is estimated to occur in 1 out of every 28,000 to 100,000 pregnancies. Breast size in women with gestational breast hypertrophy typically reverts to approximately pre-pregnancy size or near it after pregnancy and cessation of breastfeeding. This is not always the case however and in some only partial reduction in breast size may occur, necessitating surgical breast reduction.
Sources: en.wikipedia.org
ASH New Zealand stated that earlier increases in youth vaping occurred during a period before vaping products were comprehensively regulated in late 2020. In Canada reported that past-30-day vaping among youth aged 12–17 declined from 13.2% in 2019 to 7.2% in 2023. Health Canada also set a target of reducing vaping prevalence among those aged 12 to 17 to below 10% by 2025.
The United States and Iran reached a final agreed-upon text for a peace deal to end the war on 12 June 2026. On 17 June, Donald Trump and Iranian president Masoud Pezeshkian signed remotely the memorandum of understanding to end the war, which established a 60-day extension of the ceasefire to negotiate the final terms of a deal.
=== Belgium === In Belgium, a clinical biologist (biologiste clinique) is a medical doctor or pharmacist who has completed a five-year postgraduate specialization in clinical biology (biologie clinique). This specialization is regulated by the Belgian Ministry of Public Health, and clinical biologists work in both hospital and private laboratories. Their training includes rotations in different laboratory disciplines, including hematology, microbiology, and clinical chemistry. They are responsible for interpreting laboratory results, ensuring quality control, and advising clinicians on diagnostic strategies.
==== Absorption ==== The oral bioavailability of atenolol is approximately 50 to 60%. The absorption of atenolol with oral administration is rapid and consistent but is incomplete. About 50% of an oral dose of atenolol is absorbed from the intestines, with the rest excreted in feces. Maximal concentrations of atenolol occur 2 to 4 hours following an oral dose, whereas peak concentrations occur within 5 minutes with intravenous administration. The pharmacokinetic profile of atenolol results in it having relatively consistent plasma drug levels with about 4-fold variation between individuals.
== Cross-Linked Enzyme Aggregates (CLEAs) == The use of cross-linked enzyme crystals (CLECs) as industrial biocatalysts was pioneered by Altus Biologics in the 1990s. CLECs proved to be significantly more stable to denaturation by heat, organic solvents and proteolysis than the corresponding soluble enzyme or lyophilized (freeze-dried) powder. CLECs are robust, highly active immobilized enzymes of controllable particle size, varying from 1 to 100 micrometer. Their operational stability and ease of recycling, coupled with their high catalyst and volumetric productivities, renders them ideally suited for industrial biotransformations. However, CLECs have an inherent disadvantage: enzyme crystallization is a laborious procedure requiring enzyme of high purity, which translates to prohibitively high costs. The more recently developed cross-linked enzyme aggregates (CLEAs), on the other hand, are produced by simple precipitation of the enzyme from aqueous solution, as physical aggregates of protein molecules, by the addition of salts, or water miscible organic solvents or non-ionic polymers. The physical aggregates are held together by covalent bonding without perturbation of their tertiary structure, that is without denaturation. Subsequent cross-linking of these physical aggregates renders them permanently insoluble while maintaining their pre-organized superstructure, and, hence their catalytic activity. This discovery led to the development of a new family of immobilized enzymes: cross-linked enzyme aggregates (CLEAs).
Sources: en.wikipedia.org
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.
Reversed-phase liquid chromatography assesses purity, while mass spectrometry confirms molecular mass and detects sequence errors. Amino acid analysis and peptide mapping add structural detail. These techniques are complementary rather than interchangeable.
It is listed as a prohibited peptide hormone by the World Anti-Doping Agency. No medicines regulator has approved it for human use. Import and sale rules vary by country.
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.