This is a working overview of Melanotan II, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-09-03 and is reviewed periodically as new material appears.
Melanotan II is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its structure substitutes a lactam bridge between side chains to increase stability relative to the native hormone. The compound is also known by the shorthand MT-II and by several non-proprietary synonyms used in research catalogues. It is not an approved therapeutic product in any major jurisdiction; material sold under this name is typically offered as a laboratory reagent rather than as a medicine.
Activity is attributed to agonism at melanocortin receptors, particularly MC1R and MC4R. Activation of MC1R on melanocytes increases melanin synthesis, which underlies the reported tanning effect. MC4R engagement in the central nervous system is linked to appetite suppression and to effects on sexual arousal reported in early clinical studies. Those studies were small and were not designed to establish efficacy or long-term safety. Receptor selectivity among the melanocortin subtypes is not absolute, which complicates attribution of any effect to a single pathway.
Melanotan-2 is a synthetic cyclic heptapeptide designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous tridecapeptide that regulates pigment production. Two modifications distinguish it from the natural hormone: norleucine replaces methionine at the N-terminus, which limits oxidation, and a D-phenylalanine substitution raises receptor affinity. The ring is closed through an aspartate-lysine lactam bridge, giving the molecule a constrained conformation. The free base has a molecular mass near 1024 daltons, and commercial material is usually supplied as an acetate salt. It appears in the literature as a research peptide rather than an approved therapeutic agent.
Receptor studies place melanotan-2 among non-selective melanocortin agonists, binding MC1R, MC3R, MC4R and MC5R rather than a single subtype. Activation of MC1R on cutaneous melanocytes raises tyrosinase activity and shifts pigment synthesis toward eumelanin, which is darker and more photostable than pheomelanin. Central receptors, particularly MC4R, are associated with appetite suppression and with reported effects on sexual function. Because subtype selectivity is low, the same molecule engages pigment, metabolic and vascular pathways at once, and this breadth is a common explanation offered for the range of adverse events described in user reports.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Analogue of alpha-melanocyte-stimulating hormone |
| Common synonyms | MT-II; melanotan 2 | No internationally accepted non-proprietary name |
| Typical presentation | Lyophilised powder in a sealed vial | Often supplied alongside a separate diluent |
| Regulatory status | Unapproved therapeutic substance | Customs seizure reported in several jurisdictions |
| Reported route in use | Subcutaneous injection | Self-administered outside clinical settings |
Melanotan II is a synthetic cyclic heptapeptide that acts as an agonist at melanocortin receptors. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous peptide involved in pigment production. The analogue carries a lactam bridge that constrains the ring and slows enzymatic breakdown relative to the native hormone. In research literature it appears under several abbreviations, and naming conventions are not fully standardized. Published descriptions usually place it within the broader melanocortin agonist family.
Receptor binding at MC1R on melanocytes raises intracellular cyclic AMP and increases expression of tyrosinase and related enzymes. The downstream result is greater synthesis of eumelanin, the dark pigment, without ultraviolet exposure acting as the trigger. The compound is not selective, however, and also engages MC3R, MC4R and MC5R, which are expressed in the central nervous system and elsewhere. That lack of selectivity is the explanation usually offered for effects reported outside pigmentation, including appetite suppression and nausea. Selectivity remains a central theme in comparative studies of related peptides.
The compound was developed in the late 1980s and 1990s by academic researchers investigating photoprotection. The rationale held that stimulating melanin production might reduce ultraviolet damage to skin and lower skin cancer risk. Early work examined receptor binding, pigment response, and short-term tolerability in small studies. That program did not produce an approved drug, and formal development stalled after early-phase trials. Whether induced pigmentation confers meaningful photoprotection remains an open question.
Outside regulated medicine, melanotan II circulates through online vendors as a research chemical, often marketed for tanning. Products sold this way vary widely in purity, concentration, and labeling accuracy, and independent testing has documented discrepancies. Published reports describe both pigment effects and adverse reactions, including nausea, flushing, and darkening of existing moles. Long-term safety data are sparse, and no large controlled trial has established a risk profile. Questions about cumulative effects on melanocytes remain unresolved in the literature.
==== 11beta-hydroxysteroid dehydrogenases ==== Cortisol is metabolized reversibly to cortisone by the 11-beta hydroxysteroid dehydrogenase system (11-beta HSD), which consists of two enzymes: 11-beta HSD1 and 11-beta HSD2. The metabolism of cortisol to cortisone involves oxidation of the hydroxyl group at the 11-beta position.
=== Extraction methods === Ossein can be isolated by treating bones with hydrochloric acid, which dissolves the inorganic matrix (calcium phosphate and calcium carbonate). The process was discovered no later than 15th century but only really spread in the 18th century, after Glauber's publications. The resulting liquor carrying calcium chloride and phosphoric acid may then be treated with calcium hydroxide to recover dicalcium phosphate for fertilizers or animal feed supplement. However, the most popular technique of treating the bone meal is steaming or boiling. This process requires no acid but much more energy and may also produce tricalcium phosphate. As an alternative, the deproteinized bone residue left after the removal of ossein can be used to produce bone ash for the manufacture of bone china.
=== Cystinosis === Mutations in CTNS gene can result in cystinosis. Cystinosis is a type of lysosomal transport disorder, a subset of lysosomal storage disorders. Variation in the encoded cystinosin protein results in an inhibition or loss in its ability to transport cystine out of the lysosome. Cystine molecules accumulate and form crystals within the lysosome, impairing its function.
Sources: en.wikipedia.org
Endotoxins are negatively charged, and will bind to an anion exchanger. If the target substance is not also negatively charged, it will pass through the column before the endotoxin, and an effective separation can be achieved. This method is sometimes used in the purification of albumins (details follow). Ligands of known affinity to endotoxins can be coupled to an anion exchange system to increase its endotoxin binding strength and further improve the purity of the final product. Typical examples of endotoxin binding ligands include histamine, nitrogen-containing heterocyclic compounds, and polymyxin B. However, polymyxin B is known to induce production of interleukin-1, an exogenous pyrogen, and thus must be shown to be absent in the final product if used. Example of using anion exchange chromatography to purify albumin: 2% of the endotoxin does not bind to the column. However, this 2% washes out before the albumin peak, and can thus be removed simply by starting collection after this 2% has washed out. 10% of the endotoxin that does bind to the column (9.8% of the original total) will eventually wash out after the albumin peak. This can be prevented from entering the final product by stopping collection before this happens. The remaining 90% of the bound endotoxin (88.2% of the original total) must be cleaned off the column using NaOH An alternative to anion exchange is cation exchange chromatography, in which positively charged solutes bind to the solid chromatographic media. In this method, the target binds to the column instead of the endotoxin.
==== Yellow armbands ==== Following Adam Ramanauskas's personal battle with cancer, a "Clash for Cancer" match against Melbourne was launched in 2006. This was a joint venture between Essendon and the Cancer Council of Victoria to raise funds for the organisation. Despite a formal request to the AFL being denied, players wore yellow armbands for the match, which resulted in the club being fined $20,000. In 2007, the AFL agreed to allow yellow armbands to be incorporated into the left sleeve of the jumper. The 'Clash for Cancer' match against Melbourne has become an annual event, repeated in subsequent seasons, though in 2012, 2013, 2014 and 2016, Hawthorn (twice), the Sydney Swans and Brisbane Lions were the opponents in those respective seasons instead of Melbourne. In 2009, the jumpers were auctioned along with yellow boots worn by some players during the match.
=== Government and NGO reports === National Drug Threat Assessment 2009 from the United States Department of Justice War On Drugs: Legislation in the 108th Congress and Related Developments, a 2003 report from the Congressional Research Service via the State Department website The Report of the Canadian Government Commission of Inquiry into the Non-Medical Use of Drugs – 1972 Drug Enforcement Administration (2017), Drugs of abuse: A DEA resource guide (PDF) (2017 ed.), Washington, D.C.: Author, archived from the original (PDF) on December 3, 2016, retrieved January 23, 2018 Revealing the missing link to Climate Justice: Drug Policy, a 2023 report from the International Coalition on Drug Policy Reform and Environmental Justice
Sources: en.wikipedia.org
== Terminology == Tendinitis is a very common, but misleading term. By definition, the suffix "-itis" means "inflammation of". Inflammation is the body's local response to tissue damage which involves red blood cells, white blood cells, blood proteins with dilation of blood vessels around the site of injury. Tendons are relatively avascular. Corticosteroids are drugs that reduce inflammation. Corticosteroids can be useful to relieve chronic tendinopathy pain, improve function, and reduce swelling in the short term. However, there is a greater risk of long-term recurrence. They are typically injected along with a small amount of a numbing drug called lidocaine. Research shows that tendons are weaker following corticosteroid injections. Tendinitis is still a very common diagnosis, though research increasingly documents that what is thought to be tendinitis is usually tendinosis. Anatomically close but separate conditions are:
== Nitrogen-14 == Nitrogen-14 makes up the clear majority of natural nitrogen, about 99.62%, and is responsible for the Earth's stable atmosphere. Nitrogen-14 is one of the very few stable nuclides with both an odd number of protons and of neutrons (seven each) and is the only one to make up a majority of its element. Unpaired protons or neutrons contribute a half-integer nuclear spin, which in this case is a spin 1/2 orbital, giving the nucleus a total magnetic spin of one (as the spins prefer to align). The original source of nitrogen-14 and nitrogen-15 in the Universe is believed to be stellar nucleosynthesis, where they are produced as part of the CNO cycle. Nitrogen-14 is the source of naturally occurring, radioactive, carbon-14. Some kinds of cosmic radiation cause a nuclear reaction with nitrogen-14 in the upper atmosphere of the Earth, creating carbon-14, which decays back to nitrogen-14 with a half-life of 5700 years.
== Italian Republic == Southern monarchist Enrico De Nicola became the provisional head of the Italian Republic. On 12 July 1946 De Gasperi formed the second De Gasperi government, becoming the first Prime Minister of the Italian Republic. The governmental structure still rested on agreement between the major anti-fascist parties. Left-wing parties downsized in favor of the Christian Democrats. The Communists and Socialists went from 8 to 6 ministries, whose ministers were Christian Democrats: Sicilian Mario Scelba became Minister of the Interior, Communist Emilio Sereni was Minister of Public Works, while Gullo, Agriculture minister since 1943, became Minister of Justice; his replacement was Antonio Segni (CD), a Sardinian landowner and future President.
In 2023, Google DeepMind introduced GNoME, a method to propose candidate inorganic crystal structures for computational screening and experimental synthesis in material science. Other material science methods include MatterGen, CDVAE, and CrystalFlow.
Sources: en.wikipedia.org
No. No major regulatory agency has granted a marketing authorisation for melanotan II as a medicine. Products sold under this name are generally presented as laboratory reagents and are not subject to the batch-release testing applied to approved drugs.
It was developed in the 1980s by researchers investigating analogues of alpha-melanocyte-stimulating hormone for pigmentation and related endpoints. Early work included small human studies during the 1990s. Development did not progress to licensing, and the compound remained a research and grey-market item.
Peptides are prone to truncation, oxidation and aggregation during synthesis and handling. Without independent testing, a buyer cannot confirm the identity or the content of a vial. Analytical surveys of unapproved peptide products have repeatedly found discrepancies between label claims and measured composition.
No regulatory agency has authorised melanotan-2 as a medicine for any indication. It circulates mainly as a research chemical or through unregulated channels. As a result, identity, purity and content are not independently guaranteed.