If you have been reading about alpha-MSH 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 2026-05-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Melanocortin receptors comprise five subtypes with distinct tissue distributions and functions. Melanotan-2 is described in the literature as a non-selective agonist that engages several of these subtypes, including MC1R, MC3R, MC4R, and MC5R. MC1R is the subtype most directly linked to melanin production in skin cells. Because the compound is not subtype-selective, its observed effects in experimental settings are generally attributed to activity across multiple receptor pathways rather than to a single target.
Melanotan-2 is a synthetic linear peptide built from seven amino acids arranged in a short chain. Its sequence is commonly written as Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH2, which includes a modified N-terminus and an amidated C-terminus. The molecule belongs to the melanocortin family and acts as a receptor agonist. Structural features such as the D-phenylalanine residue and the Nle substitution are associated with increased stability against enzymatic degradation relative to the natural parent peptide.
| 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 |
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.
Research interest has centred on photoprotection and pigmentation, with a smaller body of work on appetite and sexual function. Published human data remain limited to small, frequently uncontrolled studies, and the compound has never received marketing approval from a national medicines regulator. Most laboratory work treats it as a pharmacological tool for probing melanocortin signalling in cell culture or animal models. Whether pigmentation changes observed in people translate into measurable protection against ultraviolet-induced DNA damage remains an open question.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, the naturally occurring peptide involved in pigmentation signalling. Its sequence is conventionally written as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, with a lactam bridge joining the aspartate side chain to the lysine side chain. The empirical formula is C50H69N15O9 and the monoisotopic mass lies near 1023.5 daltons. N-terminal acetylation and the D-configured phenylalanine both increase resistance to enzymatic breakdown compared with the parent hormone.
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.
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.
No regulatory authority has approved melanotan-2 for human use, and several countries classify it as a prescription-only or controlled substance, which restricts lawful supply. Material sold online is generally labelled as a research chemical and is not required to meet pharmaceutical standards of identity or purity. Published human data consist mainly of small uncontrolled studies, case reports and adverse-event notifications, so the evidence base is descriptive rather than confirmatory. Whether repeated melanocyte stimulation alters long-term naevus behaviour remains an open question that no completed trial has resolved.
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.
Pharmacokinetics is the study of the bodily absorption, distribution, metabolism, and excretion of drugs. When describing the pharmacokinetic properties of the chemical that is the active ingredient or active pharmaceutical ingredient, pharmacologists are often interested in L-ADME:
Due to their role in bacterial communication, 2,5-DKPs have a potential to be used as a medicine to treat bacterial diseases. For example, the 2,5-DKP cis-cyclo(Leu-Tyr) has been shown to inhibit bacterial biofilm formation; this property can be utilized to treat infections caused by the bacterial biofilm formation. These chemicals can be used to imitate quorum sensing signals to regulate gene expression of pathogenic bacteria and help fight against bacterial infection.
== External links == MBInfo – Matrix metalloproteinases (MMPs) facilitate extracellular matrix disassembly[link removed] The Matrix Metalloproteinase Protein Extracellular proteolysis at fibrinolysis.org Currently identified substrates for mammalian MMPs at clip.ubc.ca Matrix+metalloproteinases at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
However, it is also in contrast to higher doses of doxepin (50 to 300 mg/day), which have been found to significantly reduce latency to sleep onset. A positive dose–response relationship on sleep measures was observed for doses of doxepin between 1 and 6 mg in clinical studies, whereas the incidence of adverse effects remained constant across this dose range in both young and older adults. However, the incidence of adverse effects appeared to increase with longer treatment duration. A dose of doxepin as low as 1 mg/day was found to significantly improve most of the assessed sleep measures, but unlike the 3 and 6 mg/day doses, was not able to improve wake time during sleep. This, along with greater effect sizes with the higher doses, was likely the basis for the approval of the 3 and 6 mg doses of doxepin for insomnia and not the 1 mg dose. At very low doses, doxepin has not shown discontinuation or withdrawal effects nor rebound insomnia. Sustained effectiveness without apparent tolerance was demonstrated in clinical studies of up to 12 weeks duration. This appears to be in contrast to over-the-counter antihistamines like diphenhydramine and doxylamine and all other first-generation antihistamines, which are associated with rapid development of tolerance and dependence (by day 3 or 4 of continuous dosing) and loss of hypnotic effectiveness. It is for this reason that, unlike doxepin, they are not recommended for the chronic management of insomnia and are advised for only short-term treatment (i.e., 1 week).
=== Soluble (sRAGE) === The soluble form of RAGE (sRAGE) only includes the extracellular domain and lacks both the transmembrane and cytoplasmic domains. sRAGE can be generated through two primary mechanisms:
Sources: en.wikipedia.org
In February 2018, Teva Pharmaceutical Industries Ltd has completed the sale of a portfolio of products within its global women's health business across contraception, fertility, menopause and osteoporosis for $703 million in cash to CVC Capital Partners Fund VI. Teva also agreed to sell its Plan B One-Step and its brands of emergency contraception to Foundation Consumer Healthcare for $675 million in cash. Combined annual net sales of these products were $140 million last year. It also sold Paragard to a unit of Cooper Companies Inc (COO.N) for $1.1 billion.
==== Food ==== In the 1980s, W. R. Grace had owned the following restaurants: American Cafe, Del Taco, Coco's Bakery, El Torito, Hungry Tiger and various restaurants it had purchased from General Mills. In 1986, the company sold its restaurants and retained a 49 percent interest in the restaurant operations. The restaurant chains included Coco's, Houlihan's Old Place, Charley Brown's and Bristol Bar and Grill. The transaction also included El Torito Restaurants Inc., of which Grace had owned 73 percent. Charles H. Erhart Jr., vice chairman of Grace, said:While it is still too early to make a definitive estimate, we expect total proceeds to Grace to exceed $500 million from this transaction. In the process of leaving the restaurant business, the company later sold Del Taco to PepsiCo's Taco Bell in 1992.
=== tim-tin === Tim-AK Timecelles timefurone (INN) timegadine (INN) timelotem (INN) Timentin timepidium bromide (INN) timiperone (INN) timirdine (INN) timobesone (INN) timofibrate (INN) Timolide timolol (INN) timonacic (INN) timoprazole (INN) Timoptic tinabinol (INN) Tinactin Antifungal Tinaderm Tinamed tinazoline (INN) TinBen Tindal Tindamax Ting tinidazole (INN) tinisulpride (INN) tinofedrine (INN) tinoridine (INN) Tinver tinzaparin sodium (INN)
== Terminology == There exists some controversy about what structures are considered "fascia" and how they should be classified. The current version of the International Federation of Associations of Anatomists divides into:
Sources: en.wikipedia.org
In atmospheric sciences, in situ measurements refer to observations of atmospheric properties obtained using instruments placed within the environment being studied. Aircraft, balloons, and rockets are used to carry some of these instruments, allowing for direct interaction with the air to collect data. For example, radiosondes, carried aloft by weather balloons, measure atmospheric parameters such as temperature, humidity, and pressure as they ascend through the atmosphere, while anemometers, typically positioned at ground level or on towers, record wind speed and direction at specific locations. In contrast, remote sensing techniques, such as weather radar and satellite observations, collect atmospheric data from a distance by using electromagnetic radiation to infer properties without direct contact with the atmosphere.
The Neolithic Revolution (or First Agricultural Revolution) brought about an acceleration of technological innovation, and a consequent increase in social complexity. The invention of the polished stone axe was a major advance that allowed large-scale forest clearance and farming. This use of polished stone axes increased greatly in the Neolithic but was originally used in the preceding Mesolithic in some areas such as Ireland. Agriculture fed larger populations, and the transition to sedentism allowed for the simultaneous raising of more children, as infants no longer needed to be carried around by nomads. Additionally, children could contribute labor to the raising of crops more readily than they could participate in hunter-gatherer activities. With this increase in population and availability of labor came an increase in labor specialization. What triggered the progression from early Neolithic villages to the first cities, such as Uruk, and the first civilizations, such as Sumer, is not specifically known; however, the emergence of increasingly hierarchical social structures and specialized labor, of trade and war among adjacent cultures, and the need for collective action to overcome environmental challenges such as irrigation, are all thought to have played a role. The invention of writing led to the spread of cultural knowledge and became the basis for history, libraries, schools, and scientific research.
== Sources == Abu Izzedin, Nejla M. (1993) [1984]. The Druzes: A New Study of Their History, Faith, and Society (2nd ed.). Leiden and New York: Brill. ISBN 90-04-09705-8. Aytekin, E. Attila (2012). "Peasant Protest in the Late Ottoman Empire: Moral Economy, Revolt, and the Tanzimat Reforms". International Review of Social History. 57 (2): 191–227. doi:10.1017/S0020859012000193. hdl:11511/48429. Aalund, Flemming (1992). Vernacular Tradition and the Islamic Architecture of Bosra (PDF) (PhD). Copenhagen: The Royal Academy of Fine Arts School of Architecture. Batatu, H. (1999). Syria's Peasantry, the Descendants of Its Lesser Rural Notables, and Their Politics. Princeton University Press. ISBN 0-691-00254-1. Betts, Robert Brenton (1988). The Druze. New Haven: Yale University Press. ISBN 0-300-04100-4. Burkitt, Francis C. (1925). The Religion of the Manichees: Donnellan Lectures 1924. Cambridge, England: Cambridge University Press. OCLC 79046876. Chehab, Hafez (1994). "Reconstructing the Medici Portrait of Fakhr al-Din Maʾani". Muqarnas. 11: 117–124. doi:10.2307/1523213. JSTOR 1523213. Cross, Frank L.; Livingstone, E.A., eds. (2005). Oxford Dictionary of the Christian Church. Oxford University Press. ISBN 978-0-19-280290-3. Archived from the original on May 15, 2019. Retrieved October 8, 2020. Daftary, Farhad (2007). The Ismāʿı̄lı̄s: Their History and Doctrines (Second ed.). Cambridge: Cambridge University Press. ISBN 978-0-521-61636-2. Dana, Nissi (2003). The Druze in the Middle East: Their Faith, Leadership, Identity and Status. University of Michigan Press. p. 56.
Depressants are psychoactive drugs that temporarily diminish the function or activity of a specific part of the body or mind. Colloquially, depressants are known as "downers", and users generally take them to feel more relaxed and less tense. Examples of these kinds of effects may include anxiolysis, sedation, and hypotension. Depressants are widely used throughout the world as prescription medicines and as illicit substances. When these are used, effects may include anxiolysis (reduction of anxiety), analgesia (pain relief), sedation, somnolence, cognitive/memory impairment, dissociation, muscle relaxation, lowered blood pressure/heart rate, respiratory depression, anesthesia, and anticonvulsant effects. Depressants exert their effects through a number of different pharmacological mechanisms, the most prominent of which include potentiation of GABA or opioid activity, and inhibition of adrenergic, histamine or acetylcholine activity. Some are also capable of inducing feelings of euphoria. The most widely used depressant by far is alcohol (i.e. ethanol). Stimulants or "uppers", such as amphetamines or cocaine, which increase mental or physical function, have an opposite effect to depressants. Depressants, in particular alcohol, can precipitate psychosis. A 2019 systematic review and meta-analysis by Murrie et al. found that the rate of transition from opioid, alcohol and sedative induced psychosis to schizophrenia was 12%, 10% and 9% respectively.
== Safety == The acute toxicity of TMU is moderate. However, it is embryotoxic and teratogenic towards several animal species. TMU has been demonstrated to exhibit dermal and eye irritation. The sensitization potential of TMU was shown to be low compared (non-sensitizing at 1% in LLNA testing according to OECD 429).
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.
No. Melanotan-2 is manufactured synthetically. The naturally occurring peptide in the same family is alpha-melanocyte-stimulating hormone, which the body produces as part of normal endocrine and neural signalling.