Everything below concerns melanogenesis. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-07-09. 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.
Human data remain limited and mostly short-term. Reports describe small trials and observational accounts rather than large controlled studies, so questions about dose-response relationships and long-term effects on melanocytes stay open. Whether repeated exposure alters naevus behaviour is not settled in the published record. Researchers also note that self-administered use outside clinical settings makes actual exposure difficult to quantify. Statements about efficacy and safety should therefore be read as preliminary rather than established.
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.
| 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 emerged from research programs in the 1980s that examined analogues of alpha-melanocyte-stimulating hormone for pigmentation and photoprotection. Investigators modified the native sequence to extend activity duration and potency. A related analogue, afamelanotide, was developed within the same broad line of inquiry and eventually gained approval in certain jurisdictions for a rare light-sensitivity condition. Melanotan-2 itself did not progress through the same regulatory route and has no approved therapeutic indication.
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.
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.
== Further reading == Rhodesians Never Die, Godwin, P. & Hancock, I., 1995. Baobab Books, Harare, Zimbabwe. Pollard, William C. A Career of Defiance: The Life of Ian Smith, Agusan River Publishing Co., 1992. Topeka, KS. McLaughlin, John . "Ian Smith and the Future of Zimbabwe," The National Review, October 30, 1981, pp. 2168–70. Facts on File, 1984 ed., p. 574.
== Function == Dietary copper enters the bloodstream primarily in its oxidized Cu(II) form. Once absorbed, Cu(II) is taken up by the hCTR1, which mediates its cellular import. At the extracellular face, the flexible N-termini extends outward and captures Cu(II) from the blood carrier protein, after that it reduces Cu(II) to Cu(I) state and preserves the reduced Cu(I) oxidation state. The extracellular domain of hCTR1 holds both Cu(II) and Cu(I) binding sites: 1MDHxHH and 22HHH, serve as two Cu(II) binding sites; 7MxMxxM and 41MMMxM, comprise the first Cu(I) binding sites in the extracellular domain of hCTR1. The extracellular hCTR1 domain is also characterized by two glycosylation sites, N15 and T27. The transmembrane domain of hCTR1 is characterized by 150MxxxM and 167GxxxG motifs. In the second transmembrane helix, M150 and M154 are considered as Cu(I)-binding residues. There are two methionine triads lining the pore, and these methionine rings have soft sulfur ligands and create the "selectivity filter" for Cu(I), that excludes harder ions such as Ca(II). The hCTR1 C-terminal domain controls the distribution of Cu(I), it plays a role in copper trafficking and regulation. It interacts with metallochaperones and with the of the 188HCH motif transfers the Cu(I) ion to Atox1. Althogether hCTR1 operates as a dynamic, adaptable transporter, delicately balancing the flexibility and selectivity of copper ions.
Technically, MPs have no right to resign their seats (though they may refuse to seek re-election). However a legal fiction allows voluntary resignation between elections; as MPs are forbidden from holding an "office of profit under the Crown", an MP wishing to resign will apply for the Stewardship of the Chiltern Hundreds or the Stewardship of the Manor of Northstead which are nominally such paid offices and thus result in the MP vacating their seat. (Accepting a salaried ministerial office does not amount to a paid office under the Crown for these purposes.) The House of Lords is a legislative chamber that is part of the Parliament of the United Kingdom. Although they are part of the parliament, its members are referred to as peers, more formally as Lords of Parliament, not MPs. Lords Temporal sit for life, Lords Spiritual while they occupy their ecclesiastical positions. Hereditary peers may no longer pass on a seat in the House of Lords to their heir automatically. The 92 who remain have been elected from among their own number, following the House of Lords Act 1999 and are the only elected members of the Lords.
== Concept == In 1975, Pizza Hut began testing concepts with Applegate's Landing. with restaurants that featured Colonial-style exteriors and eclectic interiors that included a truck with a salad bar in the bed. The chain offered much of the same pizza and pasta dishes, with some additions like hamburgers and bread pudding. Applegate's Landing went defunct in the mid-1980s except for one location in McPherson, Kansas, that closed in late 1995.
The hypothalamus is commonly known as an integration center of the brain because of its role in integrating inputs from all areas of the brain and producing a specific response. In the neuroendocrine system, the hypothalamus receives electrical signals from different parts of the brain and translates those electrical signals into chemical signals in the form of hormones or releasing factors. These chemicals are then transported to the pituitary gland and from there to the systemic circulation.
Sources: en.wikipedia.org
=== Dehydration of amides and others === Nitriles can be prepared by the dehydration of primary amides. Common reagents for this include phosphorus pentoxide (P2O5) and thionyl chloride (SOCl2). In a related dehydration, secondary amides give nitriles by the von Braun amide degradation. In this case, one C-N bond is cleaved.
== Overview == The Japan Furikake Association defines furikake as "seasoned and dried one or more kinds of marine products, agricultural products, livestock products, etc., and mixed with seaweed, sesame seeds, seasonings, and others. Its main use is to be sprinkled (in Japanese: furikake) on rice and other foods." According to this definition, gomashio (sesame salt), which is traditionally sprinkled on red bean rice, and shiso, after being used to season umeboshi (pickled plums) and dried and powdered, are also furikake. Chazuke-no-moto, a mixture that becomes chazuke when hot green tea is poured on it after sprinkling on rice, is also similar to furikake.
=== Beneficial effects === UV (specifically, UVB) causes the body to produce vitamin D, which is essential for life. Humans need some UV radiation to maintain adequate vitamin D levels. According to the World Health Organization:
==== Herbal ==== The American College of Rheumatology states that no herbal medicines have health claims supported by high-quality evidence and thus they do not recommend their use. There is no scientific basis to suggest that herbal supplements advertised as "natural" are safer for use than conventional medications as both are chemicals. Herbal medications, although labelled "natural", may be toxic or fatal if consumed. Due to the false belief that herbal supplements are always safe, there is sometimes a hesitancy to report their use which may increase the risk of adverse reactions.
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.
It is a synthetic cyclic heptapeptide and a non-selective melanocortin receptor agonist. Structurally it is modelled on alpha-melanocyte-stimulating hormone, a peptide that occurs naturally in the body.