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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 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.
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.
| 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-2 is a synthetic peptide designed as an analog of alpha-melanocyte-stimulating hormone, a signaling molecule produced in the pituitary and skin. Its structure is a linear chain of seven amino acids that folds into a ring through an internal lactam bridge joining two side chains. The compound is sometimes written as MT-II or MEL-2 in informal and commercial contexts. It belongs to the melanocortin peptide family, a group of short signaling molecules that share a conserved core sequence recognized by melanocortin receptors.
Two structural changes distinguish the synthetic peptide from the natural hormone. A norleucine residue replaces methionine at one position, and a D-configured phenylalanine replaces the natural L-form at another. Both substitutions slow enzymatic breakdown, which extends the molecule's persistence relative to the parent hormone. The lactam bridge further constrains the backbone into a stable conformation. These features are standard design strategies in peptide chemistry and are not unique to this compound; they appear across many research peptides built for improved stability.
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.
==== Turkey ==== 7-Eleven entered the Turkish market in 1989. Major stakeholder of the master franchise, Özer Çiller sold his shares in 1993, after his wife Tansu Çiller became the Prime Minister. In the 2010s, 7-Eleven left the Turkish market, transferring most of its stores to franchise owners.
In 1990, the country had a Human Development Index of 0.920, placing it in the 'high' category of human development. It was the third-highest in the Eastern Bloc, behind Czechoslovakia and East Germany, and the 25th in the world of 130 countries.
Necrophagous flies have several traits and adaptations that facilitate their feeding behavior. For example, blow flies and flesh flies have a well-developed sense of smell and are highly mobile. This enables them to rapidly detect and locate carrion. Also, flesh flies and some blow flies lay larvae instead of eggs. This gives these flies a competitive advantage over other slower-developing, egg-laying species. In addition, blow flies, flesh flies, muscid flies and black soldier flies have many defenses against the pathogens and toxins found in carrion. These include a protective lining in their midgut, antibiotic-producing microbiota species, and a large number of pattern recognition receptors, lysozymes, antimicrobial peptides and detoxification enzymes. The diversity and abundance of necrophagous fly species vary geographically and seasonally. For example, Chrysomya species are present in subtropical regions of the USA but are rare in most of Canada. This geographic variation is attributable to factors such as soil type and meteorological conditions, and the effects these have on carrion decomposition. Whether urbanization affects fly species richness is open to dispute. Seasonally, many necrophagous fly species are observed in higher abundance in summer, but Thyreophora cynophila is more active in winter. Flies play a critical role in forensic science as they are often the first insects to discover and colonize human remains. Blow flies can arrive within minutes and begin laying eggs in the nose, mouth and other openings.
Sources: en.wikipedia.org
Cristalino [kɾistaˈlino] ("crystalline"): aged tequila that has been filtered to remove its color before bottling, similar to chill filtering of whisky Rosa ("pink"): a young version of the spirit "lightly aged in red wine barrels"
A micronized tablet formulation of progesterone marketed under the brand name Luteina is indicated for use by sublingual administration in addition to the vaginal route and is approved for use in Poland and Ukraine. Sublingual progesterone may also be available from compounding pharmacies in countries like the United States. Progesterone is used by the sublingual route at dosages of 50 to 150 mg three to four times per day. A single 100 mg sublingual dose of Luteina has been found to reach mean peak progesterone levels of 13.5 ng/mL after 1 to 4 hours, with an elimination half-life of about 6 to 7 hours. A number of other studies have also investigated the use of progesterone by sublingual administration. Older studies have also explored sublingual progesterone. A study of sublingual progesterone for luteal support in patients undergoing embryo transfer found that after sublingual administration of 50 or 100 mg progesterone dissolved in a 1 mL suspension, peak levels of progesterone were reached in 30 to 60 minutes and were on average 17.61 ± 3.78 ng/mL with the 100-mg dose. However, the duration was short, with levels of less than 5 ng/mL at 6 hours, and re-administration had to be done two or three times per day for adequate circulating levels of progesterone to be maintained throughout the day. Another study found that sublingual progesterone had to be administered at a dose of 400 mg every 8 hours to achieve circulating levels similar to those produced by 100 mg/day intramuscular progesterone.
=== 6 May === The RSF launched another series of drone strikes on Port Sudan. Six people were killed by RSF shelling on the Abu Shouk camp. The Sudanese government severed diplomatic relations with the UAE due to its alleged support for the RSF.
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. 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.