Everything below concerns cyclic peptide. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-09-08. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Regulatory treatment varies by country. In the United States the peptide is not approved as a medicine, and products offered for human use may be treated as unapproved new drugs; some states also restrict sale. Australia, the United Kingdom, and European Union member states apply comparable restrictions to unapproved peptide products. Border agencies have seized shipments labelled as research chemicals. Classification may change over time, and the legal position for personal importation is not clearly settled in most published guidance.
Lyophilised melanotan-2 is supplied as a solid, which is more stable than a solution. The material is hygroscopic, so weighing is done quickly, in low humidity, with the container kept sealed. Reconstitution usually uses water for injection or bacteriostatic water, added down the wall of the vial to limit foaming. A reconstituted solution is held at 2 to 8 °C and kept away from light. Repeated freezing and thawing of the same vial is avoided because ice crystal formation and concentration effects degrade the peptide.
Reversed-phase high-performance liquid chromatography is the routine method for purity assessment. Peptides absorb near 214 nm because of the peptide bond, and a gradient of acetonitrile in water separates the intact peptide from deletion sequences, oxidised products, and earlier-eluting fragments at neutral pH. Electrospray ionisation mass spectrometry provides an orthogonal check: the measured mass must agree with the theoretical value. Amino acid analysis and peptide mapping confirm structure but are used less often. Reference standards remain scarce because the peptide is not described in any pharmacopoeia.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Synthetic cyclic heptapeptide |
| Molecular mass | Approximately 1024 g/mol | Depends on counter-ion content |
| Appearance | White to off-white powder | Commonly supplied as a lyophilised solid |
| Solubility | Freely soluble in water | Also dissolves in common aqueous buffers |
| Typical storage | -20 degrees Celsius, desiccated | Protect from light and repeated freeze-thaw |
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.
Freeze-dried melanotan-2 is normally kept as a desiccated powder at minus twenty degrees Celsius or lower, shielded from light and moisture. Peptides of this size degrade through hydrolysis, oxidation and deamidation, and each pathway accelerates as temperature and water activity rise. Repeated freeze-thaw cycles promote aggregation and loss of material, so aliquoting a stock solution before freezing is standard laboratory practice. Once dissolved, the solution is markedly less stable than the powder. In laboratory work, solutions are generally refrigerated and used within days rather than kept for months.
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 II binds several melanocortin receptor subtypes rather than a single target. MC1R on melanocytes drives melanin synthesis, while MC3R and MC4R participate in energy balance, appetite, and sexual response pathways. This lack of selectivity explains why reported effects extend beyond skin darkening. Substitutions at positions four and seven, including norleucine and D-phenylalanine, increase potency and resistance to peptidases. Understanding which receptor mediates which effect remains an active area of investigation.
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.
Containers with hard spouts date to early in recorded time, as evidence by archeological finds (see image). The first vessels known to be used for feeding infants had an opening at one end for filling the bottle, and a second at the other to be put into the baby's mouth. Examination of the organic residues on ancient ceramic baby bottles shows that they were used as early as 1200 BCE to feed babies with animal milk. Around 250 BCE to 300 BCE the Egyptians developed the ability to blow glass and the Romans blew clear feeding bottles of glass, but these did not obtain long-term popularity. Leather and wood were also used. By the 1700s infant-feeding vessels such as the feeding-cups, bubby-pots, and sucking-pots were also being made from materials that included pewter, tin, and silver.
Human genetics have been included within the field of bioethics since the early 1970s and the growth in the use of DNA sequencing (particularly high-throughput sequencing) has introduced a number of ethical issues. One key issue is the ownership of an individual's DNA and the data produced when that DNA is sequenced. Regarding the DNA molecule itself, the leading legal case on this topic, Moore v. Regents of the University of California (1990) ruled that individuals have no property rights to discarded cells or any profits made using these cells (for instance, as a patented cell line). However, individuals have a right to informed consent regarding removal and use of cells. Regarding the data produced through DNA sequencing, Moore gives the individual no rights to the information derived from their DNA. As DNA sequencing becomes more widespread, the storage, security and sharing of genomic data has also become more important. For instance, one concern is that insurers may use an individual's genomic data to modify their quote, depending on the perceived future health of the individual based on their DNA. In May 2008, the Genetic Information Nondiscrimination Act (GINA) was signed in the United States, prohibiting discrimination on the basis of genetic information with respect to health insurance and employment.
=== Overview === The sequence motif discovery process has been well-developed since the 1990s. In particular, most of the existing motif discovery research focuses on DNA motifs. With the advances in high-throughput sequencing, such motif discovery problems are challenged by both the sequence pattern degeneracy issues and the data-intensive computational scalability issues. Process of discovery
=== After 1997: return to business === By 1997, when his career as a Cabinet minister ended, Haymarket was making an annual profit of over £10m and employing around 1,000 people. Heseltine resumed management of the company after Masters' retirement in 1999. Haymarket has seen reduced profitability in the UK since 1999, but has expanded further into foreign markets (for example India). It has also laboured under heavy borrowings of over £100 million to buy back Masters' and Tindall's large minority shareholdings, which have been reduced to some extent by the sale of properties. Heseltine has now retired from day-to-day management, handing over to his son Rupert. Heseltine's ownership of Haymarket has made him a large personal fortune. As of 2013 he was ranked 311th in The Sunday Times Rich List with an estimated wealth, including shareholdings held by members of his immediate family, of £264 million.
== Education == Tej obtained his master's degree in science from the University of Allahabad. He started his research career in 1971 as a graduate student at the Indian Institute of Science, Bangalore. He obtained his Ph.D. degree in the mid-1970s working on the crystal structure determinations and design of anti-inflammatory analgesics for new drug discovery. [1]. Before going for his bachelor's degree in Science in Allahabad University, Tej Pal Singh has studied in his neighbourhood village school i.e. Kisan Intermediate College Deorhi-Wajidpur (District-Amroha UP) and later Government Intermediate College (GIC) in Amroha (UP).
Sources: en.wikipedia.org
His Pan-Slavic views were unleashed in this book, where he stated that the land of Slovaks should be annexed by the Tsar's empire and that eventually, the population could be not only Russified, but also converted into the rite of Orthodoxy, religion originally spread by Cyril and Methodius during the times of Great Moravia, which served as an opposition to the Catholic missionaries from the Franks. After the Hungarian invasion of Pannonia, Hungarians converted into Catholicism, which effectively influenced the Slavs living in Pannonia and in the land south of the Lechs. However, the Russian Empire often claimed Pan-Slavism as a justification for its aggressive moves in the Balkan Peninsula of Europe against the Ottoman Empire, which conquered and held the land of Slavs for centuries. This eventually led to the Balkan campaign of the Russian Empire, which resulted in the entire Balkan being liberated from the Ottoman Empire, with the help and the initiative of the Russian Empire. Pan-Slavism has some supporters among Czech and Slovak politicians, especially among the nationalistic and far-right ones, such as People's Party – Our Slovakia. The creation of an independent Czechoslovakia made the old ideals of Pan-Slavism anachronistic. Relations with other Slavic states varied, sometimes being so tense it escalated into an armed conflict, such as with the Second Polish Republic where border clashes over Silesia resulted in a short hostile conflict, the Polish–Czechoslovak War. Even tensions between Czechs and Slovaks had appeared before and during World War II.
That Florey was not a pathologist was not overlooked; the Scottish pathologist Robert Muir declared: "There is no pathologist named Florey." The faculty board decided to take a chance on Florey, and he was appointed on 9 December. He took up the appointment in March 1932. The Floreys moved for the fourth time in five years, this time to a Victorian manor on 1 acre (0.40 ha) of ground about 1 mile (1.6 km) from the university, which later became student accommodation with the name "Florey Lodge". The chair came with a salary of £1,000 (equivalent to £57,000 in 2025) per annum, but there was no provision for an assistant. He took Kent with him anyway, eventually securing 50 shillings a week (equivalent to £141 in 2025) for him from the Medical Research Council (MRC). Guy's Hospital in London offered Florey a chair in pathology in February 1933. This caused alarm at the university, for it had recently lost two of its senior professors through the retirement of John Beresford Leathes and the departure of Edward Mellanby to become the secretary of the MRC. The university officials did not wish to lose Florey as well, and they raised his salary to £1,200 per annum to induce him to stay. The Sheffield Medical School was small, with only about fourteen students each year. The lack of a first-rate pathologist was remedied when Beatrice Pullinger joined the staff in January 1934, and she became Florey's ally in successfully lifting the standard of research and teaching in the department. While Florey's main interest was lysozyme, he pursued other lines of research as well.
Recombinant DNA technology arose as a result of advances in biology that began in the 1950s and '60s. During these decades, a tradition of merging the structural, biochemical, and informational approaches to the central problems of classical genetics became more apparent. Two main underlying concepts of this tradition were that genes consisted of DNA and that DNA encoded information that determined the processes of replication and protein synthesis. These concepts were embodied in the model of DNA produced through the combined efforts of James Watson, Francis Crick, Rosalind Franklin, and Maurice Wilkins. Further research on the Watson-Crick model yielded theoretical advances that were reflected in new capacities to manipulate DNA. One of these capacities was recombinant DNA technology.
In humans, the total female diploid nuclear genome per cell extends for 6.37 Gigabase pairs (Gbp), is 208.23 cm long and weighs 6.51 picograms (pg). Male values are 6.27 Gbp, 205.00 cm, 6.41 pg. Each DNA polymer can contain hundreds of millions of nucleotides, such as in chromosome 1. Chromosome 1 is the largest human chromosome with approximately 220 million base pairs, and would be 85 mm long if straightened. In eukaryotes, in addition to nuclear DNA, there is also mitochondrial DNA (mtDNA) which encodes certain proteins used by the mitochondria. The mtDNA is usually relatively small in comparison to the nuclear DNA. For example, the human mitochondrial DNA forms closed circular molecules, each of which contains 16,569 DNA base pairs, with each such molecule normally containing a full set of the mitochondrial genes. Each human mitochondrion contains, on average, approximately 5 such mtDNA molecules. Each human cell contains approximately 100 mitochondria, giving a total number of mtDNA molecules per human cell of approximately 500. However, the amount of mitochondria per cell also varies by cell type, and an egg cell can contain 100,000 mitochondria, corresponding to up to 1,500,000 copies of the mitochondrial genome (constituting up to 90% of the DNA of the cell).
Sources: en.wikipedia.org
It is a synthetic cyclic heptapeptide and an analogue of alpha-melanocyte-stimulating hormone. The molecule is produced by chemical synthesis rather than extracted from a biological source.
It is shorter than the native hormone and carries a cyclic constraint that improves stability. These changes raise receptor potency and slow breakdown relative to the naturally occurring peptide.
Published accounts date its development to the 1980s, when researchers were generating analogues of melanocyte-stimulating hormone. That work aimed to produce more stable compounds for studying pigmentation biology.
Low temperature slows hydrolysis and oxidation, the two main routes by which the peptide backbone and side chains are modified. A lyophilised powder stored at −20 °C is more stable than one kept at room temperature, and once the material is dissolved the degradation rate rises, making refrigeration more important.