Everything below concerns alpha-MSH analogue. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-06-07. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Melanotan-2 appears on the World Anti-Doping Agency prohibited list within the peptide hormone class, and several national regulators treat it as an unapproved prescription substance. Some countries restrict importation or sale for personal use. Because the compound is widely traded as a research chemical, the practical legal picture differs between jurisdictions and shifts over time. Human safety data covering long periods are limited, and whether repeated pigmentation changes carry any lasting risk to melanocytes remains an open question.
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.
| 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 |
Pharmacologically, melanotan-2 behaves as a non-selective agonist across the melanocortin receptor family. Binding at MC1R on dermal melanocytes promotes eumelanin synthesis, which underlies the tanning response described in early human work. Activity at the centrally expressed MC4R receptor is associated with reported effects on appetite and erectile function. Because the peptide does not discriminate strongly among receptor subtypes, attributing any single observed effect to one receptor pathway is generally not possible without selective antagonists or receptor knockout models.
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.
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.
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.
The most significant evolutionary theory before Darwin's was that of Jean-Baptiste Lamarck; based on the inheritance of acquired characteristics (an inheritance mechanism that was widely accepted until the 20th century), it described a chain of development stretching from the lowliest microbe to humans. The British naturalist Charles Darwin, combining the biogeographical approach of Humboldt, the uniformitarian geology of Lyell, Thomas Malthus's writings on population growth, and his own morphological expertise, created a more successful evolutionary theory based on natural selection; similar evidence led Alfred Russel Wallace to independently reach the same conclusions. The 1859 publication of Darwin's theory in On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life is often considered the central event in the history of modern biology. Darwin's established credibility as a naturalist, the sober tone of the work, and most of all the sheer strength and volume of evidence presented, allowed Origin to succeed where previous evolutionary works such as the anonymous Vestiges of Creation had failed. Most scientists were convinced of evolution and common descent by the end of the 19th century. However, natural selection would not be accepted as the primary mechanism of evolution until well into the 20th century, as most contemporary theories of heredity seemed incompatible with the inheritance of random variation.
What distinguishes the androgen backdoor from the classical pathway is whether 5α-reduction initiates or terminates the pathway. In the backdoor pathway, 5α-reduction of progesterone (P4) or 17α-hydroxyprogesterone (17OHP) occurs at or near the beginning of the pathway respectively. Conversely, in the classical pathway, 5α-reduction is the final step, where testosterone is converted into dihydrotestosterone (DHT). The backdoor pathway splits into two subpathways at P4, proceeding through either 17OHP or 5α-DHP before merging again at 5α-Pdiol. The biosynthetic intermediate 5α-Pdiol in turn is converted into DHT in two chemical steps.
=== Blood glucose === Postprandial blood glucose levels become lower after consumption of a meal containing β-glucan as a result of increased gut viscosity, which delays gastric emptying and lengthens travel through the small intestine. In one review, the net decrease in blood glucose absorption reduced postprandial blood insulin concentrations, improving insulin sensitivity. A 2021 meta-analysis of clinical trials concluded that oat beta-glucan with molecular weights greater than 300 kg/mol reduced incremental area-under-the-curve by 23%, peak blood glucose by 28%, and insulin by 22% in a dose-responsive fashion, with similar results in participants with or without diabetes. Diabetic people who increased their daily consumption of beta-glucans by more than 3 grams per day for months also lost body weight.
== See also == Scabs (disambiguation) Channeled Scablands, an eroded landscape formed by Missoula Floods in the U.S. state of Washington Scabies, a skin disease caused by the mite Sarcoptes scabiei U.S. Wheat and Barley Scab Initiative, a joint government and academic program to develop control measures to minimize the threat of Fusarium head blight (scab) in the United States
=== December === 1 December – Everton Football Club launch an appeal against the decision to dock them ten Premier League points. 2 December – Havering London Borough Council reverses its decision to cancel the display of Hanukkah candles outside its town hall, having previously said the display would not go ahead because of "escalating tensions from the conflict in the Middle East". Police declare a major incident in Cumbria, which is affected by heavy snowfall. As much as 30 cm has fallen by the following day. 5 December – Junior doctors in England will stage further strike action after rejecting the latest pay offer, the British Medical Association confirms, with a three-day strike scheduled to begin on 20 December and a six-day strike scheduled to begin on 3 January 2024. A woman, later named as Lianne Gordon, is shot dead in an incident in east London. A teenage boy and a man are also injured in the shooting. 6 December – Mayor of the West Midlands Andy Street confirms the Home Secretary has authorised his application to have the powers of the West Midlands Police and Crime Commissioner subsumed into his mayoral role from May 2024. 7 December – An inquest into the death of Ruth Perry rules that an Ofsted report "likely contributed" to the head teacher taking her life in January 2023. Six former Metropolitan Police officers are given suspended sentences after sending racist, sexist and homophobic WhatsApp messages. 9 December – A 16-year-old boy is charged with the murder of Lianne Gordon.
Sources: en.wikipedia.org
Long before the born secret issues associated with the restricted data provisions of the US Atomic Energy Act of 1946, the US Invention Secrecy Act of 1951, and the US Patent and Trademark Law Amendments Act of 1980 and/or the increasing concerns with respect to the on-going biopiracy of natural products, and in the early 20th-century atmosphere of cultural change — not only in the proliferation of vocational universities, rather than research universities, but also in the gradual move from the disciplinary concentration on "pure science" and, perhaps, aspects of "applied science", to that of fostering "industrial science" in both primary and secondary industries — the ethical question of whether or not those universities devoted to "pure science" (viz., the discovery/creation, distillation, refinement, diffusion, and the free dissemination of knowledge for the benefit of the public) should have any interest in "applied science", and further, whether they should have any commercial interest in the products of their research and, in particular, whether they should seek patents for their discoveries. In his 1926 Presidential address to the Society of American Bacteriologists (HZ.1), Hans Zinsser spoke against "the growing tendency on the part of medical scientific workers, and bacteriologists especially, to patent discoveries of practical therapeutic and public health value" (p.157).
It is thus crucial to identify the OSA for children with school difficulties; many cases remain unnoticed. Studies have shown that learning skills and behaviors can be improved if the OSA is treated, the neurocognitive and behavioral deficits are thus at least partly reversible. This reversible dimension has been postulated to be negatively correlated to the duration of the symptoms, which would mean that the longer the OSA is left untreated, the less reversible are the consequences.
== Function == The rectus abdominis is an important postural muscle. It is responsible for flexing the lumbar spine, as when doing a crunch. The rib cage is brought up to where the pelvis is when the pelvis is fixed, or the pelvis can be brought towards the rib cage (posterior pelvic tilt) when the rib cage is fixed, such as in a leg-hip raise. The two can also be brought together simultaneously when neither is fixed in space. The rectus abdominis assists with breathing and plays an important role in respiration when forcefully exhaling, as seen after exercise as well as in conditions where exhalation is difficult such as emphysema. It also helps in keeping the internal organs intact and in creating intra-abdominal pressure, such as when exercising or lifting heavy weights, during forceful defecation or parturition (childbirth).
Microfluidic devices with 2D or 3D cell cultures can be used to analyze spheroids for different cancer systems (such as lung cancer and ovarian cancer), and are essential for multiple anti-cancer drugs and toxicity tests. This strategy can be improved by increasing the throughput and production of spheroids. For example, one droplet-based microfluidic device for 3D cell culture produces 500 spheroids per chip. These spheroids can be cultured longer in different surroundings to analyze and monitor. The other advanced technology is organs‐on‐a‐chip, and it can be used to simulate several organs to determine the drug metabolism and activity based on vessels mimicking, as well as mimic pH, oxygen... to analyze the relationship between drugs and human organ surroundings. One strategy relevant to single-cell chromatin immunoprecipitation (ChiP)‐Sequencing is droplets, which operates by combining droplet‐based single cell RNA sequencing with DNA‐barcoded antibodies, possibly to explore the tumor heterogeneity by the genotype and phenotype to select the personalized anti-cancer drugs and prevent the cancer relapse.
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.
The lyophilised solid is best kept cold, dry and dark, typically at minus twenty degrees Celsius. Moisture and repeated warming cycles are the main causes of degradation. Solutions prepared from the powder are less stable and are normally used quickly.