Melanotan II raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-06-10 and is reviewed periodically as new material appears.
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.
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.
| 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 |
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.
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.
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.
== Safety == As an oxidant, silver nitrate should be properly stored away from organic compounds. It reacts explosively with ethanol. Despite its common usage in extremely low concentrations to prevent gonorrhea and control nosebleeds, silver nitrate is still very toxic and corrosive. Brief exposure will not produce any immediate side effects other than the purple, brown or black stains on the skin, but upon constant exposure to high concentrations, side effects will be noticeable, which include burns. Long-term exposure may cause eye damage. Silver nitrate is known to be a skin and eye irritant. Silver nitrate has not been thoroughly investigated for potential carcinogenic effect.
=== Parathyroid hormone-related protein === Parathyroid hormone-related protein (PTHrP) is important for endochondral bone formation. Martin (2005) found that PTHrP stimulates bone formation by increasing osteoblast differentiation and reducing osteoblast apoptosis. This causes an increase in osteoblasts allowing for new bone cells to be formed. PTHrP also regulates osteoclast formation, further allowing for bone growth.
==== Combination drugs ==== Acecarbromal/quebracho/vitamin E (Afrodor) – various actions – erectile dysfunction Aviptadil/phentolamine (Invicorp; phentolamine/aviptadil; PSD-510; Vasopotin) – combination of aviptadil (vasoactive intestinal peptide (VIP) receptor agonist) and phentolamine (α-adrenergic receptor antagonist) – erectile dysfunction [151] Papaverine/phentolamine – combination of papaverine (phosphodiesterase PDE10A inhibitor, other actions) and phentolamine (α-adrenergic recpetor antagonist) – erectile dysfunction Tadalafil/tamsulosin (Gugutams cap.; HCP-1303) – combination of tadalafil (phosphodiesterase PDE5 inhibitor) and tamsulosin (α1-adrenergic receptor antagonist) – erectile dysfunction [152]
=== Mitral regurgitation === Surgery is recommended for chronic severe mitral regurgitation in symptomatic patients with left ventricular ejection fraction (LVEF) of greater than 30%, and asymptomatic patients with LVEF of 30-60% or left ventricular end diastolic volume (LVEDV) > 40%. Surgical repair of the leaflets is preferred to mitral valve replacement as long as the repair is feasible. Mitral regurgitation may be treated medically with vasodilators, diuretics, digoxin, antiarrhythmics, and chronic anticoagulation. Mild to moderate mitral regurgitation should be followed with echocardiography and cardiac stress test every 1–3 years. Severe mitral regurgitation should be followed with echocardiography every 3–6 months.
Lethal injection dosage: 2–5 grams Sodium thiopental (US trade name: Sodium Pentothal) is an ultra-short-acting barbiturate, often used for anesthesia induction and for medically induced coma. The typical anesthesia induction dose is 0.35 grams. Loss of consciousness is induced within 30–45 seconds at the typical dose, while a 5 gram dose (14 times the normal dose) is likely to induce unconsciousness in 10 seconds. A full medical dose of thiopental reaches the brain in about 30 seconds. This induces an unconscious state. Five to twenty minutes after injection, approximately 15% of the drug is in the brain, with the rest in other parts of the body. The half-life of this drug is about 11.5 hours, and the concentration in the brain remains at around 5–10% of the total dose during that time. When a 'mega-dose' is administered, as in state-sanctioned lethal injection, the concentration in the brain during the tail phase of the distribution remains higher than the peak concentration found in the induction dose for anesthesia, because repeated doses—or a single very high dose as in lethal injection—accumulate in high concentrations in body fat, from which the thiopental is gradually released. This is the reason why an ultra-short acting barbiturate, such as thiopental, can be used for long-term induction of medical coma. Historically, thiopental has been one of the most commonly used and studied drugs for the induction of coma. Protocols vary for how it is given, but the typical doses are anywhere from 500 mg up to 1.5 grams.
Sources: en.wikipedia.org
== Prevention == The American College of Obstetricians and Gynecologists recommends all people thinking of becoming pregnant be tested to see if they have thalassemia. Genetic counseling and genetic testing are recommended for families who carry a thalassemia trait. Understanding the genetic risk, ideally before a family is started, would hopefully allow families to understand more about the condition and make an informed decision that is best for their family. A screening policy exists in Cyprus to reduce the rate of thalassemia, which, since the program's implementation in the 1970s (also including prenatal screening and abortion), has reduced the number of children born with the disease from one of every 158 births to almost zero. Greece also has a screening program to identify people who are carriers. In Iran as a premarital screening, the man's red cell indices are checked first. If he has microcytosis (mean cell hemoglobin < 27 pg or mean red cell volume < 80 fl), the woman is tested. When both are microcytic, their hemoglobin A2 concentrations are measured. If both have a concentration above 3.5% (diagnostic of thalassemia trait) they are referred to the local designated health post for genetic counseling. Large-scale awareness campaigns are being organized in India both by government and non-government organizations to promote voluntary premarital screening, with marriage between carriers strongly discouraged.
== Challenges == The space environment is expected to be beneficial for production of a variety of products assuming the obstacles to it can be overcome. The most significant cost is overcoming the energy hurdle for boosting materials into orbit. Once this barrier is significantly reduced in cost per kilogram, the entry price for space manufacturing can make it much more attractive to entrepreneurs. After the heavy capitalization costs of assembling the mining and manufacturing facilities are paid, the production will need to be economically profitable in order to become self-sustaining and beneficial to society. The economic requirements of space manufacturing imply a need to collect the requisite raw materials at a minimum energy cost. The cost of space transport is directly related to the delta-v, or change in velocity required to move from the mining sites to the manufacturing plants. Bringing material to Earth orbit from bodies such as Near-Earth asteroids, Phobos, Deimos or the lunar surface requires far less delta-v than launching from Earth itself, despite the greater distances involved. This makes these places economically attractive as sources of raw materials.
Eddy copyrighted her book, then called The Science of Life, in July 1874. Three of her students, George Barry, Elizabeth Newhall and Daniel Spofford, paid a Boston printer, W. F. Brown and Company, $2,200 to produce the first edition. The printer began work in September 1874, but stopped whenever the advance payment ran out, so progress was slow. The book—Science and Health by Mary Baker Glover, with eight chapters and 456 pages—finally appeared on October 30, 1875, published in the name of the Christian Science Publishing Company. The book was positively received by Amos Bronson Alcott, who in 1876 wrote to Eddy that she had "reaffirm[ed] in modern phrase the Christian revelations," and that he was pleased it had been written by a woman. The printer's proofreading had been poor. Martin Gardner called the first edition a "chaotic patchwork of repetitious, poorly paragraphed topics," with spelling, punctuation and grammatical mistakes. Eddy changed printers for the second edition, which was also poorly proofread, and for the third edition in 1881 switched again, this time to John Wilson & Sons, University Press, Cambridge, MA. John Wilson and his successor, William Dana Orcutt, continued to print the book until after Eddy's death. To the 6th edition in 1883, Eddy added with a Key to the Scriptures (later retitled with Key to the Scriptures), a 20-page glossary containing her definitions of biblical terms. The book sold 15,000 copies between 1875 and 1885. In August 1885, on the advice of John Wilson, she hired one of his proofreaders, the Rev.
==== Tumoral calcinosis ==== Tumoral calcinosis is distinguished by the accumulation of calcific masses surrounding the main joints. It mainly affects teens who are otherwise in good health. Joint function may be hampered by the subcutaneous or intramuscular calcified deposits.
Sources: en.wikipedia.org
Pempel (1966), professor of political science and former director of the Institute of Asian Studies at the University of California, Berkeley Roger Sanjek (1966), professor of anthropology at Queens College, City University of New York David Weissbrodt (1966), legal scholar at the University of Minnesota Law School known for drafting the Minnesota Protocol Jay Winter (1966), World War I specialist at Yale University Paul Gewirtz (1967), constitutional law scholar Karl Klare (1967), critical legal studies theorist Norman Friedman (1967), author and naval analyst Mott T. Greene (1967), historian of science, professor at University of Puget Sound Reza Sheikholeslami (1967), Soudavar Professor of Persian Studies at Wadham College, Oxford Jeremy Siegel (1967), professor of the Wharton School of the University of Pennsylvania Terrell Carver (1968), political theorist; professor at the University of Bristol Samuel R. Gross (1968), professor at the University of Michigan Law School; editor of the National Registry of Exonerations project Charles Lindholm (1968), University Professor of Anthropology at Boston University Alfred W. McCoy (1968), historian of Southeast Asia; professor at the University of Wisconsin–Madison Lawrence Susskind (1968), urban planner and mediator; professor at the Massachusetts Institute of Technology Jerry Avorn (1969), professor at the Harvard Medical School William Boone Bonvillian (1969), scholar of innovation technology policy, former director of MIT's Washington, D.C.
=== Breast cancer === Pregnancy has a positive effect on the prognosis of breast cancer according to several studies and it apparently increases the chance of survival after diagnosis of breast cancer. Possible positive effects of pregnancy could be explained by the persistence of fetal cells in the blood and maternal tissues. Fetal cells are probably actively migrating from peripheral blood into the tumor tissue where they are preferentially settled in the tumor stroma and one their concentration decreases as they get closer to the healthy breast tissue. There are two suggested mechanisms by which the fetal cells could have the positive effect on the breast cancer prognosis. The first mechanism suggests that fetal cells only oversee cancer cells and they attract components of the immune system if needed. The second option is that the down-regulation of the immune system induced by the presence of fetal cells could ultimately lead to cancer prevention, because women in whom FMC is present produce lower concentrations of inflammatory mediators, which may lead to the development of neoplastic tissue. The effect also depends on the level of microchimerism: Hyperchimerism (a high rate of microchimerism) and hypochimerism (a low rate of microchimerism) can be related to the negative effect of FMC and thus can promote a worse prognosis of breast cancer. Apparently, women with breast cancer may fail in the process of obtaining and maintaining allogeneic fetal cells.
Compared to amorphous structures, semi-crystalline structures lead to a higher stiffness, density, melting temperature and higher resistance of a polymer. Cross-linked polymers: Wide-meshed cross-linked polymers are elastomers and cannot be molten (unlike thermoplastics); heating cross-linked polymers only leads to decomposition. Thermoplastic elastomers, on the other hand, are reversibly "physically crosslinked" and can be molten. Block copolymers in which a hard segment of the polymer has a tendency to crystallize and a soft segment has an amorphous structure are one type of thermoplastic elastomers: the hard segments ensure wide-meshed, physical crosslinking.
== Mechanics of Micronization == The size reduction achieved by mechanical micronization depends on both the mill and the material being ground. The breakage behaviour of a material can be characterised by material parameters derived from single-particle impact tests, which quantify a particle's resistance to fracture and the minimum specific energy it can absorb without breaking; these allow the breakage probability of different materials to be described by a common master curve.
He sponsored Proposition B to require Muni and other city departments to develop detailed customer service plans. The measure passed with 56.6% of the vote. Newsom sponsored a ballot measure from Rescue Muni; a version of the measure was approved by voters in November 1999. Newsom also supported allowing restaurants to serve alcohol at their outdoor tables, banning tobacco advertisements visible from the streets, stiffer penalties for landlords who run afoul of rent-control laws, and a resolution, which was defeated, to commend Colin Powell for raising money for youth programs. Newsom's support for business interests at times strained his relationship with labor leaders. During Newsom's time as supervisor, he supported housing projects through public-private partnerships to increase homeownership and affordable housing in San Francisco. He supported HOPE, a failed local-ballot measure that would have allowed an increased condo-conversion rate if a certain percentage of tenants within a building were buying their units. As a candidate for mayor, he supported building 10,000 new housing units to create 15,000 new construction jobs. Newsom's signature achievement as a supervisor was a voter initiative called Care Not Cash (Measure N), which offered care, supportive housing, drug treatment, and help from behavioral health specialists for the homeless in lieu of direct cash aid from the state's general assistance program. Many homeless rights advocates protested against the initiative.
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 an analogue of alpha-melanocyte-stimulating hormone. The molecule is produced by chemical synthesis rather than extracted from a biological source.