This is a working overview of melanotan-2, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-10-04 and is reviewed periodically as new material appears.
Melanotan II is a synthetic peptide analog modeled on alpha-melanocyte-stimulating hormone, a naturally occurring signaling peptide involved in pigmentation. Its structure is a cyclic heptapeptide containing two non-natural substitutions, norleucine at position four and D-phenylalanine at position seven. These modifications resist enzymatic breakdown and extend the molecule's activity relative to the native hormone. The compound binds melanocortin receptors and is studied mainly as a pharmacological tool rather than a therapeutic product. It has never received approval as a medicine in any major jurisdiction.
The compound was developed in the late 1980s and 1990s by academic researchers investigating photoprotection. The rationale held that stimulating melanin production might reduce ultraviolet damage to skin and lower skin cancer risk. Early work examined receptor binding, pigment response, and short-term tolerability in small studies. That program did not produce an approved drug, and formal development stalled after early-phase trials. Whether induced pigmentation confers meaningful photoprotection remains an open question.
Outside regulated medicine, melanotan II circulates through online vendors as a research chemical, often marketed for tanning. Products sold this way vary widely in purity, concentration, and labeling accuracy, and independent testing has documented discrepancies. Published reports describe both pigment effects and adverse reactions, including nausea, flushing, and darkening of existing moles. Long-term safety data are sparse, and no large controlled trial has established a risk profile. Questions about cumulative effects on melanocytes remain unresolved in the literature.
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 | Belongs to the melanocortin agonist family |
| Key substitutions | Nle4 and D-Phe7 | Improve resistance to enzymatic degradation |
| Molecular formula | C50H69N15O9 | Approximately 1024 g/mol |
| Regulatory status | Not approved as a medicine | Distributed as a research chemical |
| Common synonyms | Melanotan II, MT-II, MT-2 | Spelling varies across sources |
Melanotan-2, also written Melanotan II, is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, and the lactam bridge between the aspartate and lysine side chains constrains the peptide into a ring. This structural change increases receptor affinity and metabolic stability relative to the native hormone. The compound was created in the 1980s as a research tool for studying pigmentation biology.
Melanocytes are the pigment-producing cells of the skin, and they carry melanocortin-1 receptors on their surface. When the receptor is activated, cyclic adenosine monophosphate rises inside the cell and raises the activity of enzymes such as tyrosinase, which increases melanin output. Melanotan-2 binds melanocortin-1 receptors in vitro and in animal models, and this binding is generally described as the basis for the tanning effect. Other receptors account for different effects: melanocortin-4 receptors contribute to appetite and erectile signalling, while melanocortin-3 and melanocortin-5 receptors contribute to energy balance and exocrine function.
=== Gender === Over the last 33 years, a significant decrease in women's happiness leads researchers to believe that men are happier than women. In contrast, a Pew Research Centre survey found that more women are satisfied with their lives than men, overall. Other research has found no gender gap in happiness. Part of these findings could be due to the way men and women differ in calculating their happiness. Women calculate the positive self-esteem, closeness in their relationships and religion. Men calculate positive self-esteem, active leisure and mental control. Therefore, neither men nor women are at greater risk of being less happy than the other. Earlier in life, women are more likely than men to fulfill their goals (material goals and family life aspirations), thereby increasing their life satisfaction and overall happiness. However, it is later in life that men fulfill their goals, are more satisfied with their family life and financial situation and, as a result, their overall happiness surpasses that of women. Possible explanations include the unequal division of labor within the household, or that women experience more variance (more extremes) in emotion but are generally happier. Effects of gender on well-being are paradoxical: men report feeling less happy than women, however, women are more susceptible to depression.
== How it works == The spark ion source consists of a vacuum chamber containing the electrodes, which is called the spark housing. The tips of the electrodes are composed of or containing the sample and are electrically connected to the power supply. Extraction electrodes create an electric field that accelerate the generated ions through the exit slit.
== Release == Valve made a 1 GB portion of Half-Life 2 available for download in an encrypted format through Steam on August 26, 2004. On the day of release, Steam customers were able to pay, unlock the files, and play it immediately, without having to wait for the game to download. In retail, distribution was handled by Vivendi Universal Games through their Sierra Entertainment subsidiary. A demo version with the file size of a single CD was made available in December 2004 at the website of graphics card manufacturer ATI Technologies, who teamed up with Valve for the game. The demo contains a portion of two chapters: Point Insertion and "We Don't Go To Ravenholm...". The soundtrack was written by Kelly Bailey. The soundtrack, containing most of the music from Half-Life 2 and many tracks from the original Half-Life, was included with the Half-Life 2 "Gold Edition" and sold separately from Valve's online store. In 2022, fans discovered that the texture used for a corpse model originated from a photograph of a corpse published in a medical textbook, leading to criticism.
Sources: en.wikipedia.org
post-mastectomy re-creation of the breast(s); trauma damage (blunt, penetrating), disease (breast cancer), and explantation deformity (empty breast-implant socket). congenital defect correction: micromastia, tuberous breast deformity, and Poland's syndrome. primary augmentation: the aesthetic enhancement (contouring) of the size, form, and feel of the breasts. The application of the adipose fat tissue as autologous filler for injection to correct bodily defects and for breast augmentation was developed by Melvin Bircoll by way of the fat-injection method. In 1987, the surgeon Eduardo Krulig injected fat-grafts with a syringe and a blunt-tip needle, and also used a disposable fat trap to facilitate the collection of body fat and to ensure the sterility of the harvested adipocyte tissue. The doctors J. Newman and J. Levin designed a lipo-injector gun with a gear-driven plunger for the even injection of autologous fat-tissue to the breast-implant pocket. The design of the lipo-injector gun featured a ratchet-gear for accurately emplacing the fat-grafts to the breast-implant pocket; the trigger action injected 0.1 cm3 of filler. Non-surgical, fat-graft augmentations of the breast employs adipocyte fat from elsewhere in the body of the woman (up to 300 ml of body fat) with three injections of equal volume, is injected to the subpectoral space and to the intrapectoral space of the pectoralis major muscle, and to the submammary space in order to achieve a breast of natural appearance and contour.
=== Gene therapy === Gene therapy was first trialled in 2014 on a single patient, and followed by clinical trials in which several patients were successfully treated. In 2023, both exagamglogene autotemcel (Casgevy) and lovotibeglogene autotemcel (Lyfgenia) were approved for the treatment of sickle cell disease. Kendric Cromer in October 2024 became the first commercial case in the US to receive gene therapy and was discharged from Children's National Hospital. The one-off gene-editing therapy, Casgevy, also known as Exa-cel, is to be offered to patients on the National Health Service (NHS) in England as from 2025. Both Casgevy and Lyfgenia work by first harvesting the patient's HSCs, then using CRISPR gene editing to modify their DNA in the laboratory. In parallel, the person with sickle cell disease's bone marrow undergoes a myeloablation procedure to destroy the remaining HSCs. The treated cells are then infused back into the patient, where they colonise the bone marrow and eventually resume production of blood cells. Casgevy works by editing the BCL11A gene, which normally inhibits haemoglobin F (foetal haemoglobin) production in adults. The edit increases HbF production, which is not prone to sickling. Lyfgenia introduces a new gene for T87Q-globin, which coexists with the sickling beta-globin but reduces the incidence of sickling. A study published in the New England Journal of Medicine in April 2026 showed a new CRISPR gene therapy labeled renizgamglogene autogedtemcel (abbreviated to reni-cel) that increased total hemoglobin from 9.8 to 13.8g/dL.
Rosett (1953), dean of the University of Chicago Booth School of Business, Arts and Sciences at Washington University in St. Louis, and chairman of National Bureau of Economic Research Robert L. Friedheim (1955), former director of the USC School of International Relations Calvin B. T. Lee (1955), former chancellor of University of Maryland, Baltimore County and acting president of Boston University Robert E. Paaswell (1956), civil engineer, former interim president of City College of New York and CEO of Chicago Transit Authority Kenneth Gros Louis (1959), chancellor of Indiana University system Richard A. Merrill (1959), 7th dean of the University of Virginia School of Law Stephen Joel Trachtenberg (1959), president of the University of Hartford and of George Washington University David C. Levy (1960), dean of the Parsons School of Design and president of the Corcoran Gallery of Art Steven M. Cahn (1966), provost and acting president of Graduate Center of the City University of New York Dimitri B. Papadimitriou (1970), executive vice president and provost of Bard College David Rubin (1970), professor of communications and dean of S. I. Newhouse School of Public Communications Alan Cooper (1971), provost of Jewish Theological Seminary of America, former member of Sha Na Na William Germano (1972), dean of the faculty of humanities and social sciences at Cooper Union, former editor-in-chief of Columbia University Press Saul Levmore (1973), commercial law scholar, former dean of the University of Chicago Law School Ronald Mason Jr.
Sources: en.wikipedia.org
It is a synthetic cyclic peptide designed as an analog of alpha-melanocyte-stimulating hormone. It acts on melanocortin receptors and is best known from research into pigmentation. It is not an approved pharmaceutical product.
No regulatory agency has approved it for any indication. It is encountered as a research chemical sold outside pharmaceutical supply chains. Products marketed this way are not subject to the manufacturing and labeling requirements that apply to approved drugs.
Reports describe increased skin pigmentation as well as side effects such as nausea, flushing, and changes to existing moles. Much of the evidence comes from small studies and case reports rather than large trials. The long-term safety profile is therefore uncertain.
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.