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 2026-07-05 and is reviewed periodically as new material appears.
Melanotan-2 is a synthetic linear peptide built from seven amino acids arranged in a short chain. Its sequence is commonly written as Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH2, which includes a modified N-terminus and an amidated C-terminus. The molecule belongs to the melanocortin family and acts as a receptor agonist. Structural features such as the D-phenylalanine residue and the Nle substitution are associated with increased stability against enzymatic degradation relative to the natural parent peptide.
The compound emerged from research programs in the 1980s that examined analogues of alpha-melanocyte-stimulating hormone for pigmentation and photoprotection. Investigators modified the native sequence to extend activity duration and potency. A related analogue, afamelanotide, was developed within the same broad line of inquiry and eventually gained approval in certain jurisdictions for a rare light-sensitivity condition. Melanotan-2 itself did not progress through the same regulatory route and has no approved therapeutic indication.
Receptor binding at MC1R on melanocytes raises intracellular cyclic AMP and increases expression of tyrosinase and related enzymes. The downstream result is greater synthesis of eumelanin, the dark pigment, without ultraviolet exposure acting as the trigger. The compound is not selective, however, and also engages MC3R, MC4R and MC5R, which are expressed in the central nervous system and elsewhere. That lack of selectivity is the explanation usually offered for effects reported outside pigmentation, including appetite suppression and nausea. Selectivity remains a central theme in comparative studies of related peptides.
Human data remain limited and mostly short-term. Reports describe small trials and observational accounts rather than large controlled studies, so questions about dose-response relationships and long-term effects on melanocytes stay open. Whether repeated exposure alters naevus behaviour is not settled in the published record. Researchers also note that self-administered use outside clinical settings makes actual exposure difficult to quantify. Statements about efficacy and safety should therefore be read as preliminary rather than established.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Free base; salt forms differ |
| Molecular weight | Approximately 1024 g/mol | Calculated for the free base |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water and polar solvents | Poorly soluble in non-polar solvents |
| Typical storage | -20 degrees Celsius, dry, protected from light | Refers to the solid form |
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.
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.
The peptide acts as a non-selective agonist at melanocortin receptors, showing affinity for MC1R, MC3R, MC4R and MC5R. Activation of MC1R on melanocytes drives the conversion of tyrosine into melanin and shifts production toward the darker eumelanin form. MC4R signalling in the central nervous system is linked to appetite and energy balance, which helps explain why reduced food intake appeared in early human studies. Effects on MC4R and on vascular tone also account for the erectile responses recorded as unexpected findings in those same trials.
Melanotan-2 is frequently confused with afamelanotide, a linear analogue authorised in the European Union for erythropoietic protoporphyria. The two compounds differ in chain length, ring structure and receptor selectivity, so findings for one cannot be transferred directly to the other. Published controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports. Questions about effect size, dose-response behaviour and long-term safety therefore remain unresolved.
), i.e. a nonlinear set of differential equations with periodically varying parameters. It is well known that this class of dynamical systems may undergo very interesting and complex phenomena of nonlinear parametric resonance. It is easy to see that if:
Defence Minister Judith Collins announces that the New Zealand Government will be investing NZ$12 billion in the New Zealand Defence Force over the next four years to raise defence spending to over 2 percent of GDP. Australian outdoor media company QMS acquires Oaktree Capital Management's 45 percent stake in Mediaworks New Zealand, gaining full control of the commercial radio company. 8 April: A tornado in Levin causes roofs to blow off houses, and trees and fences to fall over. Labour Member of Parliament David Parker announces he will retire from Parliament, effective next month. Climate Change Minister Simon Watts confirms that the New Zealand Government will shut down its green investment bank New Zealand Green Investment Finance. 9 April – The Grey District Council issues a boil water notice after coliforms were found in the water supply zones of Stillwater, Cobden, and Kaiata, and Escherichia coli was detected in Kaiata. 10 April – The New Zealand Parliament votes 112–11 to reject the Treaty Principles Bill. 11 April: Veterans Minister Chris Penk announces that the New Zealand Government will expand the legal definition of veterans and create a new national veterans day. Foreign Minister Winston Peters confirms plans to ease visa requirements for visitors from Pacific Islands Forum member states in July and November 2025. 16 April: The Otago and Southland Regions experience Internet and mobile outages after fibre optic cables are damaged by rodents and a contractor by accident. A fire near Paremata railway station in Porirua disrupts the Kāpiti Line.
=== Mathematics === RP (complexity), randomized polynomial time, a class in computational complexity theory Ranked Pairs, a Condorcet voting method Real projective line Real projective plane Real projective space
During examinations of the head and torso, this scattered radiation can spread throughout the body and is difficult to shield with radiation protective clothing. Fears that a lead apron will prevent radiation from leaving the body are unfounded, however, because lead absorbs radiation rather than scattering it. When preparing an orthopantomogram (OPG) for a dental overview radiograph, it is sometimes recommended not to wear a lead apron, as it does little to shield scattered radiation from the jaw area, but may hinder the rotation of the imaging device. However, according to the 2018 X-ray regulation, it is still mandatory to wear a lead apron when taking an OPG.
Sources: en.wikipedia.org
Cash inflows and outflows are the money that is put into, or received from, the property including the original purchase cost and sale revenue over the entire life of the investment. An example of this sort of investment is a real estate fund. Cash inflows include the following:
Nussio, Enzo; Ugarriza, Juan E. (2021). "Why Rebels Stop Fighting: Organizational Decline and Desertion in Colombia's Insurgency". International Security. 45 (4): 167–203. doi:10.1162/isec_a_00406. hdl:20.500.11850/480000. ISSN 0162-2889. Sherman, John W. "Political Violence in Colombia: Dirty Wars Since 1977." History Compass (Sep 2015) 13#9 pp 454–465. Cirlig, Carmen-Cristina. "Colombia: new momentum for peace?" (PDF). Library Briefing. Library of the European Parliament. Retrieved July 15, 2013. Azcarate, Camilo A. (March 1999). "Psychosocial Dynamics of the Armed Conflict in Colombia". Online Journal of Peace and Conflict Resolution. Archived from the original on January 6, 2003. James Petras (July 2, 1988). "Neglected Dimensions of Violence". Economic and Political Weekly. 23 (27): 1367. JSTOR 4378701. Elizabeth F. Schwartz (Winter 1995–1996). "Getting Away with Murder: Social Cleansing in Colombia and the Role of the United States". The University of Miami Inter-American Law Review. 27 (2): 381–420. John Lindsay-Poland (January–February 2010). "Retreat to Colombia: The Pentagon Adapts Its Latin America Strategy". NACLA Report on the Americas. Government/NGO reports
== Personal life == Moriber married fellow medical student Julian Katz in 1963. They had two children, Jonathan and Sara, both of whom became physicians. Her husband died in 2014, and she died in 2023, at her home in Gladwyne, Pennsylvania, at the age of 80, from complications related to Parkinson's disease.
Microfluidics allows for the isolation of individual cells for further analyses. The following principles outline the various microfluidic processes for single-cell separation: droplet-in-oil-based isolation, pneumatic membrane valving, and hydrodynamic cell traps. Droplet-in-oil-based microfluidics uses oil-filled channels to hold separated aqueous droplets. This allows the single cell to be contained and isolated from inside the oil-based channels. Pneumatic membrane valves manipulate air pressure to isolate individual cells by membrane deflection. The manipulation of the pressure source allows the opening or closing of channels in a microfluidic network. Typically, the system requires an operator and is limited in throughput.
Throughout Eastern Europe and the Middle East, only 80% of the population own refrigerators. In addition to this, 65% of the population in China are stated to have refrigerators. The distribution of consumer refrigerators is also skewed as urban areas exhibit larger refrigeration ownership percentages compared to rural areas.
Sources: en.wikipedia.org
== Early life and education == King was born in 1934 in an army family. Since childhood, King enjoyed hiking and camping. He graduated from Episcopal High School in Alexandria, Virginia. He received a B.E. in chemical engineering from Yale University in 1956. He then entered Massachusetts Institute of Technology, where he received S.M. in chemical engineering in 1958 and Sc.D. in chemical engineering in 1960, under the supervision of J. Edward Vivian.
== Impact on victims == Corrective rape and other accompanying acts of violence can result in physical and psychological trauma, mutilation, unwanted pregnancy, and may contribute to suicide. Corrective rape is a major contributor to HIV infection in South African lesbians. In South Africa, approximately 10% of lesbians are HIV positive, with corrective rape being the most likely cause. HIV in South Africa is an epidemic, and due to homophobia, there is a lack of education about sexually transmitted diseases among lesbians. Homophobic laws and discrimination in South Africa contribute to the poor quality of health care for minorities. The psychological effects of corrective rape on victims can be detrimental. Many victims in countries such as South Africa and India where corrective rape is most prevalent suffer from a strong sense of insecurity and disempowerment due to strong homophobia in their communities. However, violence against the LGBTQ community in South Africa is seldom reported. Many survivors of corrective rape suffer from triple discrimination for being women, Black, and homosexual. This is especially true in South African townships, where corrective rape is common for lesbian women. Corrective rape victims may suffer from depression, anxiety, and/or post-traumatic stress disorder. Due to racial and sexual discrimination in health care, victims must often deal with these issues on their own.
Moreover, the apparent effect of PPIs cannot be caused by publication bias, according to a meta-analysis on 49 studies (2009). PPIs studied included producing gratitude letters, performing optimistic thinking, replaying positive life experiences, and socializing with people. Also, in a newer meta-analysis (39 studies, 6,139 participants, 2012), the standardized mean difference was 0.34 higher for subjective well-being, 0.20 for psychological well-being and 0.23 for depression. Three to six months after the intervention, the effects for subjective well-being and psychological well-being were still significant, so effects seem fairly sustainable. However, in high-quality studies, the positive effect was weaker, though positive, so authors considered further high-quality studies necessary to strengthen the evidence. They claimed that the above-mentioned meta-analysis (2009) did not put enough weight on the quality of studies. PPIs found positive included blessings, kindness practices, taking personal goals, and showing gratitude. The interventions called "Gratitude Journaling" and "Three Good Things" seem to operate via gratitude. There is evidence that, when gratitude journaling, focussing on quality over quantity as well as people more than possessions, yields greater benefits. There is also evidence of a diminished effect from gratitude journaling if it is done more than once or twice a week.
== Natural occurrence == An impure copper salt of the acid, with the formula Cu(C3N3O3H2)2(NH3)2, is currently the only known isocyanurate mineral, called joanneumite. It was found in a guano deposit in Chile. It is very rare.
Sources: en.wikipedia.org
No. Melanotan-2 is manufactured synthetically. The naturally occurring peptide in the same family is alpha-melanocyte-stimulating hormone, which the body produces as part of normal endocrine and neural signalling.
Both are synthetic analogues derived from the same parent hormone. Reference descriptions usually characterise afamelanotide as more selective for the MC1R subtype, whereas melanotan-2 is reported to interact with a wider range of melanocortin receptors.
Early studies explored melanocortin signalling and pigmentation, which later led to informal use of the label tanning peptide. That label is not a regulatory category and does not imply approved status for any purpose.
It is a synthetic cyclic heptapeptide and a non-selective melanocortin receptor agonist. Structurally it is modelled on alpha-melanocyte-stimulating hormone, a peptide that occurs naturally in the body.