Melanotan II is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-05-19. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Compound class | Synthetic cyclic heptapeptide | Alpha-MSH analogue containing a D-phenylalanine residue |
| Molecular formula | C50H69N15O9 | Average molecular mass approximately 1024.2 g/mol |
| Appearance | White to off-white lyophilised powder | Normally supplied as a freeze-dried solid in a sealed vial |
| Solubility | Freely soluble in water and polar solvents | Dissolves readily in aqueous buffers and in alcohol-water mixtures |
| Receptor targets | MC1R, MC3R, MC4R, MC5R | Acts as a non-selective melanocortin receptor agonist |
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 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.
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.
Melanocortin receptors comprise five subtypes with distinct tissue distributions and functions. Melanotan-2 is described in the literature as a non-selective agonist that engages several of these subtypes, including MC1R, MC3R, MC4R, and MC5R. MC1R is the subtype most directly linked to melanin production in skin cells. Because the compound is not subtype-selective, its observed effects in experimental settings are generally attributed to activity across multiple receptor pathways rather than to a single target.
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.
Melanotan-2 is a synthetic cyclic heptapeptide designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous tridecapeptide that regulates pigment production. Two modifications distinguish it from the natural hormone: norleucine replaces methionine at the N-terminus, which limits oxidation, and a D-phenylalanine substitution raises receptor affinity. The ring is closed through an aspartate-lysine lactam bridge, giving the molecule a constrained conformation. The free base has a molecular mass near 1024 daltons, and commercial material is usually supplied as an acetate salt. It appears in the literature as a research peptide rather than an approved therapeutic agent.
Receptor studies place melanotan-2 among non-selective melanocortin agonists, binding MC1R, MC3R, MC4R and MC5R rather than a single subtype. Activation of MC1R on cutaneous melanocytes raises tyrosinase activity and shifts pigment synthesis toward eumelanin, which is darker and more photostable than pheomelanin. Central receptors, particularly MC4R, are associated with appetite suppression and with reported effects on sexual function. Because subtype selectivity is low, the same molecule engages pigment, metabolic and vascular pathways at once, and this breadth is a common explanation offered for the range of adverse events described in user reports.
No regulatory authority has approved melanotan-2 for human use, and several countries classify it as a prescription-only or controlled substance, which restricts lawful supply. Material sold online is generally labelled as a research chemical and is not required to meet pharmaceutical standards of identity or purity. Published human data consist mainly of small uncontrolled studies, case reports and adverse-event notifications, so the evidence base is descriptive rather than confirmatory. Whether repeated melanocyte stimulation alters long-term naevus behaviour remains an open question that no completed trial has resolved.
Initially, PKCε was thought to protect mitochondria from MPT through its association with VDAC1, ANT, and hexokinase II; however, genetic studies have since ruled this out and subsequent studies have identified the F0/F1 ATP synthase as a core inner mitochondrial membrane component and Bax and Bak as potential outer membrane components These findings have opened up new avenues of investigation for the role of PKCε at mitochondria. Several likely targets of PKCε action affecting MPT have been discovered. PKCε interacts with ERK, JNKs and p38, and PKCε directly or indirectly phosphorylates ERK and subsequently Bad. PKCε also interacts with Bax in cancer cells, and PKCε modulates its dimerization and function. Activation of PKCε with the specific activator, εRACK, prior to ischemic injury has shown to be associated with phosphorylation of the F0/F1 ATP synthase. Moreover, the modulatory component, ANT is regulated by PKCε. These data suggest that PKCε may act at multiple modulatory targets of MPT function; further studies are required to unveil the specific mechanism.
=== Self-efficacy === Self-efficacy refers to a belief that one's ability to accomplish a task is a function of personal effort. Low self-efficacy, or a disconnect between ability and personal effort, is associated with depression; by comparison, high self-efficacy is associated with positive change, including overcoming abuse, overcoming eating disorders, and maintaining a healthy lifestyle. High self-efficacy also has positive benefits for one's immune system, aids in stress management, and decreases pain. A related concept, Personal effectiveness, is primarily concerned with planning and the implementation of methods of accomplishment.
Whereas, wild type fungi are known to upregulate production of azole resistance drugs such as multidrug resistance protein 1 (MDR1) and transporters Cdr1 and Cdr2 that act like pumps to remove the antifungal drugs. Sphingolipid and sterols are the majority of the lipid bilayer membrane in fungi, e.g Candida species, and assist in formation of biofilms. Understanding the mechanism is utilized for development of vaccine adjuvants. Biofilm production is initiated through quorum sensing. Example of quorum sensing are the LuxR and LuxI proteins that attribute to the bioluminescence in Vibrio fischeri, LuxI produces acyl homoserine lactones (AHL) that are received by LuxR of neighboring bacteria, a specific concentration of AHL triggers gene expression of bioluminescence. Some vaccine adjuvants focus on biofilm formation by aiming to disrupt the communication utilizing current knowledge on quorum sensing.
=== Sequencing by synthesis === The objective for sequential sequencing by synthesis (SBS) is to determine the sequencing of a DNA sample by detecting the incorporation of a nucleotide by a DNA polymerase. An engineered polymerase is used to synthesize a copy of a single strand of DNA and the incorporation of each nucleotide is monitored. The principle of real-time sequencing by synthesis was first described in 1993 with improvements published some years later. The key parts are highly similar for all embodiments of SBS and includes (1) amplification of DNA (to enhance the subsequent signal) and attach the DNA to be sequenced to a solid support (an exception is the PacBio SMRT), (2) generation of single stranded DNA on the solid support, (3) incorporation of nucleotides using an engineered polymerase and (4) real-time detection of the incorporation of nucleotide The steps 3-4 are repeated and the sequence is assembled from the signals obtained in step 4. This principle of real-time sequencing-by-synthesis has been used for almost all massive parallel sequencing instruments, including 454, PacBio, IonTorrent, Illumina and MGI.
Sources: en.wikipedia.org
Serotonin 5-HT2A receptor antagonists can block the subjective psychedelic effects of serotonergic psychedelics in humans. Numerous drugs act as serotonin 5-HT2A receptor antagonists, for instance antidepressants like trazodone and mirtazapine, antipsychotics like quetiapine, olanzapine, and risperidone, and other agents like ketanserin, pimavanserin, cyproheptadine, and pizotifen. Such drugs are sometimes referred to as "trip killers" due to their ability to prevent or abort the hallucinogenic effects of psychedelics. Serotonin 5-HT2A receptor antagonists like antipsychotics should be stopped 5 half-lives or at least 7 days prior to a psychedelic session. Besides serotonin 5-HT2A receptor antagonists, non-hallucinogenic serotonin 5-HT2A receptor partial agonists, such as lisuride, may also block the hallucinogenic effects of serotonergic psychedelics. Dopamine D2 receptor antagonists such as the typical antipsychotic haloperidol can cause anxiety and dysphoria when combined with psychedelic drugs. The same may be true of other dopamine D2 receptor antagonists such as metoclopramide. Unlike atypical antipsychotics, which also have concomitant serotonin 5-HT2A receptor antagonism, more selective dopamine D2 receptor antagonists like haloperidol do not block the hallucinogenic effects of psychedelics and hence are not useful as "trip killers". Due to the increased risk of negative experiences, it is recommended that dopamine D2 receptor antagonists like haloperidol and metoclopramide not be combined with psychedelics.
Christopher Marley (born 1969) is an artist, photographer, naturalist, and author who uses natural artifacts as his artistic medium. He is best known initially for his book Biophilia, and then for the traveling exhibit Exquisite Creatures that features his art.
=== Pharmacokinetics === After oral administration itopride undergoes rapid and extensive absorption with levels of itopride peaking in the blood plasma after only 35 minutes. Itopride is primarily eliminated via the kidneys having an elimination half-life of approximately 6 hours.
The Blood resource focus on the individual protein levels in blood of both healthy individuals and patients diagnosed with various diseases. Here you can explore: - The individual protein levels in blood from healthy individuals and patients diagnosed with diseases. - The longitudinal blood protein levels in healthy individuals during two years. - The longitudinal blood protein levels in children through puberty. - The effect of age, BMI and sex on the individual protein levels in blood. - The levels of plasma proteins using immune assays and mass spectrometry. The Subcellular resource of the Human Protein Atlas provides high-resolution insights into the expression and spatiotemporal distribution of proteins encoded by 13603 genes (67% of the human protein-coding genes) as well as predictions for an additional 3459 secreted- or membrane proteins, covering a total of 17062 genes (85% of the human protein-coding genes). For each gene, the subcellular distribution of the protein has been investigated by immunofluorescence (ICC-IF) and confocal microscopy in up to three different cell lines, selected from a panel of 42 cell lines used in the subcellular resource. Upon image analysis, the subcellular localization of the protein has been classified into one or more of 35 different organelles and fine subcellular structures. For some genes, the protein has also been stained in up to three ciliated cell lines, induced pluripotent stem cells (iPSCs) and/or in human sperm cells.
=== 1974–1977: Arrival of Neil Peart and foray into progressive rock === After auditioning five drummers, Lifeson and Lee picked Neil Peart, who joined on July 29, 1974, which was two weeks before the group's first US tour. They performed their first concert together on August 14 at the Civic Arena in Pittsburgh, opening for Uriah Heep and Manfred Mann's Earth Band to more than 11,000 people. Peart assumed the role of lyricist; Lifeson and Lee had little interest in the job and recognized Peart's wider vocabulary range from reading regularly. Lifeson and Lee focused primarily on the music, with the new material displaying their influences from progressive rock bands Yes and Pink Floyd. When the U.S. tour concluded in December 1974, Rush had reached its peak of No. 105 on the U.S. Billboard 200 chart. Fly by Night (1975), Rush's first album with Peart, saw the inclusion of the story song "By-Tor & the Snow Dog", replete with complex arrangements and a multi-section format. Lyrical themes also underwent dramatic changes because of Peart's love for fantasy and science-fiction literature. Despite the new styles, some other songs on the album mirrored the simplistic blues style found on Rush's debut. "Fly by Night" was released as a single that reached No. 45 in Canada. The album reached No. 9 in Canada, where it was certified platinum by the Canadian Recording Industry Association (CAN) for selling 100,000 copies and by the Recording Industry Association of America (RIAA) for selling 1 million copies in the U.S. Caress of Steel (1975) followed Fly by Night.
Sources: en.wikipedia.org
In May 1991, the PDRE (1987-1991) was overthrown by forces consisting of the TPLF and the TPLF-controlled EPRDF with the promise that a recognition of human rights, democracy, the liberalization of the economic sector, and political rehabilitation were soon to follow. The PDRE, the country's newest civilian regime, was actually dominated by leaders of the preceding Derg (1974-1987) a military junta led by Mengistu Haile Mariam that seized power by overthrowing the long-ruling Emperor Haile Selassie I in 1974. The Derg (meaning "committee" or "council") and its leaders were known for dramatically restructuring the country's political and economic institutions, often through the use of suppression and fear, while transforming the central government's role in domestic affairs. Programs such as the extensive villagization schemes carried out in various parts of the country further served as a testament to the regime's commitment to radical reform measures. Once in power, the leaders of the PDRE continued pursuing their aims as former Derg leaders, such as by resuming forced resettlement programs that were deemed nonviable by many and were ultimately met with a considerable amount of international criticism. Scholars have noted that the fall of the PDRE was largely made possible by the loss of both financial and military support from the dwindling Soviet Union, which had previously backed the Derg following their seizure of power in 1974.
=== Earlier leaks === In 1976, two local trade unions complained of pollution within the plant. In 1981, a worker was accidentally splashed with phosgene as he was carrying out a maintenance job of the plant's pipes. In a panic, he removed his gas mask and inhaled a large amount of toxic phosgene gas, leading to his death 72 hours later. Following these events, journalist Rajkumar Keswani began investigating and published his findings in Bhopal's local paper Rapat, in which he urged "Wake up, people of Bhopal, you are on the edge of a volcano." In January 1982, a phosgene leak exposed 24 workers, all of whom were admitted to a hospital. None of the workers had been ordered to wear protective equipment. One month later in February 1982, an MIC leak affected 18 workers. In August 1982, a chemical engineer came into contact with liquid MIC, resulting in burns over 30% of his body. In October 1982, there was another MIC leak. In attempting to stop the leak, the MIC supervisor suffered severe chemical burns and two other workers were severely exposed to the gases. During 1983 and 1984, there were leaks of MIC, chlorine, monomethylamine, phosgene, and carbon tetrachloride, sometimes in combination.
== Adverse events == In 2005, the FDA announced that they were investigating reports of death and other serious adverse events related to narcotic overdose in patients using Duragesic, the fentanyl transdermal patch for pain control. The Duragesic product label was subsequently updated to add safety information in June 2005. In 2007, Shire and Noven Pharmaceuticals, manufacturers of the Daytrana ADHD patch, announced a voluntary recall of several lots of the patch due to problems with separating the patch from its protective release liner. Since then, no further problems with either the patch or its protective packaging have been reported. In 2008, two manufacturers of the fentanyl patch, ALZA Pharmaceuticals (a division of major medical manufacturer Johnson & Johnson) and Sandoz, subsequently issued a recall of their versions of the patch due to a manufacturing defect that allowed the gel containing the medication to leak out of its pouch too quickly, which could result in overdose and death. As of March 2009, Sandoz—now manufactured by ALZA—no longer uses gel in its transdermal fentanyl patch; instead, Sandoz-branded fentanyl patches use a matrix/adhesive suspension (where the medication is blended with the adhesive instead of held in a separate pouch with a porous membrane), similar to other fentanyl patch manufacturers such as Mylan and Janssen. In 2009, the FDA announced a public health advisory warning of the risk of burns during MRI scans from transdermal drug patches with metallic backings.
In 1993, Jeffrey Ulmer and co-workers at Merck Research Laboratories demonstrated that direct injection of mice with plasmid DNA encoding a flu antigen protected the animals against subsequent experimental infection with influenza virus. In 2016 a DNA vaccine for the Zika virus began testing in humans at the National Institutes of Health. The study was planned to involve up to 120 subjects aged between 18 and 35. Separately, Inovio Pharmaceuticals and GeneOne Life Science began tests of a different DNA vaccine against Zika in Miami. The NIH vaccine is injected into the upper arm under high pressure. Manufacturing the vaccines in volume remained unsolved as of August 2016. Clinical trials for DNA vaccines to prevent HIV are underway. In August 2021, Indian authorities gave emergency approval to ZyCoV-D. Developed by Cadila Healthcare, it is the first DNA vaccine against COVID-19.
Sources: en.wikipedia.org
No. It is a laboratory-made peptide, while the natural hormone is alpha-melanocyte-stimulating hormone, a longer peptide produced by the pituitary gland and by skin cells. Melanotan-2 mimics only a short active region of that hormone and contains non-natural residues such as D-phenylalanine.
No approved regulatory indication exists in major markets. An approval exists for a different peptide, afamelanotide, which is used for a rare photosensitivity disorder called erythropoietic protoporphyria. Melanotan-2 itself remains a research compound with no cleared clinical role.
Melanocortin-1 receptors on melanocytes are the receptor most closely linked to pigment production. The peptide is not selective, however, and also activates melanocortin-3, melanocortin-4, and melanocortin-5 receptors. That lack of selectivity is the usual explanation offered for both its range of observed effects and its off-target effects.
It is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, containing seven amino acids with a lactam ring and a D-configured phenylalanine residue. It is supplied as a lyophilised powder for laboratory research.