melanotan-2 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 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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.
| 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.
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.
This core group of genes is associated with gene ontology categories such as antimicrobial response, stress response, secretion, neuron-like, reproduction, and metabolism among others. Drosophila also possesses several immune mechanisms to both shape the microbiota and prevent excessive immune responses upon detection of microbial stimuli. For instance, secreted PGRPs with amidase activity scavenge and degrade immunostimulatory DAP-type PGN in order to block Imd activation. Unlike mammals, Drosophila have innate immunity but lack an adaptive immune response. However, the core elements of this innate immune response are conserved between humans and fruit flies. As a result, the fruit fly offers a useful model of innate immunity for disentangling genetic interactions of signalling and effector function, as flies do not have to contend with interference of adaptive immune mechanisms that could confuse results. Various genetic tools, protocols, and assays make Drosophila a classical model for studying the innate immune system, which has even included immune research on the international space station.
Levamisole is one of the most common cutting agents used to lace illicit cocaine, with studies showing that between 2009 and 2016, 50–70% of all cocaine specimens worldwide contained levamisole, reflecting similar high rates of contamination across North America and Europe. Before trafficking to the United States, the cocaine is frequently adulterated with levamisole. By October 2017, this figure had risen further, with the US Drug Enforcement Administration (DEA) reporting that 87% of seized and analyzed cocaine bricks in the United States contained levamisole, making it the most common adulterant in cocaine at that time. In the body, levamisole is converted into aminorex, a substance with amphetamine-like stimulant effects and a long duration of action. Levamisole-adulterated cocaine is associated with cocaine/levamisole-associated autoimmune syndrome (CLAAS) and cocaine- and levamisole-induced vasculitis (CLIV). Reagent testing kits can be used to detect the presence of cocaine and levamisole.
=== NMR (1H and 13C) spectroscopy of metallocenes === Nuclear magnetic resonance (NMR) is the most applied tool in the study of metal sandwich compounds and organometallic species, giving information on nuclear structures in solution, as liquids, gases, and in the solid state. 1H NMR chemical shifts for paramagnetic organotransition-metal compounds is usually observed between 25 and 40 ppm, but this range is much more narrow for diamagnetic metallocene complexes, with chemical shifts usually observed between 3 and 7 ppm.
==== Effects ==== Compound 22 increases the firing rate of dopaminergic neurons in mouse ventral tegmental area (VTA) slices ex vivo similarly to the TAAR1 antagonist EPPTB. It increased the firing rate by 88% at a concentration of 100 μM, whereas EPPTB increased the firing rate by 74% at a concentration of 10 nM. Compound 22 decreased basal locomotor activity in mice in vivo significantly by 58% at 5 mg/kg and non-significantly by 26% at 30 mg/kg. It was not found to stimulate locomotion at any dose. In subsequent experiments, compound 22 did not significantly affect locomotor activity at 5 or 25 mg/kg in either normal mice or TAAR1 knockout mice. The drug dose-dependently enhanced amphetamine-induced hyperlocomotion in mice. The increases were 28% at 5 mg/kg, 44% at 15 mg/kg, 57% at 20 mg/kg, and 77% at 30 mg/kg, but no difference at 50 mg/kg. Compound 22 likewise potentiated cocaine-induced hyperlocomotion in mice. The increases were 77% at 5 mg/kg, 84% at 15 mg/kg, and 124% at 25 mg/kg. Compound 22 augmented amphetamine- and cocaine-induced stereotypy as well. In subsequent experiments, compound 22 potentiated amphetamine-induced hyperlocomotion in normal mice by 44% at a dose of 5 mg/kg but had no significant effect at doses of 2.5 and 15 mg/kg. In TAAR1 knockout mice, compound 22 augmented amphetamine-induced hyperlocomotion by 84% at a dose of 15 mg/kg. The drug dose-dependently potentiated cocaine-induced hyperlocomotion at doses of 5, 15, and 25 mg/kg to similar extents in both normal mice and TAAR1 knockout mice.
The ceremony took place at Queen Elizabeth Hall on 11 April 2024. For the first time, BAFTA released their official longlist on 14 December 2023, with the shortlisted nominees announced on 7 March 2024.
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=== IgE-independent activation === The most versatile IgE-independent receptor is known as MrgprB2 in mice and MRGPRX2 in humans. These receptors can recognize many different, mostly positively charged compounds. MrgprB2 is expressed in connective tissue mast cells but not in mucosal mast cells of mice. Binding of ligands to MrgprB2 results in activation of G-protein-signaling pathways.
True muscle weakness (or neuromuscular weakness) describes a condition where the force exerted by the muscles is less than would be expected, for example muscular dystrophy. Perceived muscle weakness (or non-neuromuscular weakness) describes a condition where a person feels more effort than normal is required to exert a given amount of force but actual muscle strength is normal, for example myalgic encephalomyelitis/chronic fatigue syndrome. In some conditions, such as myasthenia gravis, muscle strength is normal when resting, but true weakness occurs after the muscle has been subjected to exercise. This is also true for some cases of chronic fatigue syndrome, where objective post-exertion muscle weakness with delayed recovery time has been measured and is a feature of some of the published definitions.
== References == Dean, Adam, and Jonathan Obert. "Rewarded by Friends and Punished by Enemies: The CIO and the Taft-Hartley Act." Labor 18.3 (2021): 78-113. McCann, Irving G. Why the Taft-Hartley Law? New York: Committee for Constitutional Government, 1950. Millis, Harry A. and Brown, Emily Clark. From the Wagner Act to Taft-Hartley: A Study of National Labor Policy and Labor Relations. Chicago: University of Chicago Press, 1950.
== Components == Honey bee venom is a complex mixture of proteins and smaller molecules. The main component is melittin, which amounts to 52% of venom peptides. One of the main allergens is phospholipase A2, which amounts to 12% and is an enzyme that catalyzes the hydrolysis of phospholipids, causing degradation of cell membranes, causing cell death. Adolapin contributes 2–5% of the peptides. Further protein components include apamin (2%), a neurotoxin, hyaluronidase (2%), which dilates blood vessels, increasing their permeability and facilitating the spread of the venom, mast cell degranulating peptide (2%), tertiapin, and secapin. Small molecules in bee venom include histamine (0.1–1%), dopamine and noradrenaline.
Sources: en.wikipedia.org
Acquired progressive lymphangioma (benign lymphangioendothelioma) Acral fibrokeratoma (acquired digital fibrokeratoma, acquired periungual fibrokeratoma) Acrochordon (cutaneous papilloma, cutaneous tag, fibroepithelial polyp, fibroma molluscum, fibroma pendulum, papilloma colli, skin tag, soft fibroma, Templeton skin tag) Adenoma sebaceum Adult type of generalized eruption of cutaneous mastocytosis African cutaneous Kaposi sarcoma African lymphadenopathic Kaposi sarcoma Aggressive infantile fibromatosis AIDS-associated Kaposi sarcoma Ainhum (bankokerend, dactylolysis spontanea, sukhapakla) Angiofibroma Angiokeratoma Angiokeratoma of Fordyce (angiokeratoma of the scrotum and vulva) Angiokeratoma of Mibelli (Mibelli's angiokeratoma, telangiectatic warts) Angioleiomyoma (vascular leiomyoma) Angiolipoleiomyoma Angiolipoma Angioma serpiginosum Angiosarcoma Aponeurotic fibroma (calcifying aponeurotic fibroma, juvenile aponeurotic fibroma) Atypical fibroxanthoma Benign lipoblastomatosis (embryonic lipoma) Buschke–Ollendorff syndrome (dermatofibrosis lenticularis disseminata) Capillary aneurysms Carcinoid Cellular angiofibroma Cherry angioma (De Morgan spot, senile angioma) Chondrodermatitis nodularis chronica helicis (chondrodermatitis nodularis helicis) Chondroid lipoma Chordoma Classic Kaposi sarcoma Collagenous fibroma (desmoplastic fibroblastoma) Composite hemangioendothelioma Connective tissue nevus (collagenoma, elastoma, shagreen patch) Cutaneous endometriosis Cutaneous meningioma (heterotopic meningeal tissue, rudimentary meningocele) Cutaneous myelofibrosis Cutaneous myxoma Cutis marmorata telangiectatica congenita (congenital generalized phlebectasia, Van Lohuizen syndrome) Dermal dendrocyte hamartoma Dermatofibroma (benign fibrous histiocytoma, dermal dendrocytoma, fibrous dermatofibroma, fibrous histiocytoma, fibroma simplex, histiocytoma, nodular subepidermal fibrosis, sclerosing hemangioma) Dermatofibrosarcoma protuberans Desmoid tumor Diffuse cutaneous mastocytosis Diffuse infantile fibromatosis Dupuytren's contracture (Dupuytren's diathesis, Dupuytren's disease, palmar fibromatosis) Eccrine angiomatous hamartoma Elastofibroma dorsi Endovascular papillary angioendothelioma (Dabska tumor, Dabska-type hemangioendothelioma, hobnail hemangioendothelioma, malignant endovascular papillary angioendothelioma, papillary intralymphatic angioendothelioma) Epithelioid cell histiocytoma Epithelioid hemangioendothelioma Epithelioid sarcoma Erythrodermic mastocytosis Extraskeletal chondroma (chondroma of soft parts) Familial myxovascular fibromas Fascial hernia Fibroma of tendon sheath Fibromatosis colli (sternomastoid tumor of infancy) Fibrous hamartoma of infancy Fibrous papule of the nose (benign solitary fibrous papule, fibrous papule of the face) Folded skin with scarring (Michelin tire baby syndrome) Fordyce's spot (Fordyce's disease) Ganglion cyst Ganglioneuroma Gardner fibroma Genital leiomyoma (dartoic leiomyoma) Giant cell fibroblastoma Giant cell tumor of the tendon sheath (giant cell synovioma, localized nodular tenosynovitis, pigmented villonodular synovitis) Glomeruloid hemangioma Glomus tumor (glomangioma, solid glomus tumor, solitary glomus tumor) Granular cell tumor (Abrikossoff's tumor, Abrikossov's tumor, granular cell myoblastoma, granular cell nerve sheath tumor, granular cell schwannoma) Hamartoma Hemangiopericytoma Hemangiosarcoma Hibernoma (fetal lipoma, lipoma of embryonic fat, lipoma of immature adipose tissue) Hypertrophic scar Immunosuppression-associated Kaposi sarcoma Infantile digital fibromatosis (inclusion body fibromatosis, infantile digital myofibroblastoma, Reye tumor) Infantile hemangiopericytoma (congenital hemangiopericytoma) Infantile myofibromatosis (congenital generalized fibromatosis, congenital multicentric fibromatosis) Infantile systemic hyalinosis (juvenile systemic hyalinosis) Intradermal spindle cell lipoma Intravascular papillary endothelial hyperplasia (Masson's hemangio-endotheliome vegetant intravasculaire, Masson's lesion, Masson's pseudoangiosarcoma, Masson's tumor, papillary endothelial hyperplasia) Juvenile hyaline fibromatosis (fibromatosis hyalinica multiplex juvenilis, Murray–Puretic–Drescher syndrome) Kaposiform hemangioendothelioma (infantile kaposiform hemangioendothelioma) Kasabach–Merritt syndrome (hemangioma with thrombocytopenia) Keloid (Keloidal scar) Keratinizing metaplasia Keratocyst Klippel–Trenaunay syndrome (angioosteohypertrophy syndrome, hemangiectatic hypertrophy) Knuckle pads (heloderma) Leiomyosarcoma Lipoma Liposarcoma (atypical lipoma, atypical lipomatous tumor) Lymphangiectasis (lymphangioma) Lymphangiomatosis Malignant fibrous histiocytoma Malignant peripheral nerve sheath tumor (malignant schwannoma, neurofibrosarcoma, neurosarcoma) Mast cell sarcoma Meningocele Metastatic carcinoma Microvenular hemangioma (microcapillary hemangioma) Midline nevus flammeus (angel's kiss, salmon patch) Multifocal lymphangioendotheliomatosis (congenital cutaneovisceral angiomatosis with thrombocytopenia, multifocal lymphangioendotheliomatosis with thrombocytopenia) Multinucleate cell angiohistocytoma Multiple cutaneous and uterine leiomyomatosis syndrome (leiomyomatosis cutis et uteri, multiple leiomyomatosis, Reed's syndrome) Multiple cutaneous leiomyoma (pilar leiomyoma) Neural fibrolipoma Neuroblastoma (infantile neuroblastoma, neuroepithelioma) Neuroma cutis Neurothekeoma (bizarre cutaneous neurofibroma, cutaneous lobular neuromyxoma, myxoma of the nerve sheath, myxomatous perineurioma, nerve sheath myxoma) Nevus flammeus (capillary malformation, port-wine stain) Nevus flammeus nuchae (stork bite) Nevus lipomatosus superficialis (nevus lipomatosis of Hoffman and Zurhelle) Nevus oligemicus Nodular fasciitis (nodular pseudosarcomatous fasciits, pseudosarcomatous fasciitis, subcutaneous pseudosarcomatous fibromatosis) Oral submucous fibrosis Pachydermodactyly Palisaded encapsulated neuroma Paraneoplastic syndrome Pearly penile papules (hirsuties coronae glandis, hirsutoid papillomas) Peyronie's disease (induratio penis plastica) Phakomatosis pigmentovascularis Piloleiomyoma Plantar fibromatosis (Ledderhose's disease) Pleomorphic fibroma Pleomorphic lipoma Plexiform fibrohistiocytic tumor Porokeratotic eccrine ostial and dermal duct nevus Progressive nodular histiocytoma Proliferating angioendotheliomatosis Prominent inferior labial artery Pseudo-ainhum
MDMA has limited approved medical uses in a small number of countries, but is illegal in most jurisdictions. MDMA-assisted psychotherapy may substantially improve PTSD symptoms, response, and remission rates compared to psychotherapy alone, but the evidence is low to very low certainty and safety data are limited, with some increased transient adverse events. In the United States, the Food and Drug Administration (FDA) has given MDMA breakthrough therapy status (though there are no current clinical indications in the US). Canada has allowed limited distribution of MDMA upon application to and approval by Health Canada. In Australia, it may be prescribed in the treatment of PTSD by specifically authorised psychiatrists.
== Plot == The future United States is a dystopic irradiated wasteland known as the Cursed Earth. On the east coast lies Mega-City One, a violent metropolis with 800 million residents and 17,000 serious crimes reported daily. The only force for order are the Judges, who act as judge, jury, and executioner. The Chief Judge tasks veteran officer Judge Dredd with assessing potential recruit Cassandra Anderson, who marginally failed the aptitude tests to become a Judge, believing her powerful psychic abilities can help in the Judges' failing war against crime. Dredd warns Anderson that disobedience, incorrect sentencing, or being disarmed will result in an automatic fail. In a 200-storey slum tower block called Peach Trees, drug lord Madeline "Ma-Ma" Madrigal has three rogue drug dealers skinned and infused with Slo-Mo—an addictive new drug that reduces the user's perception of time to 1% of normal—before throwing them down the atrium from the top floor. Dredd and Anderson arrive to investigate the deaths and learn of the existence of Ma-Ma's drug den. Deciding to raid the den, they arrest Ma-Ma's henchman Kay, who Anderson psychically detects was involved in the executions, and Dredd decides to take him in for questioning. In response, Ma-Ma's forces seize the tower's security control room and seal the building using its nuclear blast shields to prevent the Judges from leaving or summoning help. Ma-Ma instructs the residents to kill the Judges or hide, forcing Dredd and Anderson to confront dozens of armed thugs.
Drive to improve quality of patient care Need to contain burgeoning healthcare costs Improve accessibility and portability of patient records Better source data for epidemiological studies Before health records can be successfully communicated and stored there must be a fundamental agreement on the definition for each individual piece of information. Terminology solutions for describing such "concepts" currently include (but are not limited to) SNOMED CT, LOINC and the NPU. Key benefits conferred by the NPU terminology include:
In MCCs, there is no deconvolution required to determine which compounds are biologically active, because each synthesis in an array has only a single product, thus the identity of the compound should be unequivocally known.
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.
No regulator in a major market has approved it for human use. It appears in research settings and in products marketed outside pharmacy channels. Legal status for personal possession varies by country.