If you have been reading about alpha-MSH analogue and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-01-27. Numbers and descriptions here follow the published literature rather than marketing material.
Published research on the compound remains limited. Much of the human data comes from small, early-stage studies rather than large controlled trials, and several questions about effects and variability between individuals remain open. Investigators have examined receptor activity, pigment pathways, and related physiological responses in laboratory and animal models. Findings from those models do not automatically translate to human outcomes. Reviews frequently note the scarcity of rigorous clinical evidence and call for better-characterized study material.
Because the substance circulates mainly through informal markets, verification is a recurring theme in technical discussion. Independent analyses have found that labeled content and actual content can diverge, and that purity varies between samples. Analytical laboratories use reversed-phase chromatography to separate components and mass spectrometry to confirm identity. Isotope-labeled internal standards improve quantification in complex matrices. Such methods describe what a sample contains but say nothing about its sterility, lawful status, or suitability for any use. Open questions remain about how consistently testing is applied across the supply chain.
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controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports.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.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence incorporates a lactam bridge that constrains the peptide into a ring, which increases resistance to enzymatic breakdown relative to the natural hormone. Researchers at the University of Arizona synthesised the compound in the late 1980s and early 1990s while studying pigmentation pathways. It has never received marketing approval from any national medicines regulator. In the scientific literature it is usually described as a laboratory research reagent rather than a therapeutic product.
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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved as a medicine | No marketing authorization in major jurisdictions |
| Scheduling example | Prescription-only supply in some countries | Handled as an unlicensed medicine where restricted |
| Sports classification | Prohibited peptide | Appears on anti-doping prohibited lists |
| Reported presentation | Lyophilized vial | Nominal content varies between vendors |
| Detection approach | Liquid chromatography–tandem mass spectrometry | Used in anti-doping and forensic testing |
Identification in laboratories relies on reversed-phase liquid chromatography coupled with tandem mass spectrometry, with product-ion spectra compared against a certified reference standard. High-resolution mass spectrometry supplies accurate mass confirmation, and peptide mapping after enzymatic digestion separates melanotan II from closely related analogues. Quantitation of seized material is complicated by unknown counter-ions and residual trifluoroacetate left from purification. Immunoassays raised against alpha-melanocyte-stimulating hormone can cross-react, so chromatographic confirmation is normally required. Urinary detection windows are short, and reported limits of detection differ substantially between laboratories.
Melanotan II holds no marketing authorisation from the Food and Drug Administration, the European Medicines Agency, the UK Medicines and Healthcare products Regulatory Agency or Australia's Therapeutic Goods Administration. Products sold under that name are treated as unapproved new drugs, and their sale or import is prohibited in several jurisdictions. Other countries classify the peptide as a prescription-only medicine or place it among controlled substances, so the legal position changes with the destination market. No pharmacopoeial monograph supplies an official specification, because the material is not a licensed pharmaceutical. Consequently, products offered online are not manufactured to a shared public standard.
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.
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.
=== Function === A neuropeptide is a peptide that is active in association with neural tissue. A lipopeptide is a peptide that has a lipid connected to it, and pepducins are lipopeptides that interact with GPCRs. A peptide hormone is a peptide that acts as a hormone. A proteose is a mixture of peptides produced by the hydrolysis of proteins. The term is somewhat archaic. A peptidergic agent (or drug) is a chemical which functions to directly modulate the peptide systems in the body or brain. An example is opioidergics, which are neuropeptidergics. A cell-penetrating peptide is a peptide able to penetrate the cell membrane.
=== Media === Bob Barker Studio at CBS Television City named in his honor. Time magazine's Greatest Game Show Host of All-Time GSN Lifetime Achievement Award MTV Movie Award for Best Fight in Happy Gilmore (with Adam Sandler)
== Applications == The products based on collagen proteins are used for food, health and nutrition, pharmaceutical industries and technical applications for example Photo, Ballistic, Restoration, Lubricants, Technical detergents.
=== Acquisition and expansion (2017–2025) === In late July 2017, the Chinese Room's directors, Dan Pinchbeck and Jessica Curry, laid off the entire staff—at that point eight people—and ditched their Brighton office for home. They cited the lack of ability to pay their staff during the interim between projects as the reason for the closure, and expressed their intentions that the studio itself was still running without the development team, with Pinchbeck and Curry working on prototyping and acquiring funds on their own time. The company released a VR game, So Let Us Melt, for Google Daydream in September, which was the final project of the former studio. At the time, Pinchbeck, Curry, and Andrew Crawshaw were working alone on the studio's next project, 13th Interior, which was to push away from the "walking simulator" model the studio had been known for. In August 2018, Sumo Group, the parent company of Sumo Digital, acquired the Chinese Room for £2.2 million, making it the fourth UK-based studio under Sumo Digital. Co-founder Pinchbeck took the role of creative director for the Chinese Room, while Curry continued as an independent composer for the studio. Pinchbeck described the acquisition as "the end of a chapter" for the studio as they determined their next project. From late summer 2018, the Chinese Room began re-staffing, adding veteran developers Ed Daly as studio director and John McCormack as art director. Dear Esther launched on iOS on 30 September 2019. On 12 June 2020 the Chinese Room released its first Apple Arcade game, Little Orpheus, to positive reviews.
As more African-Americans are incarcerated, the more the heuristic is enforced in the eyes of the courts, which contributes to yet higher imprisonment rates among African-American children. High numbers of African American arrests and charges of possession show that although most drug users in the United States are white, blacks are the largest group being targeted as the root of the problem. Furthermore, a study by Andrew Golub, Bruce Johnson, and Eloise Dunlap affirms the racial divide in drug arrests, notably marijuana arrests, where blacks with no prior arrests (0.9%) or one prior arrest (4.3%) were nearly twice as likely to be sentenced to jail as their white counterparts (0.4% and 2.3%, respectively). Harboring such emotions can lead to a lack of will to contact the police in case of an emergency by members of African-American communities, ultimately leaving many people unprotected. Disproportionate arrests in African-American communities for drug-related offenses has not only spread fear but also perpetuated a deep distrust for government and what some call racist drug enforcement policy. Additionally, a black-white disparity can be seen in probation revocation since black probationers were revoked at higher rates than white and Hispanic probationers in studies as published under the Urban Institute.
Sources: en.wikipedia.org
=== Military === Amid the blockade, American reconnaissance flights near Cuba increased. On 17 May, Axios reported classified U.S. intelligence that Cuba had acquired over 300 attack drones from Russia and Iran since 2023 and "recently began discussing plans" to attack the U.S. with them. Cuba described the case as "fraudulent" and a pretext for U.S. military action.
=== Pregnancy === Supplementation with a combination of vitamins E and C during pregnancy is not recommended by the World Health Organization. A Cochrane review concluded there was no support for the combination reducing risk of stillbirth, neonatal death, preterm birth, preeclampsia, or any other maternal or infant outcomes, either in healthy women or those considered at risk for pregnancy complications.
== Cited books == Mullenix, Matthew (2002). American Kestrels in Modern Falconry. Western Sporting Publications. ISBN 978-1-888357-05-9. Wauer, Roland H. (2005). The American kestrel: falcon of many names. Boulder, CO: Johnson Books. ISBN 978-1-55566-353-7.
Although it is a relatively immature area of research, it appears that heterotrimeric G-proteins may also take part in non-GPCR signaling. There is evidence for roles as signal transducers in nearly all other types of receptor-mediated signaling, including integrins, receptor tyrosine kinases (RTKs), cytokine receptors (JAK/STATs), as well as modulation of various other "accessory" proteins such as GEFs, guanine-nucleotide dissociation inhibitors (GDIs) and protein phosphatases. There may even be specific proteins of these classes whose primary function is as part of GPCR-independent pathways, termed activators of G-protein signalling (AGS). Both the ubiquity of these interactions and the importance of Gα vs. Gβγ subunits to these processes are still unclear. There are two principal signal transduction pathways involving the G protein-linked receptors: the cAMP signal pathway and the phosphatidylinositol signal pathway.
== Oxygen-14 == Oxygen-14 (half-life 70.62 seconds) is the second most stable radioisotope of oxygen, and decays by positron emission to nitrogen-14. Oxygen-14 ion beams are of interest to researchers of proton-rich nuclei; for example, one early experiment at the Facility for Rare Isotope Beams in East Lansing, Michigan, produced a 14O beam by proton bombardment of 14N, using it to determine the absolute strength of the electron capture transition.
Sources: en.wikipedia.org
Only a small number of early-stage human studies have been reported, and most were limited in size and duration. No large late-stage program has established a general efficacy or safety profile. The evidence base is therefore thin compared with approved medicines.
The peptide is listed as prohibited in competitive sport, so laboratories develop detection methods and monitor for its presence. Its appearance in enforcement reports reflects that classification rather than any approved athletic use. Analytical work in this area focuses on identifying the molecule and its breakdown products in biological samples.
Chromatographic separation combined with mass spectrometry identifies the peptide and estimates its amount in a sample. Testing can confirm whether the expected molecule is present and at what concentration. It cannot establish how a product was manufactured or whether it meets any purity standard.
It is a synthetic cyclic heptapeptide modelled on alpha-melanocyte-stimulating hormone. A lactam bridge links two side chains, forming a ring that stabilises the molecule against proteolysis. It belongs to the broader melanocortin peptide family.