A practical reference on Alpha-MSH: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-06 and is reviewed periodically as new material appears.
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.
Routine characterisation relies on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, using a C18 column and a water-acetonitrile gradient containing trifluoroacetic acid. Electrospray ionisation mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidised by-products that co-elute poorly. Sequence and stereochemistry require additional work, such as peptide mapping or amino acid analysis, because a chromatographic purity figure alone does not distinguish a diastereomer from the target peptide. Independent testing of research-grade material frequently shows measured content below the stated label, so a certificate of analysis is best read together with the method that produced it.
Melanotan-2 is handled in the laboratory as a lyophilised powder that dissolves readily in water, dimethyl sulfoxide and dimethylformamide, with limited solubility in ethanol. Stock solutions prepared in an organic solvent often precipitate when diluted into aqueous buffer, so gradual dilution with mixing is standard practice. The peptide carries a tryptophan residue and a histidine residue, both sensitive to oxidation and to alkaline conditions. Working solutions are therefore kept near neutral to slightly acidic pH, protected from light, and consumed within the same working session whenever that is practical.
Solid peptide kept dry at minus twenty degrees Celsius, shielded from light and moisture, is generally considered stable for extended periods. Solutions are divided into single-use aliquots and held at minus twenty or minus eighty degrees Celsius, because repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. Hydrolysis of the backbone and oxidation of tryptophan are the principal degradation routes in aqueous solution, and both accelerate at ambient temperature. Hygroscopic uptake after a vial is opened can also shift the actual mass weighed, which affects any concentration calculated from it.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | Melanotan II; MT-II; N-acetyl-norleucyl-cyclo[Asp-His-D-Phe-Arg-Trp-Lys] amide | Naming follows peptide convention; the numeral distinguishes it from melanotan-1 |
| Molecular formula | C50H69N15O9 | Includes the lactam bridge; no counter-ion assumed |
| Monoisotopic mass | 1023.53 Da | Free base; salts and counter-ions shift the observed value |
| Appearance | White to off-white lyophilised powder | Batch-to-batch colour variation is not itself proof of impurity |
| Typical analytical method | RP-HPLC purity determination with ESI-MS identity confirmation | Retention time alone does not establish sequence identity |
Activity is attributed to agonism at melanocortin receptors, particularly MC1R and MC4R. Activation of MC1R on melanocytes increases melanin synthesis, which underlies the reported tanning effect. MC4R engagement in the central nervous system is linked to appetite suppression and to effects on sexual arousal reported in early clinical studies. Those studies were small and were not designed to establish efficacy or long-term safety. Receptor selectivity among the melanocortin subtypes is not absolute, which complicates attribution of any effect to a single pathway.
Regulatory treatment varies between countries. Several national medicines agencies have classified the peptide as unapproved, and customs authorities in some jurisdictions seize shipments on that basis. A few jurisdictions channel supply through prescription-only frameworks that do not list the substance by name. Because the material circulates mainly through online vendors, composition and purity are rarely verified before sale. Surveys of unapproved peptide products have reported labels that did not match measured content in a substantial fraction of samples.
Melanotan II is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its structure substitutes a lactam bridge between side chains to increase stability relative to the native hormone. The compound is also known by the shorthand MT-II and by several non-proprietary synonyms used in research catalogues. It is not an approved therapeutic product in any major jurisdiction; material sold under this name is typically offered as a laboratory reagent rather than as a medicine.
Melanotan-2 appears on the World Anti-Doping Agency prohibited list within the peptide hormone class, and several national regulators treat it as an unapproved prescription substance. Some countries restrict importation or sale for personal use. Because the compound is widely traded as a research chemical, the practical legal picture differs between jurisdictions and shifts over time. Human safety data covering long periods are limited, and whether repeated pigmentation changes carry any lasting risk to melanocytes remains an open question.
Freeze-dried melanotan-2 is normally kept as a desiccated powder at minus twenty degrees Celsius or lower, shielded from light and moisture. Peptides of this size degrade through hydrolysis, oxidation and deamidation, and each pathway accelerates as temperature and water activity rise. Repeated freeze-thaw cycles promote aggregation and loss of material, so aliquoting a stock solution before freezing is standard laboratory practice. Once dissolved, the solution is markedly less stable than the powder. In laboratory work, solutions are generally refrigerated and used within days rather than kept for months.
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.
Early published reports described melanotan-2 as a tanning agent without sun protection, which means darkening is not the same as protection against ultraviolet radiation. Later studies explored the peptide in erectile dysfunction, hemorrhagic shock, and some skin conditions. No regulator in the United States or Europe has approved it for clinical use. Many products labelled melanotan-2 are sold without approval and their identity and purity are unverified. Its long-term safety in humans remains an open question.
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.
== Pharmacology == Since pembrolizumab is cleared from the circulation through non-specific catabolism, no metabolic drug interactions are expected and no studies were done on routes of elimination. The systemic clearance [rate] is about 0.2 L/day and the terminal half-life is about 25 days.
==== Employee opposition to AI militarisation ==== In May 2026, workers at Google DeepMind's London headquarters voted to unionise, requesting joint representation by the Communication Workers Union (CWU) and Unite the Union. The unionisation drive was heavily motivated by ethical concerns regarding Google's military-industrial AI contracts, specifically the provision of AI technology to the US Department of Defense and the Israeli military.
By the second half of the 1800s, the scientific study of psychology was becoming well established in university laboratories. Although there were a few scattered voices calling for applied psychology, the general field looked down upon this idea and insisted on "pure" science as the only respectable practice. This changed when Lightner Witmer (1867–1956), a past student of Wundt and head of the psychology department at the University of Pennsylvania, agreed to treat a young boy who had trouble with spelling. His successful treatment was soon to lead to Witmer's opening of the first psychological clinic at Penn in 1896, dedicated to helping children with learning disabilities. Ten years later in 1907, Witmer was to found the first journal of this new field, The Psychological Clinic, where he coined the term "clinical psychology", defined as "the study of individuals, by observation or experimentation, with the intention of promoting change". The field was slow to follow Witmer's example, but by 1914, there were 26 similar clinics in the US. Even as clinical psychology was growing, working with issues of serious mental distress remained the domain of psychiatrists and neurologists. However, clinical psychologists continued to make inroads into this area due to their increasing skill at psychological assessment. Psychologists' reputation as assessment experts became solidified during World War I with the development of two intelligence tests, Army Alpha and Army Beta (testing verbal and nonverbal skills, respectively), which could be used with large groups of recruits.
Acetorphine is a potent opioid analgesic, up to 8700 times stronger than morphine by weight. It is a derivative of the more well-known opioid etorphine, which is used as a very potent veterinary painkiller and anesthetic medication, primarily for the sedation of large animals such as elephants, giraffes and rhinos. Acetorphine was developed in 1966 by the Reckitt research group that developed etorphine. Acetorphine was developed for the same purpose as etorphine itself, namely as a strong tranquilizer for use in immobilizing large animals in veterinary medicine. Despite showing some advantages over etorphine, for instance producing less toxic side effects in giraffes, acetorphine was never widely adopted for veterinary use, and etorphine (along with other tranquilizers such as carfentanil and azaperone) remains the drug of choice in this application.
Training, HRD and R&D Committee. Committee for Strengthening Supply Chain & Logistics. Application of Non-conventional Energy Sources in Cold Chain Infrastructure. Technical Specification, Standards, Test Laboratory and Product Certification Committee. These committees contribute towards this nodal body's functioning along its road-map.
Sources: en.wikipedia.org
=== Reality television === There are programs specifically dedicated to showcasing the lives and resulting struggles of people experiencing specific mental illnesses. For example, the hit television show on the A&E network, Hoarders, showcases one or two individuals and their obsessive-compulsive disorder. Throughout an episode, each individual works with a psychologist or psychiatrist, professional organizer, or an "extreme cleaning specialist" specializing in treating this disorder. Another program on the A&E network, Intervention, introduces audiences to people dealing with substance abuse. This program, in a similar format to Hoarders, follows the story of either one or two individuals who suffer from substance dependence. During an episode, the audience follows the individuals' daily lives and is introduced to the reality of living with this dependence. The individuals are then confronted with an ultimatum in which they must decide whether to seek rehabilitation or risk losing family, friends, shelter, and, in most cases, financial assistance. This documentary-style television program is valuable because it educates viewers about the entire intervention process, from being introduced to the intervention process itself to the proper way to handle an individual with addiction. It also effectively decreases the stigma of therapy and demonstrates the effectiveness of interventions.
== Health benefits == In the absence of liver disease, high levels of total bilirubin confers various health benefits. Studies have also revealed that levels of serum bilirubin (SBR) are inversely related to risk of certain heart diseases. While the poor solubility and potential toxicity of bilirubin limit its potential medicinal applications, current research is being done on whether bilirubin encapsulated silk fibrin nanoparticles can alleviate symptoms of disorders such as acute pancreatitis. In addition to this, there have been recent discoveries linking bilirubin and its ε-polylysine-bilirubin conjugate (PLL-BR), to more efficient insulin medication. It seems that bilirubin exhibits protective properties during the islet transplantation process when drugs are delivered throughout the bloodstream.
=== Pharmacodynamics === Oliceridine is a μ-opioid receptor biased agonist developed by Trevena. In cell-based (in vitro) research, oliceridine elicits robust G protein signaling, with potency and efficacy similar to that of morphine, but with less β-arrestin 2 recruitment and receptor internalization. It has been suggested that this might be due to its low intrinsic efficacy, rather than functional selectivity or 'G protein bias', although the validity of that conclusion has also been questioned. In vivo, it may have fewer adverse effects (including respiratory depression and constipation) compared with morphine. In general, in vitro potency does not guarantee any clinical relevance in humans.
== Pharmacokinetics in comparison to other lithium salts == In 1973, Hans Nieper reported that lithium orotate contained 3.83 mg of elemental lithium per 100 mg and lithium carbonate contained 18.8 mg of elemental lithium per 100 mg. Nieper went on to claim that lithium did not dissolve from the orotate carrier until it passed through the blood–brain barrier; however, a 1976 study documented that lithium concentrations within the brains of rats were not statistically different between equivalent dosages of lithium from lithium orotate, lithium carbonate, or lithium chloride. However, another study in 1978 showed that eight hours after intraperitoneal injections brain lithium concentrations of rats were significantly greater after lithium orotate than after lithium carbonate. While little serum lithium remained at 24 h after injection of 2·0 m equiv kg−1 lithium carbonate, two‐thirds of the 2 h serum lithium concentration was present 24 h after lithium orotate. Furthermore, the 24 h brain concentration of lithium after lithium orotate was approximately three times greater than that after lithium carbonate.
Sources: en.wikipedia.org
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.
The natural hormone is a linear tridecapeptide that is rapidly degraded in circulation. Melanotan-2 is shortened, cyclised, N-terminally acetylated, and carries a D-amino acid substitution, all of which slow enzymatic breakdown.
No national medicines regulator has approved melanotan-2 for therapeutic or cosmetic use. In several jurisdictions it is treated as an unapproved prescription medicine, and its legal classification differs from country to country.
Purity is normally stated as an area percentage from high-performance liquid chromatography, for example ninety-five or ninety-eight percent. That figure describes the proportion of ultraviolet-absorbing material eluting as the main peak. It says nothing about water content, counterions, residual solvents or mass fraction of the peptide itself.