Everything below concerns alpha-MSH. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-04-21. Where a claim depends on a specific study, the study is described rather than over-claimed.
The material is commonly handled as a lyophilized powder in sealed vials. The solid dissolves readily in water and in polar organic solvents, producing a clear solution after reconstitution. Light, heat and repeated freeze-thaw cycles are the concerns most often raised in handling guidance, because peptide bonds and the constrained ring can degrade. Working solutions are generally prepared fresh, and material left in solution is treated as less stable than the dry form. These properties shape how laboratories store and aliquot reference material.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Retention time supports identity, while the mass spectrum confirms the molecular weight of the intact peptide. Purity is frequently reported as a percentage of total peak area, a figure that depends on the wavelength, column and gradient used. Impurity profiling may also look for truncated sequences, oxidised forms and residual counterions. Amino acid analysis and peptide mapping provide orthogonal confirmation when required.
The peptide was developed during the 1980s by researchers investigating melanocortin signalling and skin pigmentation pathways. Early work focused on analogues of alpha-melanocyte-stimulating hormone that would resist enzymatic breakdown more effectively than the parent molecule. Melanotan-2 emerged from that programme as a shortened, cyclised variant. Reports describing its synthesis and receptor activity later appeared in the scientific literature. Commercial availability grew through unregulated channels rather than through pharmaceutical approval.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Typically supplied as a lyophilized solid in a sealed vial |
| Solubility class | Soluble in water and polar organic solvents | Reconstituted solutions are generally clear |
| Typical storage temperature | -20 degrees Celsius or below, dry | Protect from light; avoid repeated freeze-thaw cycles |
| Common analytical methods | Reversed-phase HPLC-UV, LC-MS | Used for purity estimation and mass confirmation |
| Reported purity range | Area percentage above 95 percent | Reporting practice and acceptance limits differ by laboratory |
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.
The peer-reviewed record is dominated by small early-phase studies, case reports and pharmacovigilance summaries rather than large randomised trials. Papers typically examine tanning response, receptor selectivity or patterns of reported adverse events. Many note that participants obtained the peptide outside a clinical setting, which limits verification of composition and administered amount. Reported events vary widely, and causality is frequently unclear because the identity and purity of self-sourced material are unknown. Open questions include whether repeated melanocortin receptor stimulation produces cumulative effects, and how often label claims match actual content.
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.
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.
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.
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.
Identity and purity are usually assessed by reversed-phase high-performance liquid chromatography, which separates the target peptide from truncated or oxidised impurities. Mass spectrometry, most often coupled to liquid chromatography, confirms molecular mass and detects substitutions that chromatography alone may miss. Amino acid analysis and peptide mapping supply additional structural evidence, while nuclear magnetic resonance is reserved for full structural confirmation. Laboratories that examine samples sold online report wide variation in actual content, with some vials containing little or none of the labelled material.
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.
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.
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.
== History == SJS is named for Albert Mason Stevens and Frank Chambliss Johnson, American pediatricians who jointly published a description of the disorder in the American Journal of Diseases of Children in 1922.
== Proteins which contain the ICK motif == Agouti related peptide Agouti signalling peptide Albumin I Covalitoxin-II DkTx Grammotoxin GsMTx-4 Guangxitoxin Hainantoxin Hanatoxin Heteroscodratoxin-1 Huwentoxin Maurocalcine Theraphosa leblondi toxin δ-Palutoxin Phrixotoxin Psalmotoxin Robustoxin Stromatoxin Tachystatin Vanillotoxin Vejocalcin
The district features many buildings in Art Nouveau, Art Deco and Neo-Gothic style. Among them, one of the most impressive and well known is the Casa della Vittoria (architect Gottardo Gussoni). Another notable example is Casa Fenoglio-Lafleur. Both buildings face Corso Francia. The district is well known for its commercial vocation mainly in its two main streets, Via Duchessa Jolanda and Via Principi d'Acaja, ideally crossing each other among the gardens Giardino Luigi Martini, locally called Piazza Benefica, which hosts a popular open market. The district is also characterised by two massive recent buildings: the Palazzo di Giustizia, Turin's new courthouse built in the 1990s (in a 350-metre-long facility), and the first real skyscraper of Turin, the Torre Intesa Sanpaolo, which house the headquarters of one of the major Italian private banks.
== Biosafety == Xenobiological systems are designed to convey orthogonality to natural biological systems. A (still hypothetical) organism that uses XNA, different base pairs and polymerases and has an altered genetic code will hardly be able to interact with natural forms of life on the genetic level. Thus, these xenobiological organisms represent a genetic enclave that cannot exchange information with natural cells. Altering the genetic machinery of the cell leads to semantic containment. In analogy to information processing in IT, this safety concept is termed a "genetic firewall". The concept of the genetic firewall seems to overcome a number of limitations of previous safety systems. A first experimental evidence of the theoretical concept of the genetic firewall was achieved in 2013 with the construction of a genomically recoded organism (GRO). In this GRO all known UAG stop codons in E.coli were replaced by UAA codons, which allowed for the deletion of release factor 1 and reassignment of UAG translation function. The GRO exhibited increased resistance to T7 bacteriophage, thus showing that alternative genetic codes do reduce genetic compatibility. This GRO, however, is still very similar to its natural "parent" and cannot be regarded to have a genetic firewall. The possibility of reassigning the function of large number of triplets opens the perspective to have strains that combine XNA, novel base pairs, new genetic codes, etc. that cannot exchange any information with the natural biological world.
Sources: en.wikipedia.org
=== Concerns of use === As of 2016, it is unknown what the impacts of nano-sized materials are to human health and the environment. It is only via chemical risk and toxic assessments over time can affirm any effects. The measures for testing are currently insufficient, and the approval for the use of nanoparticles, especially in food, is ambiguous.
Benorterone, also known as 17α-methyl-B-nortestosterone or as 17α-methyl-B-norandrost-4-en-17β-ol-3-one, is a synthetic androstane steroid and a derivative of testosterone. Specifically, it is the C17α methyl and B-nor analogue of testosterone and the B-nor analogue of methyltestosterone. Other testosterone-derived steroidal antiandrogens include abiraterone acetate, BOMT, delanterone, dienogest, galeterone, metogest, mifepristone, oxendolone, rosterolone, topterone, trimethyltrienolone, and zanoterone, while progesterone-derived steroidal antiandrogens include examples like cyproterone and cyproterone acetate.
4-Hydroxytryptamine (4-HT, 4-HTA), also known as N,N-didesmethylpsilocin, is a naturally occurring tryptamine alkaloid. It is closely related chemically to the neurotransmitter serotonin, the psychedelic psilocin, and is the active form of the tryptamine alkaloid norbaeocystin. The compound is a serotonin receptor agonist, including of the serotonin 5-HT2A receptor, but in contrast to certain closely related compounds like psilocin, appears to be non-hallucinogenic. 4-HT may occur naturally in Psilocybe baeocystis and Psilocybe cyanescens. It may serve as an alternative precursor in the biosynthesis of psilocybin (4-PO-DMT) in psilocybin mushrooms.
Sources: en.wikipedia.org
The dry powder is more stable during transport and storage than a solution. It also allows a known amount of material to be reconstituted at a chosen concentration.
Most certificates state a percentage derived from chromatographic peak area, alongside a mass confirmation. The exact criteria and acceptance thresholds vary between laboratories.
Dry powder is kept frozen or refrigerated and protected from light and moisture. Solutions are handled cold and used promptly to limit degradation.
It is a synthetic cyclic heptapeptide and an analogue of alpha-melanocyte-stimulating hormone. The molecule is produced by chemical synthesis rather than extracted from a biological source.