prohibited list raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2025-08-23. Anything still debated is marked as such rather than presented as settled.
The compound was developed in the late 1980s and early 1990s by academic researchers investigating melanocortin signaling and pigmentation. Early work explored whether synthetic analogs could reproduce effects of the natural hormone under controlled conditions. The molecule never advanced through the full regulatory pathway required for approval as a medicine. From the mid-2000s onward it appeared in unregulated consumer markets, often distributed through informal channels. That gap between research origins and commercial availability shapes how the compound is discussed today.
Melanotan-2 is a synthetic peptide designed as an analog of alpha-melanocyte-stimulating hormone, a signaling molecule produced in the pituitary and skin. Its structure is a linear chain of seven amino acids that folds into a ring through an internal lactam bridge joining two side chains. The compound is sometimes written as MT-II or MEL-2 in informal and commercial contexts. It belongs to the melanocortin peptide family, a group of short signaling molecules that share a conserved core sequence recognized by melanocortin receptors.
Scientific discussion of Melanotan-2 spans pharmacology, dermatology, and public-health literature. Laboratory studies examine its receptor binding and cellular effects, while clinical reports describe outcomes observed after unregulated use. These two bodies of work differ in rigour and intent. Peer-reviewed trials of the compound as a medicine are limited, so much of the available information comes from case reports and surveillance data. Authors frequently note the gap between experimental findings and real-world use.
Reported observations after unregulated use include shifts in skin pigmentation and, in some accounts, unintended changes to moles and other lesions. Whether these outcomes are causally linked to the compound, and how often they occur, remain open questions because controlled data are scarce. The absence of standardised dosing and verified product purity complicates interpretation. Researchers have called for better surveillance and analytical characterisation of samples obtained outside regulated channels. Conclusions drawn from anecdotal evidence should be treated as provisional.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic cyclic heptapeptide | Analog of alpha-MSH with an internal lactam bridge |
| Molecular weight | Approximately 1024 daltons | Free base value; salt forms differ |
| Appearance | White to off-white powder | Usually supplied as a lyophilized solid |
| Solubility | Freely soluble in water | Poorly soluble in nonpolar solvents |
| Typical storage | −20 °C, dry, protected from light | Repeated freeze-thaw cycles degrade peptides |
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.
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.
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.
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.
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.
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.
Ion-exchange chromatography (IEC) or ion chromatography (IC) is an analytical technique for the separation and determination of ionic solutes in aqueous samples from environmental and industrial origins such as metal industry, industrial waste water, in biological systems, pharmaceutical samples, food, etc. In IEC, there are electrically charged sites bound to the stationary phase. Solute ions charged the same as the ions on the column are repulsed and elute without retention, while solute ions charged oppositely to the charged sites of the column are retained on it. In general, ions of higher charge and smaller radius are more strongly retained. Solute ions that are retained on the column can be eluted from it by changing the mobile phase composition, such as increasing its salt concentration and pH, or increasing the stationary phase temperature, etc. Types of ion exchangers include polystyrene resins, cellulose and dextran ion exchangers (gels), and controlled-pore glass or porous silica gel. Polystyrene resins allow cross linkage, which increases the stability of the chain. Higher cross linkage reduces swerving, which increases the equilibration time and ultimately improves selectivity. Cellulose and dextran ion exchangers possess larger pore sizes and low charge densities making them suitable for protein separation. An increase in counter ion (with respect to the functional groups in resins) concentration reduces the retention time, as it creates a strong competition with the solute ions.
== Genetics == Human factor XIII consist of A and B subunits. A subunit gene is F13A1. It is on chromosome 6 at the position 6p24–25. It spans over 160 kbp, has 14 introns and 15 exons. Its mRNA is 3.9 kbp. It has a 5' UTR of 84 bp and a 3' UTR of 1.6 kbp. F13A1 exon(s)
Xylazine is the most widely anesthetic agent used for short-duration operations in non-human animals. It does not have a medical use in humans. Pharmacokinetics of xylazine may be influenced by anesthesia since after an intravenous therapy about 1.1 mg/kg, the half-life of xylazine will increase to 118 minutes and the clearance will decrease to 6 mL/kg/min. Based on a recent study, if injecting the morphine, which is 0.1 or 0.2 mg/kg, in the vein at the same time can extend the terminal half-life to about 150 minutes and the clearance will not be influenced.
=== Pharmacodynamics === Gepirone acts as a selective partial agonist of the 5-HT1A receptor. Unlike its relative buspirone, however, gepirone has greater efficacy in activating the 5-HT1A and has negligible affinity for the D2 receptor (30- to 50-fold lower in comparison to buspirone). However, similarly to buspirone, gepirone metabolizes into 1-(2-pyrimidinyl)piperazine (1-PP), which is known to act as a potent antagonist of the α2-adrenergic receptor. Gepirone has been found to produce antiaggressive effects in rodents.
Sources: en.wikipedia.org
== Applications == Ligand binding assays provide a measure of the interactions that occur between two molecules, such as protein-bindings, as well as the degree of affinity (weak, strong, or no connection) for which the reactants bind together. Essential aspects of binding assays include, but are not limited to, the concentration level of reactants or products (see radioactive section), maintaining the equilibrium constant of reactants throughout the assay, and the reliability and validity of linked reactions. Although binding assays are simple, they fail to provide information on whether or not the compound being tested affects the target's function.
An essential amino acid is an amino acid that is required by an organism but cannot be synthesized de novo by it, and therefore must be supplied in its diet. Out of the twenty standard protein-producing amino acids, nine cannot be endogenously synthesized by humans: phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine.
== Chemistry == The three major chemical groups of serotonergic psychedelics include the tryptamines, phenethylamines, and lysergamides, which each have different profiles of pharmacological activity. A number of other miscellaneous structural groups also exist.
Field rations can be eaten at any temperature, but are preferably heated or cooked. However, as the use of cooking appliances or fire may be unavailable or tactically unwise, smokeless solid fuel and a portable stove are typically included in rations to heat meals. Hexamine fuel tablets have traditionally been preferred, though gelatinized ethanol is also sometimes used. Some modern field rations use a flameless ration heater instead of fuel tablets. NATO standardization states that, while main courses and entrées must be consumable without heating, main course components and hot beverages should be provided with a heater, with such items intended to be heated to a minimum temperature of 62 °C from an ambient temperature of 20 °C within 12 minutes.
A syringe is a simple reciprocating pump consisting of a plunger (though in modern syringes, it is actually a piston) that fits tightly within a cylindrical tube called a barrel. The plunger can be linearly pulled and pushed along the inside of the tube, allowing the syringe to take in and expel liquid or gas through a discharge orifice at the front (open) end of the tube. The open end of the syringe may be fitted with a hypodermic needle, a nozzle or tubing to direct the flow into and out of the barrel. Syringes are frequently used in clinical medicine to administer injections, infuse intravenous therapy into the bloodstream, apply compounds such as glue or lubricant, and draw/measure liquids. There are also prefilled syringes (disposable syringes marketed with liquid inside). The word "syringe" is derived from the Greek σῦριγξ (syrinx, meaning "Pan flute", "tube").
Sources: en.wikipedia.org
=== In the food industry === In the food industry, tyrosinase inhibition is desired as tyrosinase catalyzes the oxidation of phenolic compounds found in fruits and vegetables into quinones, which gives an undesirable taste and color and also decreases the availability of certain essential amino acids as well as the digestibility of the products. As such, highly effective tyrosinase inhibitors are also needed in agriculture and the food industry. Well known tyrosinase inhibitors include kojic acid, tropolone, coumarins, vanillic acid, vanillin, and vanillic alcohol.
== Development == In 1987 antistasin was tested as the first direct Xa inhibitor. Antistasin is a protein made up of 119 amino acid residues, of which 20 are cysteines involved in 10 disulfide bonds. It acts as a slow, tight-binding inhibitor of factor Xa with a Ki value of 0.3–0.6 nM but it also inhibits trypsin. Recombinant Antistasin can be produced by genetically modified yeast, saccharomyces cerevisiae. Another natural occurring direct Xa-inhibitor, the tick anticoagulant peptide (TAP), was discovered in 1990. It is a single-chain, 60 amino acid peptide and like antistasin it is a slow, tight-binding inhibitor with a similar Ki value (~0.6 nM). These two proteins were mostly used to validate factor Xa as a drug target. Animal studies suggested direct Xa-inhibition to be a more efficient approach to anticoagulation compared to direct thrombin inhibitors, especially offering a wider therapeutic window and reducing the risk of rebound thrombosis, (increase in thromboembolic events occurring shortly after the withdrawal of an antithrombotic medication) compared to direct and indirect thrombin inhibitors. During the 1990s several low-molecular-weight substances were developed, such as DX-9065a and YM-60828.
Noriega received several warnings about the invasion from individuals within his government; though he initially disbelieved them, they grew more frequent as the invasion drew near, eventually convincing Noriega to go on the run. Noriega used a number of subterfuges, including lookalikes and playbacks of his recorded voice, to confuse U.S. surveillance as to his whereabouts. During his flight, Noriega reportedly took shelter with several supportive politicians, including Balbina Herrera, the mayor of San Miguelito. The last two days of his flight were spent partly with his ally Jorge Krupnick, an arms dealer also wanted by the U.S. Kempe reported that Noriega considered seeking sanctuary in the Cuban or Nicaraguan embassies, but both buildings were surrounded by U.S. troops. On the fifth day of the invasion, Noriega and four others took sanctuary in the Apostolic Nunciature, the Holy See's embassy in Panama. Having threatened to flee to the countryside and lead guerrilla warfare if not given refuge, he instead turned over the majority of his weapons, and requested sanctuary from Archbishop José Sebastián Laboa, the papal nuncio. Prevented by treaty from invading the Holy See's embassy, U.S. soldiers from Delta Force and part of Operation Nifty Package erected a perimeter around the Nunciature. Attempts to dislodge Noriega from within included gunning vehicle engines, turning a nearby field into a landing pad for helicopters, and playing rock music at loud volumes (a Van Halen cassette tape was provided by Special Forces Sergeant John Bishop).
Because this process removes/inactivates the lipid coating of a virus, viruses without any sort of lipid envelope will be unaffected. There is also no inactivation effect by the buffers used in this process.
== History == The first ion funnel was created in 1997 in the Environmental Molecular Sciences Laboratory Pacific Northwest National Laboratory by the researchers in Richard D. Smith's lab. The ion funnel was implemented to replace the ion transmission-limited skimmer for more efficient ion capture in an ESI source. Many characteristics of the ion funnel are attributed to the stacked ring ion guide, however, the disks of an ion funnel vary in diameter down its long axis. There is a portion at the base of the ion funnel in which a series of cylindrical ring electrodes have decreasing diameters, which enables the ion cloud entering the ion funnel to be spatially dispersed. This allows for efficient transfer of the ion cloud through the conductance limiting orifice at the exit as the ion cloud becomes focused to a much smaller radial size. The DC electric field serves to push ions through the funnel. For positive ions, the front plate of the funnel has the most positive DC voltage, and subsequent plates have gradually decreasing DC components, providing added control. RF and DC electric fields are co-applied with a pseudopotential created with alternating RF polarities on adjacent electrodes. This “pseudo-potential” radially confines ions and causes instability in ions with a lower m/z (mass to charge ratio) while ions with a higher m/z are focused to the center of the funnel. The initial ion funnel design used in the Smith research lab proved inefficient for collecting ions with low m/z.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide modeled on alpha-melanocyte-stimulating hormone. It carries two non-natural substitutions and a cyclic bridge that increase its stability relative to the natural hormone. It circulates as a research chemical and is not an approved medicine.
Melanotan-1, also called afamelanotide, is a shorter linear analog with a different amino acid sequence and no lactam ring. It has been evaluated in formal clinical programs, while melanotan-2 has not. The two are distinct molecules and are not interchangeable.
No. Bremelanotide is a related but distinct cyclic peptide that reached approved status for one specific clinical indication. Melanotan-2 is a separate molecule with its own sequence and properties. Shared ancestry in the melanocortin family does not make them the same substance.
Major regulatory agencies have not approved it for any indication. Some countries permit it only under prescription frameworks, while others classify it as a controlled substance.