The short version of cyclic heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-02-03 and is reviewed periodically as new material appears.
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.
Regulatory treatment of this peptide varies by country. It holds no marketing authorization as a medicine in the United States, the European Union, or most other jurisdictions. Some countries classify products containing it as prescription-only or unlicensed medicines, which restricts lawful supply. Authorities have issued public notices warning that unregulated products may contain undeclared or incorrect ingredients. The molecule also appears on prohibited lists for competitive sport. These measures address supply oversight rather than any approved therapeutic role.
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 |
|---|---|---|
| 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 |
Regulatory treatment varies by country. In the United States the peptide is not approved as a medicine, and products offered for human use may be treated as unapproved new drugs; some states also restrict sale. Australia, the United Kingdom, and European Union member states apply comparable restrictions to unapproved peptide products. Border agencies have seized shipments labelled as research chemicals. Classification may change over time, and the legal position for personal importation is not clearly settled in most published guidance.
Lyophilised melanotan-2 is supplied as a solid, which is more stable than a solution. The material is hygroscopic, so weighing is done quickly, in low humidity, with the container kept sealed. Reconstitution usually uses water for injection or bacteriostatic water, added down the wall of the vial to limit foaming. A reconstituted solution is held at 2 to 8 °C and kept away from light. Repeated freezing and thawing of the same vial is avoided because ice crystal formation and concentration effects degrade the peptide.
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.
Receptor-binding studies classify melanotan II as a non-selective melanocortin agonist. It interacts with MC1R, MC3R, MC4R and MC5R, with reported affinities in the low nanomolar range and no strong subtype preference. Activation of MC1R on dermal melanocytes shifts pigment synthesis toward eumelanin, the dark polymer deposited in melanosomes and transferred to keratinocytes. Because the same peptide engages MC4R in the hypothalamus, it also appears in animal work on food intake and erectile response, which is why it is discussed in both pigment and metabolic research. Which receptor populations dominate after systemic exposure in humans is not fully established.
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.
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.
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.
Cure T1D by restoring the body’s ability to produce insulin and stopping T1D before it occurs or providing insulin independence through replacement with insulin-producing cells. Improve lives by minimizing the effects of T1D as much as possible until new T1D resources, technologies, and therapies are discovered. Breakthrough T1D prioritizes four strategic research areas; autoimmune therapies, cell therapies, prevention of complications, and glucose control.
When the victorious Red Army again occupied Cossack districts in late 1919 and 1920, the Soviet regime did not officially reauthorize the implementation of de-Cossackization. There is, however, disagreement among historians as to the degree of Cossack's persecution by the Soviet regime. For example, the Cossack hosts were broken up among new provinces or autonomous republics. Some Cossacks, especially in areas of the former Terek host, were resettled so their lands could be turned over to natives displaced from them during the initial Russian and Cossack colonization of the area. At the local level, the stereotype that Cossacks were inherent counterrevolutionaries likely persisted among some Communist officials, causing them to target, or discriminate against, Cossacks despite orders from Moscow to focus on class enemies among Cossacks rather than the Cossack people in general.
S-(2-hydroxyacyl)glutathione + H2O = glutathione + a 2-hydroxy carboxylate This enzyme belongs to the family of hydrolases, specifically the class of thioester lyases. It is commonly known as glyoxalase II. It participates in pyruvate metabolism.
Drugs under prescription control are sent to pharmacies in multi-packs of unit packs or in bottles containing many hundreds of capsules. Typically a pharmacist prepares the final form of the unit pack or places a lower count of capsules in a small bottle for the customer. In a pharmacy, pharmacists are available to answer questions and to ensure that proper documentation is provided. Internet pharmacies mail the prescribed drugs to the customer; boxes or mailing envelopes are used. Child resistant packaging is often required on the unit packs; if requested, a pharmacist is allowed to put drugs in a bottle with easy-open features. Over-the-counter drugs are sold in independent or chain pharmacies, grocery stores, and diverse retail outlets. Usually the package needs to have all the usage information available. Packages often need to have tamper resistant features and child-resistant packaging. Usually the packaging and labeling of dietary supplements, homeopathic products, and folk medicines are not regulated. Some producers voluntarily follow the regulations for over-the-counter drugs or regional Pharmacopoeias.
=== Primary ion source === Three types of ion source are used for SSIMS: electron-impact ionization, surface ionization, or liquid-metal ion sources. In the electron-impact ion source, electrons from a heated filament (cathode) are accelerated towards an anode by a voltage difference where they ionize supply-gas atoms on impact. This source usually operates with noble gases. Typically, the energy is variable from 0.1–5 keV, allowing spot sizes from ~50 μm to several millimeters. Surface ionization sources use Cs+ as the primary beam sources for TOF SIMS. Evaporation of caesium from a heated tungsten surface occurs both as atoms and ions. These ions are then accelerated away from the emitting surface. Since no collisions are involved, the ion beam is very pure, and since evaporation is by thermal means, the energy spread is very small, ~2kT (0.2 eV). The low energy spread and high intrinsic brightness of the ion sources offers the possibility of obtaining small spot sizes. Liquid-metal ion sources draw a liquid metal (usually gallium or bismuth) from a heated reservoir over a tip (radius ≈5 μm) of a needle. An electrostatic field is produced at the tip by an extraction electrode biased negatively in front of the tip. Opposing electrostatic and surface-tension forces acting on the liquid film produce a conical shape with a high-radius-of-curvature cusp (≈2 μm) protruding from the tip. From this cusp field, ion emission occurs, by means of the process of field evaporation.
Sources: en.wikipedia.org
Chemical-based TTIs Most chemical reactions are well-described by the Arrhenius equation, which states that the rate of reaction increases exponentially as the temperature increases. This includes the abiotic (not by a living thing) degradation of most foods and drugs as well as many color-change chemical reactions, making them natural candidates for FHI. For temperatures at and above refrigeration, a common option to use an enzyme that catalyzes a color-changing chemical reaction: for example, a urease would convert urea to ammonia, which is basic and can trigger a color change in a pH indicator dye. The whole system can be put on a piece of filter paper. The permanganate/oxalate reaction is a potential alternative to costlier enzyme TTIs. A commercially used reaction (OnVu) involves photochromism. A photochromic spiropyran is first made to change color by "charging" with UV light; this changes it from colorless to blue. It would gradually return to the original white color as time passes, with the reaction accelerated by heat. Microbe-based TTIs The speed at which microbial food degradation happens are harder to describe using simple models from chemistry, as the growth of microbes involves thousands of chained chemical reactions. Microbes can also be used to cause color changes as their metabolism produce many products, so a microbe that causes color change can potentially be used to estimate the growth of spoilage bacteria. For example, lactic acid bacteria (LAB) is used to make many fermented foods such as kimchi.
A nuclear-weapon state with high military expenditure, India is among the world's largest economies and a founding member of the United Nations, while its cultural legacy encompasses 45 UNESCO World Heritage Sites. India's megadiverse land features four biodiversity hotspots. Its wildlife is supported in protected habitats and traditionally viewed with cultural tolerance.
== Medical and science == Computational Science, an academical research discipline Canadian Light Source, a synchrotron light source Clinical laboratory science, another name for Medical Technology or Medical Laboratory Science Combat lifesaver, US non-medical military role
Mass spectrometry imaging (MSI) is a technique used in mass spectrometry to visualize the spatial distribution of molecules, as biomarkers, metabolites, peptides or proteins by their molecular masses. After collecting a mass spectrum at one spot, the sample is moved to reach another region, and so on, until the entire sample is scanned. By choosing a peak in the resulting spectra that corresponds to the compound of interest, the MS data is used to map its distribution across the sample. This results in pictures of the spatially resolved distribution of a compound pixel by pixel. Each data set contains a veritable gallery of pictures because any peak in each spectrum can be spatially mapped. Despite the fact that MSI has been generally considered a qualitative method, the signal generated by this technique is proportional to the relative abundance of the analyte. Therefore, quantification is possible, when its challenges are overcome. Although widely used traditional methodologies like radiochemistry and immunohistochemistry achieve the same goal as MSI, they are limited in their abilities to analyze multiple samples at once, and can prove to be lacking if researchers do not have prior knowledge of the samples being studied. Most common ionization technologies in the field of MSI are DESI imaging, MALDI imaging, secondary ion mass spectrometry imaging (SIMS imaging) and Nanoscale SIMS (NanoSIMS).
NM-2-AI, or NM2AI, also known as N-methyl-2-aminoindane, is a stimulant of the 2-aminoindane family that has been sold online as a designer drug. It is a rigid analogue of methamphetamine. NM-2-AI acts as a selective norepinephrine releasing agent, but also has affinity for several monoamine receptors.
Sources: en.wikipedia.org
November 29 Twitter co-founder Jack Dorsey steps down as its chief executive, saying it is "finally time for me to leave". Parag Agrawal is named his successor. The Attorney General of New York Office releases lengthy documents which prove that CNN host Chris Cuomo abused journalistic ethics in a manner that was much greater than what had been reported earlier in the year. According to the documents, during Andrew Cuomo's sexual harassment scandal, Chris used his connections in the media both to obtain information about his brother's accusers as well as to uncover the possibility that new accusers could come out against the former New York governor. November 30 Former White House Chief of Staff Mark Meadows announces that he will testify to and cooperate with the January 6 committee. 2021 Oxford High School shooting – Four students are killed and seven other people are injured in a mass shooting at Oxford High School in Oxford Township, Michigan. CNN announces that it has indefinitely suspended Chris Cuomo while a law firm conducts an independent investigation that the network hired to look into the matter.
NADH-coenzyme Q oxidoreductase, also known as NADH dehydrogenase or complex I, is the first protein in the electron transport chain. Complex I is a giant enzyme with the mammalian complex I having 46 subunits and a molecular mass of about 1000 kDa. The structure is known in detail only from a bacterium; in most organisms the complex resembles a boot with a large "ball" poking out from the membrane into the mitochondrion. The genes that encode the individual proteins are contained in both the cell nucleus and the mitochondrial genome, as is the case for many enzymes present in the mitochondrion. The reaction that is catalyzed by this enzyme is the two electron oxidation of NADH by coenzyme Q10 or ubiquinone (represented as Q in the equation below), a lipid-soluble quinone that is found in the mitochondrion membrane:
Independence also did not result in stable political regimes, save in a few countries. First, the new nations did not have well-defined identities; rather, the process of creating identities was only beginning. This process would be carried out through newspapers and the creation of national symbols, including new names for the countries ("Mexico", "Colombia", "Ecuador", "Bolivia", "Argentina"), that broke with the past. In addition, the borders were not firmly established, and the struggle between federalism and centralism, which began in independence, continued throughout the rest of the century. Two large states that emerged from the wars—Gran Colombia and the Federal Republic of Central America—collapsed after a decade or two, and Argentina would not consolidate politically until the 1860s. The wars destroyed the old civilian bureaucracy that had governed the region for centuries, as institutions such as the audiencias were eliminated and many Peninsular officials fled to Spain. The Catholic Church, which had been an important social and political institution during the colonial period, initially came out weakened by the end of the conflicts. As with government officials, many Peninsular bishops abandoned their dioceses and their posts were not filled for decades until new prelates could be created and relations between the new nations and the Vatican were regularized. Then as the Church recovered, its economic and political power was attacked by liberals.
Despite the UN arms embargo on Bosnia, the ISI under General Javed Nasir airlifted anti-tank weapons and missiles to Bosnian mujahideen, shifting the tide in favour of Bosnian Muslims. ISI, under Nasir's leadership, supported Chinese Muslims in Xinjiang, rebel groups in the Philippines, and religious groups in Central Asia. Since 2001, the Pakistan military has been engaged in counterinsurgency and internal security operations in the Khyber Pakhtunkhwa province, primarily targeting Tehrik-e-Taliban Pakistan and associated militant groups. Major military operations conducted during this period include Operation Enduring Freedom, Operation al-Mizan, Operation Zalzala, Operation Sherdil, Operation Rah-e-Haq, Operation Rah-e-Rast, and Operation Rah-e-Nijat.
Liberation – How is the active pharmaceutical ingredient disintegrated (for solid oral forms (breaking down into smaller particles), dispersed, or dissolved from the medication? Absorption – How is the active pharmaceutical ingredient absorbed (through the skin, the intestine, the oral mucosa)? Distribution – How does the active pharmaceutical ingredient spread through the organism? Metabolism – Is the active pharmaceutical ingredient converted chemically inside the body, and into which substances. Are these active (as well)? Could they be toxic? Excretion – How is the active pharmaceutical ingredient excreted (through the bile, urine, breath, skin)? Drug metabolism is assessed in pharmacokinetics and is important in drug research and prescribing. Pharmacokinetics is the movement of the drug in the body, it is usually described as 'what the body does to the drug' the physico-chemical properties of a drug will affect the rate and extent of absorption, extent of distribution, metabolism and elimination. The drug needs to have the appropriate molecular weight, polarity etc. in order to be absorbed, the fraction of a drug that reaches the systemic circulation is termed bioavailability, this is simply a ratio of the peak plasma drug levels after oral administration and the drug concentration after an IV administration (first pass effect is avoided and therefore no amount drug is lost). A drug must be lipophilic (lipid soluble) in order to pass through biological membranes because biological membranes are made up of a lipid bilayer (phospholipids etc.).
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 and an analogue of alpha-melanocyte-stimulating hormone. The molecule is produced by chemical synthesis rather than extracted from a biological source.