Everything below concerns alpha-MSH analogue. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-04-21. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 |
|---|---|---|
| Typical storage temperature | -20 °C or below | For the lyophilised powder, desiccated |
| Storage form | Sealed vial, protected from light | Amber glass or foil-wrapped containers |
| Reconstituted stability | Short, refrigerate | Degradation accelerates in solution |
| Typical analytical method | Reversed-phase HPLC with mass spectrometry | Purity assessment plus identity confirmation |
| Common synonyms | Melanotan II, MT-II | Also written melanotan-2 |
Regulatory treatment varies by country. In the United States, melanotan-2 is not approved for any indication, and products marketed for human use fall outside the approved drug framework. Some other jurisdictions have placed it under prescription controls or listed it as a prohibited or restricted substance. Online listings frequently describe the material as a research chemical, a category that does not carry the same manufacturing and labelling requirements as approved medicines.
Solid peptide material is generally stable when kept cold and dry. Common practice is storage at -20 degrees Celsius or lower, with desiccant and protection from light. Repeated freeze-thaw cycles and exposure to moisture are associated with degradation, aggregation, or loss of material. Once dissolved, stability depends on solvent, concentration, and temperature, and solutions are usually treated as short-lived unless stability data support longer periods. Handling notes typically emphasise minimising time at ambient temperature.
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.
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.
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.
== See also == Acetyl hexapeptide-3 BPC-157 CyRL-QN15 Glutathione Glycyl-prolyl-hydroxyproline KPV tripeptide Matrikine Palmitoyl pentapeptide-4 Silk peptides Small copper carrier unknown but heavier molecule TB-500
As a bifunctional molecule, glycine reacts with many reagents. These can be classified into N-centered and carboxylate-center reactions. Glycine functions as a bidentate ligand for many metal ions, forming amino acid complexes. Representative complexes include iron glycinate, copper glycinate, and zinc glycinate. With acid chlorides, glycine converts to the amidocarboxylic acid, such as hippuric acid and acetylglycine. With nitrous acid, one obtains glycolic acid (van Slyke determination). With methyl iodide, the amine becomes quaternized to give trimethylglycine, a natural product:
=== Primary prevention === Primary prevention aims to reduce the risk factors before a disease or condition occurs. Sun protection is the most effective form of primary prevention of photoaging. The major methods of sun protection are sunscreen products, sun protective clothing, and reducing exposure to the sun, especially during peak sun hours (10 AM-4 PM in the spring and summer seasons). Broad-spectrum sunscreen products provide optimal coverage for protection against UV damage because they protect against both types of UVA rays (UVA1 and UVA2) along with UVB rays. Proper application methods and timing are important factors in proper sunscreen use. This includes using a proper quantity of sunscreen, applying sunscreen prior to sun exposure, and consistent reapplication (especially after exposure to water or sweat).
=== Fish glue === Fish glue is made from the bones or tissues of fish. Isinglass is made specifically from the swim bladders, and is collagen-based. Fish glues were used in Ancient Egypt and Classical Antiquity in the Mediterranean; they continued to be used in Europe in Late Antiquity and the Medieval period, and are still used in niche applications today. It is brittle when dried, so it has sometimes been mixed with plasticizers such as molasses and honey. It was used in art, book binding, woodworking, lutherie, and for gluing paper and bone.
Oxycodone is the most widely recreationally used opioid in America. In the United States, more than 12 million people use opioid drugs recreationally. The U.S. Department of Health and Human Services estimates that about 11 million people in the U.S. consume oxycodone in a non-medical way annually. Opioids were responsible for 49,000 of the 72,000 drug overdose deaths in the U.S. in 2017. In 2007, about 42,800 emergency room visits occurred due to "episodes" involving oxycodone. In 2008, recreational use of oxycodone and hydrocodone was involved in 14,800 deaths. Some of the cases were due to overdoses of the acetaminophen component, resulting in fatal liver damage. In September 2013, the US Food and Drug Administration (FDA) released updated labeling guidelines for long-acting and extended-release opioids requiring manufacturers to remove moderate pain as an indication for use, instead stating the drug is for "pain severe enough to require daily, around-the-clock, long term opioid treatment". The updated labeling does not restrict physicians from prescribing opioids for moderate pain, as needed. Reformulated OxyContin is causing some recreational users to change to heroin, which is cheaper and easier to obtain.
Sources: en.wikipedia.org
=== Pharmacokinetics === Flurpiridaz (18F) has peak blood radioactivity at 2.3 minutes after administration, followed by a rise and plateau. Distribution of this radiopharmaceutical is complex, as it transfuses into the liver (13%), kidneys (9%), brain (8%) and epicardium (3%, radioactivity retains for 1 hour after administration). Full clearance is achieved within 48 hours. Only metabolites of flurpiridaz are excreted, mainly in urine and feces. Flurpiridaz metabolises into many different polar metabolites. There are no differences in pharmacokinetics caused by age, sex, body mass index (BMI), diabetic status, Clid Pugh A hepatic impairment and renal impairment at eGFR≥19-89 mL/min.
=== Fictional characters === Television: Fat Albert, Eric Cartman, Peter Griffin, Homer Simpson Video games: Fat Princess, Rufus (Street Fighter) Other: Blob (Marvel Comics), Butterball Cenobite (comics & films)
=== Thermospray interface === The thermospray (TSP) interface was developed in 1980 by Marvin Vestal and co-workers at the University of Houston. It was commercialized by Vestec and several of the major mass spectrometer manufacturers. The interface resulted from a long-term research project intended to find a LC–MS interface capable of handling high flow rates (1 ml/min) and avoiding the flow split in DLI interfaces. The TSP interface was composed of a heated probe, a desolvation chamber, and an ion focusing skimmer. The LC effluent passed through the heated probe and emerged as a jet of vapor and small droplets flowing into the desolvation chamber at low pressure. Initially operated with a filament or discharge as the source of ions (thereby acting as a CI source for vapourized analyte), it was soon discovered that ions were also observed when the filament or discharge was off. This could be attributed to either direct emission of ions from the liquid droplets as they evaporated in a process related to electrospray ionization or ion evaporation, or to chemical ionization of vapourized analyte molecules from buffer ions (such as ammonium acetate). The fact that multiply-charged ions were observed from some larger analytes suggests that direct analyte ion emission was occurring under at least some conditions. The interface was able to handle up to 2 ml/min of eluate from the LC column and would efficiently introduce it into the MS vacuum system. TSP was also more suitable for LC–MS applications involving reversed phase liquid chromatography (RT-LC).
While most organisms utilize the ubiquitous NAD+-dependent 2-oxoglutarate dehydrogenase, some bacteria utilize a ferredoxin-dependent 2-oxoglutarate synthase (EC 1.2.7.3). Other organisms, including obligately autotrophic and methanotrophic bacteria and archaea, bypass succinyl-CoA entirely, and convert 2-oxoglutarate to succinate via succinate semialdehyde, using EC 4.1.1.71, 2-oxoglutarate decarboxylase, and EC 1.2.1.79, succinate-semialdehyde dehydrogenase.
==== 1956–60 ==== In 1956, Sports Illustrated wrote that Mizell's return would help with St. Louis's pitching, a "major problem" for the Cardinals in 1955. His first outing back on April 17 was triumphant, as he allowed 12 hits but just two runs and came within one out of a complete game in a 4–2 victory over the Cincinnati Redlegs. From May 21 through June 9, he won five straight games, though he followed that up with three straight losses from June 15 through June 26. During the winning streak, in the second game of a May 27 doubleheader, he struck out 10 hitters in a 12–2 victory over the Chicago Cubs. In the first game of a doubleheader against Pittsburgh on August 23, he threw a four-hit shutout in a 3–0 victory. On September 7, 1956, facing the Redlegs, who were second to the Braves in a close pennant race, Mizell threw a two-hit shutout in a 1–0 victory. Six days later, he threw his second consecutive shutout, beating the Giants 5–0 and allowing just four hits. He had a 3.62 ERA for the Cardinals in 1956, and his 14–14 mark was reflective of St. Louis's .500 record. Mizell's 14 wins tied with Ron Kline and Hersh Freeman for 10th in the NL, but his 14 losses tied with Sam Jones, Al Worthington, and teammate Tom Poholsky for sixth. He ranked fifth in the NL with 153 strikeouts, and his mark of 6.6 strikeouts per nine innings pitched was good for third behind Jones's 8.4 and Harvey Haddix's 6.6. However, his 92 walks were third in the NL, behind Jones's 115 and Bob Buhl's 105.
Sources: en.wikipedia.org
Nausea: ~ 8%; 1% severe nausea and 1% discontinued treatment due to nausea. Diarrhea: ~ 7%; <1% of patients had severe diarrhea and <1% of patients discontinued treatment due to diarrhea. Less common adverse reactions: <1% A 2018 pooled analysis from three phase III, randomized, double-blind, placebo-controlled studies on usage for Opioid-Induced Constipation, found that the numbers of patients reporting adverse effects were similar in both the lubiprostone and placebo treatment groups for all opioid classes (P ≥ 0.125); however, gastrointestinal adverse effects were reported more frequently by those receiving lubiprostone than 2 of the 3 opioid groups. The most commonly reported TEAEs in the lubiprostone treatment groups were nausea (13.4%–18.1%), diarrhea (1.2%–13.9%), and abdominal pain (4.7%–5.6%). In the population overall, the greatest likelihood of experiencing the first episode of any of these three TEAEs was greatest in the first week of treatment and decreased thereafter. According to Medscape, the most common (>10%) were: Nausea, Diarrhea (7-12%), Headache (2-11%). Less common side effects (1-10%) included: Abdominal pain (4-8%), Abdominal distension (3-6%), Flatulence (4-6%), Vomiting (3%), Loose stools (3%), Edema (1-3%), Abdominal discomfort (1-3%), Dizziness (3%), Chest discomfort/pain (2%), Dyspnea (2%), Dyspepsia (2%), Fatigue (2%), Dry mouth (1%).
Some sources say that the El Niños of 2006-07 and 2014-16 were also Central Pacific El Niños. Recent years when La Niña Modoki events occurred include 1973–1974, 1975–1976, 1983–1984, 1988–1989, 1998–1999, 2000–2001, 2008–2009, 2010–2011, and 2016–2017. The recent discovery of ENSO Modoki has some scientists believing it to be linked to global warming. However, comprehensive satellite data go back only to 1979. More research must be done to find the correlation and study past El Niño episodes. More generally, there is no scientific consensus on how/if climate change might affect ENSO. There is also a scientific debate on the very existence of this "new" ENSO. A number of studies dispute the reality of this statistical distinction or its increasing occurrence, or both, either arguing the reliable record is too short to detect such a distinction, finding no distinction or trend using other statistical approaches, or that other types should be distinguished, such as standard and extreme ENSO. Likewise, following the asymmetric nature of the warm and cold phases of ENSO, some studies could not identify similar variations for La Niña, both in observations and in the climate models, but some sources could identify variations on La Niña with cooler waters on central Pacific and average or warmer water temperatures on both eastern and western Pacific, also showing eastern Pacific Ocean currents going to the opposite direction compared to the currents in traditional La Niñas.
210Po is extremely toxic; it and other polonium isotopes are some of the most radiotoxic substances to humans. With one microgram of 210Po being more than enough to kill the average adult, it is 250,000 times more toxic than hydrogen cyanide by weight. This is a consequence of its ionizing alpha radiation, as alpha particles are especially damaging to organic tissues inside the body. However, 210Po does not pose a radiation hazard when kept outside the body. The alpha particles it produces cannot penetrate the outer layer of dead skin cells. The toxicity of 210Po stems entirely from its radioactivity. It is not chemically toxic in itself, but its solubility in aqueous solution as well as that of its salts poses a hazard because its spread throughout the body is facilitated in solution. Intake of 210Po occurs primarily through contaminated air, food, or water, as well as through open wounds. Once inside the body, 210Po concentrates in soft tissues (especially in the reticuloendothelial system) and the bloodstream. Its biological half-life is approximately 50 days. In the environment, 210Po can accumulate in seafood. It has been detected in various organisms in the Baltic Sea, where it can propagate in, and thus contaminate, the food chain. 210Po is also known to contaminate vegetation, primarily originating from the decay of atmospheric radon-222 and absorption from soil. In particular, 210Po attaches to, and concentrates in, tobacco leaves.
Dipeptidyl peptidase-4 inhibitors inhibit dipeptidyl peptidase-4 and thus reduce glucagon and blood glucose levels. DPP-4 inhibitors combined with metformin include a sitagliptin/metformin combination (Janumet), a saxagliptin/metformin combination (Kombiglyze XR, Komboglyze), and an alogliptin/metformin combination (Kazano, Vipdomet). Linagliptin combined with metformin hydrochloride is sold under the brand name Jentadueto. As of August 2021, linagliptin/metformin is available as a generic medicine in the US.
The Chinese People's Armed Police Coast Guard Bureau, also abbreviated as China Coast Guard is the agency for maritime search and rescue and law enforcement in the territorial waters of the People's Republic of China. The China Coast Guard was formerly the maritime branch of the People's Armed Police (PAP) Border Security Force under the Ministry of Public Security until 2013. In March 2013, China announced it would form a unified Coast Guard commanded by the State Oceanic Administration. This renewed Coast Guard has been in operation since July 2013. As of 1 July 2018, the China Coast Guard was transferred from civilian control of the State Council and the State Oceanic Administration, to the People's Armed Police, ultimately placing it under the command of the Central Military Commission (CMC). According to Joel Wuthnow of the Institute for National Strategic Studies, the Coast Guard Command within the People's Armed Police possibly is of Corps Leader Grade, led by a Commandant who usually holds the rank of major general. In June 2018, China Coast Guard was granted maritime rights and law enforcement akin civilian law enforcement agencies in order to carry out contrast of illegal activities, keep peace and order, as well as safeguarding security at sea, when performing duties related to the use of marine resources, protection of marine environment, regulation of fishery, and anti-smuggling. There are currently 3 regional bureaus:
Sources: en.wikipedia.org
The lyophilised solid is best kept cold, dry and dark, typically at minus twenty degrees Celsius. Moisture and repeated warming cycles are the main causes of degradation. Solutions prepared from the powder are less stable and are normally used quickly.
Reversed-phase liquid chromatography assesses purity, while mass spectrometry confirms molecular mass and detects sequence errors. Amino acid analysis and peptide mapping add structural detail. These techniques are complementary rather than interchangeable.
It is listed as a prohibited peptide hormone by the World Anti-Doping Agency. No medicines regulator has approved it for human use. Import and sale rules vary by country.
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.