If you have been reading about prohibited list and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-02-26. Numbers and descriptions here follow the published literature rather than marketing 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.
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 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.
| 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 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.
Reversed-phase high-performance liquid chromatography is the routine method for purity assessment. Peptides absorb near 214 nm because of the peptide bond, and a gradient of acetonitrile in water separates the intact peptide from deletion sequences, oxidised products, and earlier-eluting fragments at neutral pH. Electrospray ionisation mass spectrometry provides an orthogonal check: the measured mass must agree with the theoretical value. Amino acid analysis and peptide mapping confirm structure but are used less often. Reference standards remain scarce because the peptide is not described in any pharmacopoeia.
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.
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.
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.
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.
=== Stroke prevention === Transcranial Doppler ultrasound (TCD) can detect children with sickle cell who have a high risk for stroke. The ultrasound test detects partially obstructed blood vessels by measuring blood flow into the brain, as blood flow velocity is inversely related to arterial diameter. Consequently, high blood flow velocity correlates with narrowed arteries. In children, preventive RBC transfusion therapy has been shown to reduce the risk of first stroke or silent stroke when transcranial Doppler ultrasonography shows abnormal cerebral blood flow. In those who have sustained a prior stroke event, it also reduces the risk of recurrent stroke and additional silent strokes.
Nonetheless, Neanderthal use of projectile weapons in hunting occurred very rarely (or perhaps never) and the Neanderthals hunted large game animals mostly by ambushing them and attacking them with handheld weapons such as thrusting spears rather than attacking them from a distance with projectiles.
== Engineering == In biochemical engineering, sparging can remove low-boiling liquids from a solution. The low-boiling components evaporate more rapidly, so the gas bubbles remove more of them from the bulk solution containing higher-boiling components. It is an alternative to distillation, and it does not require heat.
Druze constitute one third of the residents of Rachaya District, and more than a quarter of the residents of Chouf District, which is considered the heartland of the Lebanese Druze community, as well as in the Matn District. They also constitute a significant minority in Marjeyoun District. On the other hand, Christians constitute approximately 40% of the population in Chouf District, and about a quarter of the populations in Rashaya District, while comprising a majority in Matn District and Marjeyoun District. Baabda District and Hasbaya District are predominantly inhabited by Christians and Druze populations. In 2021 the largest Druze communities outside the Middle East are in Venezuela (60,000) and in the United States (50,000); both are predominantly Christian countries. Members of the Druze faith in the United States encounter challenges such as finding a Druze partner and adhering to endogamy, as marriage outside the Druze faith is strongly discouraged according to Druze doctrine. Additionally, they face the task of preserving their religious traditions, because many Druze immigrants to the United States have converted to Protestantism, joining primarily the Presbyterian or Methodist churches. The early Druze migrants to Venezuela integrated well with the local population, and some Druze converted to Catholicism. However, the majority maintained a strong sense of Druze and Arab identity and adhered to Druze values. A notable example of Druze influence in this predominantly Catholic country is the former vice president, Tareck El Aissami, who is of Druze descent.
The cell membrane, or plasma membrane, is a selectively permeable membrane as an outer boundary of the cell that encloses the cytoplasm. Underlying, and attached to the cell membrane is the cell cortex, the outermost part of the actin cytoskeleton. The membrane serves to separate and protect a cell from its surrounding environment and is made mostly from a lipid bilayer of phospholipids, which are amphiphilic (partly hydrophobic and partly hydrophilic). It has been best described in the fluid mosaic model. Embedded within the cell membrane are secretory macromolecular lipoprotein structures called porosomes; and a number of different channels and pumps involved in actively transporting molecules into and out of the cell. The membrane is semi-permeable, and selectively permeable, in that it can either let a substance (molecule or ion) pass through freely, to a limited extent or not at all. Cell surface receptors in the membrane allow cells to detect external signaling molecules such as hormones.
Sources: en.wikipedia.org
== Active site == The active site of the second structure has 2 tunnels, one with a radius of 1.21 Å and one with a radius of 1.19 Å. The 1.21 Å tunnel has a length of 26.7 Å and the 1.19 Å tunnel has a length of 27.5 Å. The active site of the first version has one tunnel that has a radius of 1.14 Å and a length of 26.0 Å. As with the structures, these parts of the enzyme can be examined further using the links in the caption.
It was fought to preserve Poland's independence and the nobility's traditional interests. After several years, it was brought under control by forces loyal to the king and those of the Russian Empire. Following the suppression of the Bar Confederation, parts of the Commonwealth were divided up among Prussia, Austria and Russia in 1772 at the instigation of Frederick the Great of Prussia, an action that became known as the First Partition of Poland: the outer provinces of the Commonwealth were seized by agreement among the country's three powerful neighbors and only a rump state remained. In 1773, the "Partition Sejm" ratified the partition under duress as a fait accompli. However, it also established the Commission of National Education, a pioneering in Europe education authority often called the world's first ministry of education.
== Menu and themes == Zaxbys is a fast casual restaurant offering Chicken Fingerz, chicken wings, fried shrimp, sandwiches, and salads. Dipping sauces are offered with chicken finger orders, and range from mild, to the moderate "Zax Sauce", to the intensely hot "Nuclear". Dining rooms at Zaxbys restaurants are decorated with assorted whimsical objects and signs, which often vary in theme by location and region. Some locations in college towns feature objects and decorations related to the local university. Similarly, citrus-industry themed decorations line the walls at a location in Orlando, Florida.
==== List of regions ==== Sometimes, overlaps and transition areas happen between the various regions of Lower Saxony. Several of the regions listed here are part of other, larger regions, that are also included in the list.
The Rumack–Matthew nomogram, also known as the acetaminophen nomogram, is an acetaminophen toxicity nomogram. It plots serum concentration of acetaminophen against the time since ingestion, in order to predict possible liver toxicity and allow a clinician to decide whether to proceed with N-Acetylcysteine (NAC) treatment. It is a logarithmic graph starting 4 hours after ingestion; at this time the absorption of acetaminophen is considered likely to be complete. This nomogram allows for timely management of an acetaminophen overdose. Generally, a serum plasma concentration (APAP) of 140–150 μg/mL (or mg/L) at 4 hours post-ingestion indicates the need for NAC treatment. This nomogram is not used alone if the patient has altered mental status or if the history is not reliable; rather, an additional line should be drawn and plotted to see if the slope of the line remains at or above the nomogram. Additionally, a formal half-life may also be determined, by measuring concentration first upon admission of the patient and again 4 hours later; from these measurements, half-life can be calculated. If half-life is more than 4 hours, then treatment is necessary to prevent hepatotoxicity and liver failure. The original line, sometimes referred to as the Rumack–Matthew line, starts at 200 μg/mL at 4 hours and was published in 1975 by Barry H. Rumack and Henry Matthew. When the NAC study began in 1976, the U.S. Food and Drug Administration (FDA) required a line that was 25% below the original. This line is referred to as the treatment line and starts at 150 μg/mL at 4 hours.
Sources: en.wikipedia.org
Receptor tyrosine kinase, as in fibroblast growth factor receptor. Most enzyme-linked receptors are of this type. Receptor protein serine/threonine kinase, as in bone morphogenetic protein Guanylate cyclase, as in atrial natriuretic factor receptor
Adrien-Marie Legendre (; French: [adʁiɛ̃ maʁi ləʒɑ̃dʁ]; 18 September 1752 – 9 January 1833) was a French mathematician who made numerous contributions to mathematics. Well-known and important concepts such as the Legendre polynomials and Legendre transformation are named after him. He is also known for his contributions to the method of least squares, and was the first to officially publish on it, though Carl Friedrich Gauss had discovered it before him.
The galanin receptor is a G protein-coupled receptor, or metabotropic receptor which binds galanin. Galanin receptors can be found throughout the peripheral and central nervous systems and the endocrine system. So far three subtypes are known to exist: GAL-R1, GAL-R2, and GAL-R3. The specific function of each subtype remains to be fully elucidated, although as of 2009 great progress is currently being made in this respect with the generation of receptor subtype-specific knockout mice, and the first selective ligands for galanin receptor subtypes. Selective galanin agonists are anticonvulsant, while antagonists produce antidepressant and anxiolytic effects in animals, so either agonist or antagonist ligands for the galanin receptors may be potentially therapeutic compounds in humans.
==== Knight Commander of the Order of the British Empire (KBE) ==== Military Division Vice Admiral Michael Antony Claes Moore, . Civil Division The Right Honourable Baron Thomas Alexander Fermor Hesketh. For political service.
=== Pregnancy and breastfeeding === Spironolactone can cross the placenta. It has been found in the breast milk of lactating mothers, but only very small amounts of spironolactone and its metabolite canrenone enter breast milk, and the amount received by an infant during breastfeeding (<0.5% of the mother's dose) is considered to be insignificant. A study found that spironolactone was not associated with teratogenicity in the offspring of rats. Because it is an antiandrogen, however, spironolactone could theoretically have the potential to cause feminization of male fetuses at sufficient doses. In accordance, a subsequent study found that partial feminization of the genitalia occurred in the male offspring of rats that received doses of spironolactone that were five times higher than those normally used in humans (200 mg/kg per day). Another study found permanent, dose-related reproductive tract abnormalities rat offspring of both sexes at lower doses (50 to 100 mg/kg per day). In practice however, although experience is limited, spironolactone has never been reported to cause observable feminization or any other congenital defects in humans. Among 31 human newborns exposed to spironolactone in the first trimester, no signs of any specific birth defects were seen. A case report described a woman who was prescribed spironolactone during pregnancy with triplets and delivered all three (one boy and two girls) healthy; no observable feminization occurred in the boy.
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.
No. It is a synthetic analogue carrying four amino acid changes, a lactam ring and an amidated C-terminus. The natural hormone is a linear thirteen-amino-acid peptide processed from proopiomelanocortin.