melanotan-2 comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-05-11. Where a claim depends on a specific study, the study is described rather than over-claimed.
Melanocortin receptors comprise five subtypes with distinct tissue distributions and functions. Melanotan-2 is described in the literature as a non-selective agonist that engages several of these subtypes, including MC1R, MC3R, MC4R, and MC5R. MC1R is the subtype most directly linked to melanin production in skin cells. Because the compound is not subtype-selective, its observed effects in experimental settings are generally attributed to activity across multiple receptor pathways rather than to a single target.
Melanotan-2 is a synthetic linear peptide built from seven amino acids arranged in a short chain. Its sequence is commonly written as Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH2, which includes a modified N-terminus and an amidated C-terminus. The molecule belongs to the melanocortin family and acts as a receptor agonist. Structural features such as the D-phenylalanine residue and the Nle substitution are associated with increased stability against enzymatic degradation relative to the natural parent peptide.
The peer-reviewed record is dominated by small early-phase studies, case reports and pharmacovigilance summaries rather than large randomised trials. Papers typically examine tanning response, receptor selectivity or patterns of reported adverse events. Many note that participants obtained the peptide outside a clinical setting, which limits verification of composition and administered amount. Reported events vary widely, and causality is frequently unclear because the identity and purity of self-sourced material are unknown. Open questions include whether repeated melanocortin receptor stimulation produces cumulative effects, and how often label claims match actual content.
Identification in laboratories relies on reversed-phase liquid chromatography coupled with tandem mass spectrometry, with product-ion spectra compared against a certified reference standard. High-resolution mass spectrometry supplies accurate mass confirmation, and peptide mapping after enzymatic digestion separates melanotan II from closely related analogues. Quantitation of seized material is complicated by unknown counter-ions and residual trifluoroacetate left from purification. Immunoassays raised against alpha-melanocyte-stimulating hormone can cross-react, so chromatographic confirmation is normally required. Urinary detection windows are short, and reported limits of detection differ substantially between laboratories.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Free base; salt forms differ |
| Molecular weight | Approximately 1024 g/mol | Calculated for the free base |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water and polar solvents | Poorly soluble in non-polar solvents |
| Typical storage | -20 degrees Celsius, dry, protected from light | Refers to the solid form |
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.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Retention time supports identity, while the mass spectrum confirms the molecular weight of the intact peptide. Purity is frequently reported as a percentage of total peak area, a figure that depends on the wavelength, column and gradient used. Impurity profiling may also look for truncated sequences, oxidised forms and residual counterions. Amino acid analysis and peptide mapping provide orthogonal confirmation when required.
Regulatory status varies by jurisdiction, and the substance is frequently described as unapproved for therapeutic use. Some authorities classify it alongside prescription-only medicines or controlled categories, while others address it through general consumer protection rules. Analytical surveys have reported mismatches between label claims and measured content in products sold online, although the scope of such testing is limited. Whether these discrepancies are widespread remains an open question. Discussion in the literature therefore tends to combine chemistry, supply-chain observation and policy analysis.
Outside regulated medicine, melanotan II circulates through online vendors as a research chemical, often marketed for tanning. Products sold this way vary widely in purity, concentration, and labeling accuracy, and independent testing has documented discrepancies. Published reports describe both pigment effects and adverse reactions, including nausea, flushing, and darkening of existing moles. Long-term safety data are sparse, and no large controlled trial has established a risk profile. Questions about cumulative effects on melanocytes remain unresolved in the literature.
Melanotan II is a synthetic peptide analog modeled on alpha-melanocyte-stimulating hormone, a naturally occurring signaling peptide involved in pigmentation. Its structure is a cyclic heptapeptide containing two non-natural substitutions, norleucine at position four and D-phenylalanine at position seven. These modifications resist enzymatic breakdown and extend the molecule's activity relative to the native hormone. The compound binds melanocortin receptors and is studied mainly as a pharmacological tool rather than a therapeutic product. It has never received approval as a medicine in any major jurisdiction.
Identity and purity are assessed with chromatographic and mass spectrometric techniques. Reversed-phase high-performance liquid chromatography separates the target peptide from related impurities and degradation products, and the resulting retention time is compared against a reference standard. Mass spectrometry, often coupled to liquid chromatography, confirms molecular mass. Amino acid analysis or peptide mapping can provide additional sequence-level confirmation when required. Results are only as reliable as the reference materials used alongside them.
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.
1934 The first widely known scientific publication on the impact of dietary restriction on life expectancy, authored by Clive McCay. McCay's group carried out intensive research in this direction in 1930–43, soon other scientists began to do related research. The effect of increasing life expectancy by starvation is usually observed in rats and mice, whose development until puberty is very labile (growth retardation and puberty, decreased metabolism and body temperature). In larger animals, such as rabbits, dogs and monkeys, the effect is less pronounced. The impact of fasting on human life expectancy still remains a question where not everything is clear and is unambiguous. 1936 The first European (and Western) journal about aging and longevity. It was published in Kishinev by Dimu Kotsovsky. During the first year of existence it was called Monatsberichte, then got the name German: Altersprobleme: Zeitschrift für Internationale Altersforschung und Altersbekämpfung = "Problems of Aging: Journal for the International Study and Combat of Aging". The journal published materials mostly in the German language, less in French and English. 1937 A Ukrainian Soviet pathophysiologist Alexander Bogomolets created antireticular cytotoxic serum in the hope to extend life of people to 150 years. Although the drug did not achieve its main goal, it has become widely used for the treatment of a number of diseases, especially infectious diseases and fractures. The serum of Bogomolets was actively used in Soviet hospitals during WWII.
===== Structure-activity relationship (SAR) ===== Important structure-activity relationship: 1. Strict steric constraint exists around the pyrrolidine ring of cyanopyrrolidine-based inhibitors, with only hydrogen, fluoro, acetylene, nitrile, or methano substitution permitted. 2. Presence of a nitrile moiety on the pyrrolidine ring is critical to achieving potent activity Also, systematic SAR investigation has shown that the ring size and stereochemistry for the P2 position is quite conditioned. A 5-membered ring and L-configuration has shown better results than a 4-membered or 6-membered ring with D-configuration. Only minor changes on the pyrrolidine ring can be tolerated, since the good fit of the ring with the hydrophobic S1 pocket is very important for high affinity. Some trials have been made, e.g. by replacing the pyrrolidine with a thiazoline. That led to improved potency but also loss of chemical stability. Efforts to improve chemical stability often led to loss of specificity because of interactions with DPP-8 and DPP-9. These interactions have been connected with increased toxicity and mortality in animals. There are strict limitations in the P1 position and hardly any changes are tolerated. On the other hand, a variety of changes can be made in the P2 position. In fact, substitution with quite big branched side chains, e.g. tert-butylglycin, normally increased activity and chemical stability, which could lead to longer-lasting inhibition of the DPP-4 enzyme. It has also been noted that biaryl-based side chains can also give highly active inhibitors.
Guinness ( ) is a stout that originated in the brewery of Arthur Guinness at St. James's Gate, Dublin, Ireland, in the 18th century. It is now owned by the British multinational alcoholic beverage maker Diageo. It is one of the most successful alcohol brands worldwide, brewed in almost 50 countries, and available in over 120. Sales in 2011 amounted to 850,000,000 litres (190,000,000 imp gal; 220,000,000 U.S. gal). It is the highest-selling beer in both Ireland and the United Kingdom. The Guinness Storehouse is a tourist attraction at St. James's Gate Brewery in Dublin, Ireland. Since opening in 2000, it has received over 20 million visitors. Adopted in 1862 by the incumbent proprietor, Benjamin Lee Guinness, the Guinness harp motif is modelled on the Trinity College harp (which is the national symbol of Ireland), with the right-facing harp registered as a trademark for Guinness in 1876. Guinness's flavour derives from malted barley and roasted unmalted barley. The unmalted barley is a relatively modern addition that became part of the grist in the mid-20th century. For many years, a portion of aged brew was blended with freshly brewed beer to give a sharp lactic acid flavour. Although Guinness's palate still features a characteristic "tang", the company has refused to confirm whether this type of blending still occurs. The draught beer's thick and creamy head comes from mixing the beer with nitrogen and carbon dioxide. Guinness moved its headquarters to London at the beginning of the Anglo-Irish trade war in 1932.
The 2026 NCAA Division I men's basketball championship game is held at Lucas Oil Stadium in Indianapolis, in which the Michigan Wolverines beat the UConn Huskies 69–63 to win their second title and first since 1989. April 7 Iran war Trump warns that "a whole civilization will die tonight, never to be brought back again" unless Iran reaches a deal on reopening the Strait of Hormuz, and sets a deadline of 20:00 EDT. Following Trump's threat to "end its civilization", Democrats and former Republican congresswoman Marjorie Taylor Greene call for the invocation of the 25th amendment of the United States Constitution. Additionally, Democrats call for Trump to be impeached. Trump announces a two-week ceasefire that was mediated via Pakistan. He agrees to "suspend the bombing and attacks on Iran for a period of two weeks", subject to Iran agreeing to the "complete, immediate and safe opening" of the Strait of Hormuz, and to allow time for an agreement to be reached. Assistant District Attorney Clay Fuller, a Trump-endorsed Republican, wins the special election in Georgia to replace Marjorie Taylor Greene, who resigned in January following a public fallout with Trump. Judge Chris Taylor, the Democratic-backed candidate, wins election to the Wisconsin Supreme Court. The result expands the court's liberal majority to 5–2. AI firm Anthropic announces a new model for its Claude language model, named Mythos, designed for locating cybersecurity vulnerabilities and debugging. April 8 Trump threatens 50% tariffs on countries who distribute weapons to Iran.
Sources: en.wikipedia.org
Methods have been developed to purify DNA from organisms, such as phenol-chloroform extraction, and to manipulate it in the laboratory, such as restriction digests and the polymerase chain reaction. Modern biology and biochemistry make intensive use of these techniques in recombinant DNA technology. Recombinant DNA is a man-made DNA sequence that has been assembled from other DNA sequences. They can be transformed into organisms in the form of plasmids or in the appropriate format, by using a viral vector. The genetically modified organisms produced can be used to produce products such as recombinant proteins, used in medical research, or be grown in agriculture.
Direct-to-consumer blood testing (DTC blood testing), also known as direct access testing (DAT), is a form of laboratory testing that allows consumers to order blood tests directly from a clinical laboratory without requiring a prescription or referral from a physician. This market has grown significantly in recent years, driven by consumer interest in personalized health management, advances in laboratory technology, and regulatory changes that have expanded access in many jurisdictions. These services typically offer comprehensive metabolic panels, lipid profiles, hormone testing, nutritional markers, and increasingly sophisticated biomarker assessments that were traditionally only available through healthcare providers. Over the last decade, a paradigm shift has taken place with consumers seeking greater involvement in decisions affecting their healthcare and with policies that enable this involvement.
Actinium is a chemical element; it has symbol Ac and atomic number 89. It was discovered by Friedrich Oskar Giesel in 1902, who gave it the name emanium; the element got its name by being wrongly identified with a substance André-Louis Debierne found in 1899 and called actinium. The actinide series, a set of 15 elements between actinium and lawrencium in the periodic table, is named after actinium. Together with polonium, radium, and radon, actinium was one of the first non-primordial radioactive elements to be discovered. A soft, silvery-white radioactive metal, actinium reacts rapidly with oxygen and moisture in air, forming a white coating of actinium oxide that prevents further oxidation. As with most lanthanides and many actinides, actinium assumes oxidation state +3 in nearly all its chemical compounds. Actinium is found only in traces in uranium and thorium ores as the isotope 227Ac, which decays with a half-life of 21.772 years, predominantly emitting beta and sometimes alpha particles, and 228Ac, which is beta active with a half-life of 6.15 hours. One tonne of natural uranium in ore contains about 0.2 milligrams of actinium-227, and one tonne of thorium contains about 5 nanograms of actinium-228. The close similarity of physical and chemical properties of actinium and lanthanum makes the separation of actinium from the ore impractical. Instead, the element is prepared, in milligram amounts, by the neutron irradiation of 226Ra in a nuclear reactor. Owing to its scarcity, high price, and radioactivity, actinium has no significant industrial use.
=== Synthesis === Trimebutine can be synthesised from 1-phenylpropan-1-one (1). Firstly, it is converted to the corresponding oxirane through trimethylsulfoxonium idoide with sodium hydride in DMSO and THF, yielding 2-ethyl-2-phenyl-oxirane (2). Next, 2 undergoes ring-opening with dimethylaluminium N,N-dimethylamide in diethyl ether, yielding 2-(dimethylamino)-2-phenyl-butan-1-ol (4) and 2-phenylbutanal (3) as a byproduct. Then, 4 reacts with 3,4,5-trimethoxybenzoyl chloride (5) in triethylamine and THF, which is catalysed by 4-dimethylaminopyrridine (DMAP), yielding trimebutine.
The area returned to the English crown in 1157, when Henry II of England took possession of the area (from Malcolm IV of Scotland). Henry II formed two new counties from the former earldom: Westmorland and Carliol – originally an abbreviation of the Latin Carlioliensis '[bishop] of Carlisle'. Westmorland also included areas formerly part of the Earldom of Lancaster. The lead- and silver-mining area of Alston, previously associated with the Liberty of Tynedale was later also added to the new county of Carliol for financial reasons. By 1177, Carliol had become known as Cumberland. The border between England and Scotland was made permanent by the Treaty of York in 1237. The population of Cumberland in the 1841 census was 178,038.
Sources: en.wikipedia.org
No. Melanotan-2 is manufactured synthetically. The naturally occurring peptide in the same family is alpha-melanocyte-stimulating hormone, which the body produces as part of normal endocrine and neural signalling.
Both are synthetic analogues derived from the same parent hormone. Reference descriptions usually characterise afamelanotide as more selective for the MC1R subtype, whereas melanotan-2 is reported to interact with a wider range of melanocortin receptors.
Early studies explored melanocortin signalling and pigmentation, which later led to informal use of the label tanning peptide. That label is not a regulatory category and does not imply approved status for any purpose.
Regulatory treatment varies by country. In the United States, the European Union and Australia it is an unapproved drug and its sale is restricted, while some other jurisdictions list it as prescription-only or controlled. The applicable rules depend on the country of import.