Everything below concerns alpha-MSH analogue. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-11-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 compound emerged from research programs in the 1980s that examined analogues of alpha-melanocyte-stimulating hormone for pigmentation and photoprotection. Investigators modified the native sequence to extend activity duration and potency. A related analogue, afamelanotide, was developed within the same broad line of inquiry and eventually gained approval in certain jurisdictions for a rare light-sensitivity condition. Melanotan-2 itself did not progress through the same regulatory route and has no approved therapeutic indication.
| Property | Value | Notes |
|---|---|---|
| Lyophilised storage | −20 °C, dry, protected from light | Vials are sealed and allowed to reach room temperature before opening |
| Reconstituted storage | 2 to 8 °C, protected from light | Short-term holding; avoid repeated freeze-thaw cycles |
| Reconstitution solvent | Water for injection or bacteriostatic water | Added slowly along the vial wall to reduce foaming and shear |
| Purity measurement | RP-HPLC with area normalisation | Acetonitrile-water gradient monitored at roughly 214 nm |
| Identity confirmation | Electrospray ionisation mass spectrometry | Observed mass compared against the calculated peptide mass |
Regulatory status differs by country, and in many places supplying the compound for human consumption is unlawful. Vendors frequently label material as intended for research use only, a designation that shifts stated purpose but does not create a legal pathway for personal use. Certificates of analysis accompanying such products vary widely in detail and provenance. Third-party testing exists but is voluntary, and results are rarely linked to a specific lot in a publicly verifiable way.
Identity testing for a synthetic peptide relies on several complementary methods. Reversed-phase high-performance liquid chromatography separates the target from related impurities and reports purity as a percentage of total peak area. Mass spectrometry confirms molecular mass and can reveal deletions or truncations. Amino acid analysis and peptide mapping provide sequence-level confirmation, while counter-ion content and residual solvents are measured separately. A purity figure alone does not establish identity, so a complete dataset combines chromatographic and spectrometric evidence.
Lyophilized peptide powder is generally stored frozen, protected from light and moisture. Tryptophan residues are susceptible to oxidation, and the lactam bridge can hydrolyze under strongly acidic or basic conditions. Solutions prepared for laboratory work degrade faster than dry powder, and repeated freeze-thaw cycles accelerate loss. Common practice is to aliquot solutions before freezing and to avoid alkaline buffers. Reported stability windows vary with concentration, buffer, and temperature, so exact shelf lives are method-specific rather than universal.
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.
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.
Melanotan-2 is handled in the laboratory as a lyophilised powder that dissolves readily in water, dimethyl sulfoxide and dimethylformamide, with limited solubility in ethanol. Stock solutions prepared in an organic solvent often precipitate when diluted into aqueous buffer, so gradual dilution with mixing is standard practice. The peptide carries a tryptophan residue and a histidine residue, both sensitive to oxidation and to alkaline conditions. Working solutions are therefore kept near neutral to slightly acidic pH, protected from light, and consumed within the same working session whenever that is practical.
Solid peptide kept dry at minus twenty degrees Celsius, shielded from light and moisture, is generally considered stable for extended periods. Solutions are divided into single-use aliquots and held at minus twenty or minus eighty degrees Celsius, because repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. Hydrolysis of the backbone and oxidation of tryptophan are the principal degradation routes in aqueous solution, and both accelerate at ambient temperature. Hygroscopic uptake after a vial is opened can also shift the actual mass weighed, which affects any concentration calculated from it.
The compound was developed in the late 1980s and 1990s by academic researchers investigating photoprotection. The rationale held that stimulating melanin production might reduce ultraviolet damage to skin and lower skin cancer risk. Early work examined receptor binding, pigment response, and short-term tolerability in small studies. That program did not produce an approved drug, and formal development stalled after early-phase trials. Whether induced pigmentation confers meaningful photoprotection remains an open question.
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.
== Membrane separation processes == Membrane separation processes have a very important role in the separation industry. Nevertheless, they were not considered technically important until the mid-1970s. Membrane separation processes differ based on separation mechanisms and size of the separated particles. The widely used membrane processes include microfiltration, ultrafiltration, nanofiltration, reverse osmosis, electrolysis, dialysis, electrodialysis, gas separation, vapor permeation, pervaporation, membrane distillation, and membrane contactors. All processes except for pervaporation involve no phase change. All processes except electrodialysis are pressure driven. Microfiltration and ultrafiltration is widely used in food and beverage processing (beer microfiltration, apple juice ultrafiltration), biotechnological applications and pharmaceutical industry (antibiotic production, protein purification), water purification and wastewater treatment, the microelectronics industry, and others. Nanofiltration and reverse osmosis membranes are mainly used for water purification purposes. Dense membranes are utilized for gas separations (removal of CO2 from natural gas, separating N2 from air, organic vapor removal from air or a nitrogen stream) and sometimes in membrane distillation. The later process helps in the separation of azeotropic compositions reducing the costs of distillation processes.
She trained at the London Academy of Music and Dramatic Art and her stage work has included appearances with the National Theatre and the Royal Shakespeare Company. She was made a dame in the 2020 Queen's Birthday Honours for services to charity, entertainment and the arts. David Littman (activist) (4 July 1933 – 20 May 2012) author of over five books and scores of monographs and academic papers and activist best known for organising the departure of Jewish children from Morocco; then worked as lobbyist at the United Nations in Geneva and was also historian. He was married to Bat Ye'or. Emanuel Litvinoff, novelist. (5 May 1915 – 24 September 2011) was a British writer and well-known figure in Anglo-Jewish literature, known for novels, short stories, poetry, plays and human rights campaigning. Litvinoff became aware of plight of persecuted Soviet Jews, and started worldwide campaign against this persecution. Due to Litvinoff's efforts, prominent Jewish groups in United States became aware of issue, and well-being of Soviet Jews became cause for a worldwide campaign, eventually leading to mass migration of Jews from the Soviet Union to Israel and the United States. For this he has been described by Meir Rosenne, former Israeli ambassador to the United States, as "one of the greatest unsung heroes of the twentieth century... who won in the fight against an evil empire" and that "thousands and thousands of Russian Jews owe him their freedom".
Liver Function Tests at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Liver Function Tests at Lab Tests Online Overview at Mayo Clinic Abnormal Liver Function Tests Archived 11 April 2012 at the Wayback Machine Overview of liver enzymes Abnormal Liver Tests Curriculum at AASLD Further workup of abnormal liver tests: "etiology panel"
Based on a 2002 crystal structure analysis, α-amanitin interacts with the bridge helix in RNA polymerase II (pol II). This interaction interferes with the translocation of RNA and DNA needed to empty the site for the next round of RNA synthesis. The addition of α-amanitin can reduce the rate of pol II translocating on DNA from several thousand to a few nucleotides per minute, but has little effect on the affinity of pol II for nucleoside triphosphate, and a phosphodiester bond can still be formed. The bridge helix has evolved to be flexible and its movement is required for translocation of the polymerase along the DNA backbone. Binding of α-amanitin puts a constraint on its mobility, hence slowing down the translocation of the polymerase and the rate of synthesis of the RNA molecule.
=== Lipids === An indication of the role of high-density lipoprotein (HDL) on atherosclerosis has been with the rare Apo-A1 Milano human genetic variant of this HDL protein. A small short-term trial using bacterial-synthesized human Apo-A1 Milano HDL in people with unstable angina produced a fairly dramatic reduction in measured coronary plaque volume in only six weeks vs. the usual increase in plaque volume in those randomized to placebo. The trial was published in JAMA in early 2006. Ongoing work starting in the 1990s may lead to human clinical trials—probably by about 2008. These may use synthesized Apo-A1 Milano HDL directly, or they may use gene-transfer methods to pass the ability to synthesize the Apo-A1 Milano HDLipoprotein. Methods to increase HDL particle concentrations, which in some animal studies largely reverse and remove atheromas, are being developed and researched. However, increasing HDL by any means is not necessarily helpful. For example, the drug torcetrapib is the most effective agent currently known for raising HDL (by up to 60%). However, in clinical trials, it also raised deaths by 60%. All studies regarding this drug were halted in December 2006. The actions of macrophages drive atherosclerotic plaque progression. Immunomodulation of atherosclerosis is the term for techniques that modulate immune system function to suppress this macrophage action.
Sources: en.wikipedia.org
== Technological achievements == In addition to being credited with the development of one of the first anti-virus programs, "Vaccine", Tippett pioneered and commercialized a string of now-common technologies including what is now called the "Recovery Disk," processor image signatures, using hash-tables for trusted file execution and anomaly detection, aspects of mail merge and "un-do." He ran a bulletin board system for CP/M software before the first IBM PC was created and was president of the Cleveland Osborne Group (a user group for the computers of the Osborne Computer Corporation) in the early 1980s. As chief scientist for ICSA.net, Tippett was one of a handful of experts to identify and address the ILOVEYOU virus that broke in May 2000 and provided key information to the Department of Justice about David Smith, the writer of the Melissa virus. He was featured on the cover of the August 2000 issue of Time Digital magazine.
== History == The importance of TNF in the development of rheumatoid arthritis was originally demonstrated by George Kollias and colleagues in proof of principle studies in transgenic animal models. Infliximab was developed by Junming Le (b. 1940) and Jan Vilček (b. 1933) at New York University School of Medicine and in collaboration with Centocor (now Janssen Biotech, Inc.).
Glutaminase kidney isoform (sometimes ambiguously just called glutaminase) is an enzyme that in humans is encoded by the GLS gene. This protein is a type of glutaminase found in the mitochondria of kidney and brain cells. It is involved in both breaking down the amino acid glutamine in the kidneys, and regulating the levels of glutamate (a neurotransmitter and amino acid) in the brain.
== "The First Lady of Chromatography" == After graduating, Smolková-Keulemansová joined the Faculty of Sciences at Charles University and focused on analytical chemistry. In the early 1950s, she built a team focused on modern analytical separation methods such as gas chromatography, high-performance liquid chromatography and electromigration. At the same time, she attended an analytical conference in Prague, leading to her finding a volumetric chromatographic device. Her team began to prepare its own device with volumetric detection and constructed a more universal glass thermal conductivity detector, allowing them to analyze a larger variety of gases. Later, this novel detector became part of a commercially available instrument. Because of her innovation and dedication to the field, she began to be referred to as "the first lady of chromatography".
The term "Quechua Nation" occurs in such contexts as the name of the Education Council of the Quechua Nation (Consejo Educativo de la Nación Quechua, CENAQ), which is responsible for Quechua instruction or bilingual intercultural schools in the Quechua-speaking regions of Bolivia. Some Quechua say that if nation-states in Latin America had been built following the European pattern, they would be a single, independent nation.
Sources: en.wikipedia.org
Low temperature slows hydrolysis and oxidation, the two main routes by which the peptide backbone and side chains are modified. A lyophilised powder stored at −20 °C is more stable than one kept at room temperature, and once the material is dissolved the degradation rate rises, making refrigeration more important.
Liquid chromatography coupled to mass spectrometry is the most common approach because it combines a retention time with a mass measurement. A chromatographic peak alone cannot establish which peptide is present, so mass determination or amino acid analysis is used as an orthogonal confirmation alongside the separation.
This depends on buffer, pH, and concentration, and published stability data for this peptide are limited. In practice laboratories work through a refrigerated solution within a few weeks and discard samples that show cloudiness or visible particles. Freezing and thawing repeatedly is generally discouraged.
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.