melanocortin receptor raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
Reviewed 2026-05-14. Anything still debated is marked as such rather than presented as settled.
Melanotan-2 is a synthetic peptide designed as an analog of alpha-melanocyte-stimulating hormone, a signaling molecule produced in the pituitary and skin. Its structure is a linear chain of seven amino acids that folds into a ring through an internal lactam bridge joining two side chains. The compound is sometimes written as MT-II or MEL-2 in informal and commercial contexts. It belongs to the melanocortin peptide family, a group of short signaling molecules that share a conserved core sequence recognized by melanocortin receptors.
Two structural changes distinguish the synthetic peptide from the natural hormone. A norleucine residue replaces methionine at one position, and a D-configured phenylalanine replaces the natural L-form at another. Both substitutions slow enzymatic breakdown, which extends the molecule's persistence relative to the parent hormone. The lactam bridge further constrains the backbone into a stable conformation. These features are standard design strategies in peptide chemistry and are not unique to this compound; they appear across many research peptides built for improved stability.
Activity is attributed to agonism at melanocortin receptors, particularly MC1R and MC4R. Activation of MC1R on melanocytes increases melanin synthesis, which underlies the reported tanning effect. MC4R engagement in the central nervous system is linked to appetite suppression and to effects on sexual arousal reported in early clinical studies. Those studies were small and were not designed to establish efficacy or long-term safety. Receptor selectivity among the melanocortin subtypes is not absolute, which complicates attribution of any effect to a single pathway.
Regulatory treatment varies between countries. Several national medicines agencies have classified the peptide as unapproved, and customs authorities in some jurisdictions seize shipments on that basis. A few jurisdictions channel supply through prescription-only frameworks that do not list the substance by name. Because the material circulates mainly through online vendors, composition and purity are rarely verified before sale. Surveys of unapproved peptide products have reported labels that did not match measured content in a substantial fraction of samples.
Melanotan II is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its structure substitutes a lactam bridge between side chains to increase stability relative to the native hormone. The compound is also known by the shorthand MT-II and by several non-proprietary synonyms used in research catalogues. It is not an approved therapeutic product in any major jurisdiction; material sold under this name is typically offered as a laboratory reagent rather than as a medicine.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic cyclic heptapeptide | Analog of alpha-MSH with an internal lactam bridge |
| Molecular weight | Approximately 1024 daltons | Free base value; salt forms differ |
| Appearance | White to off-white powder | Usually supplied as a lyophilized solid |
| Solubility | Freely soluble in water | Poorly soluble in nonpolar solvents |
| Typical storage | −20 °C, dry, protected from light | Repeated freeze-thaw cycles degrade peptides |
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.
Melanotan-2 is frequently confused with afamelanotide, a linear analogue authorised in the European Union for erythropoietic protoporphyria. The two compounds differ in chain length, ring structure and receptor selectivity, so findings for one cannot be transferred directly to the other. Published controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports. Questions about effect size, dose-response behaviour and long-term safety therefore remain unresolved.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence incorporates a lactam bridge that constrains the peptide into a ring, which increases resistance to enzymatic breakdown relative to the natural hormone. Researchers at the University of Arizona synthesised the compound in the late 1980s and early 1990s while studying pigmentation pathways. It has never received marketing approval from any national medicines regulator. In the scientific literature it is usually described as a laboratory research reagent rather than a therapeutic product.
Human data remain limited and mostly short-term. Reports describe small trials and observational accounts rather than large controlled studies, so questions about dose-response relationships and long-term effects on melanocytes stay open. Whether repeated exposure alters naevus behaviour is not settled in the published record. Researchers also note that self-administered use outside clinical settings makes actual exposure difficult to quantify. Statements about efficacy and safety should therefore be read as preliminary rather than established.
Melanotan II is a synthetic cyclic heptapeptide that acts as an agonist at melanocortin receptors. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous peptide involved in pigment production. The analogue carries a lactam bridge that constrains the ring and slows enzymatic breakdown relative to the native hormone. In research literature it appears under several abbreviations, and naming conventions are not fully standardized. Published descriptions usually place it within the broader melanocortin agonist family.
Receptor binding at MC1R on melanocytes raises intracellular cyclic AMP and increases expression of tyrosinase and related enzymes. The downstream result is greater synthesis of eumelanin, the dark pigment, without ultraviolet exposure acting as the trigger. The compound is not selective, however, and also engages MC3R, MC4R and MC5R, which are expressed in the central nervous system and elsewhere. That lack of selectivity is the explanation usually offered for effects reported outside pigmentation, including appetite suppression and nausea. Selectivity remains a central theme in comparative studies of related peptides.
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.
=== 2014 FDA Form 483 === In December 2014 the FDA issued a Form 483 letter over concerns discovered during an inspection of its Srikakulam facility. No specific violations were mentioned in the letter.
Back pain in pregnancy may also be characterized by pain radiating into the thigh and buttocks, nighttime pain severe enough to wake the patient, pain that is increased at night or pain that is increased during the daytime. Local heat, acetaminophen (paracetamol) and massage can be used to help relieve pain. Avoiding standing for prolonged periods of time is also suggested.
Density: 0.180 kg/m3 at STP (0 °C, 101325 Pa). Atomic weight: 2.0141017926 Da. Mean abundance in ocean water (from VSMOW) 155.76 ± 0.1 atoms of deuterium per million atoms of all isotopes of hydrogen (about 1 atom of in 6420); that is, about 0.015% of all atoms of hydrogen (any isotope) Data at about 18 K for 2H2 (triple point):
== Illegal drugs == An illegal drug trade operates to distribute illegal drugs. The trade of illegal drugs overlaps with trade in contraband of all sorts. Illegal drug distribution does not overlap in obvious ways with the legal trade of legal drugs.
Sources: en.wikipedia.org
=== Later history === In the 1960s, virologist and cancer researcher Chester M. Southam injected HeLa cancer cells into patients at the Jewish Chronic Disease Hospital. When three doctors resigned after refusing to inject patients without their consent, the experiment gained considerable media attention. The NIH was a major source of funding for Southam's research and required all research involving human subjects to obtain their consent before any experimentation. Upon investigating all of their grantee institutions, the NIH discovered that the majority of them did not protect the rights of human subjects. From then on, the NIH has required all grantee institutions to approve any research proposals involving human experimentation with review boards. In 1967, the Division of Regional Medical Programs was created to administer grants for research for heart disease, cancer, and strokes. That same year, the NIH director lobbied the White House for increased federal funding to increase research and the speed with which health benefits could be brought to the people. An advisory committee was formed to oversee the further development of the NIH and its research programs. By 1971, cancer research was in full force, and President Nixon signed the National Cancer Act, initiating a National Cancer Program, President's Cancer Panel, National Cancer Advisory Board, and 15 new research, training, and demonstration centers. Funding for the NIH has often been a source of contention in the US Congress, serving as a proxy for the political currents of the time.
In various diseases, such as type II diabetes, metabolic syndrome, and cancer, normal metabolism is disrupted. The metabolism of cancer cells is also different from the metabolism of normal cells, and these differences can be used to find targets for therapeutic intervention in cancer.
Menthol is a monoterpenoid organic compound that occurs naturally in the oils of certain plants in the mint family, such as corn mint and peppermint. It is a white or clear waxy crystalline substance that is solid at room temperature and melts slightly above. The main form of menthol occurring in nature is (−)-menthol, which is assigned the (1R,2S,5R) configuration. For many people, menthol produces a cooling sensation when inhaled, eaten, or applied to the skin, and mint plants have been used for centuries for topical pain relief and as a food flavoring. Menthol has local anesthetic and counterirritant qualities, and it is widely used to relieve minor throat irritation. Menthol has been demonstrated to cause a subjective nasal decongestant effect without any objective decongestant action, and administration of menthol via a nasal inhaler in humans has also been shown to cause nasal decongestion.
Orthofluorofentanyl (o-fluorofentanyl, 2-fluorofentanyl) is an opioid analgesic that is an analog of fentanyl and has been sold online as a designer drug. While the structural isomer p-fluorofentanyl was one of the first illicit fentanyl analogues identified in 1981, Orthofluorofentanyl did not appear on the illicit market until August 2016.
== Sustainability == Hetero reports its ESG performance annually with reference to the Global Reporting Initiative (GRI), the Sustainability Accounting Standards Board( SASB), and the UN Global Compact. Environment Hetero leads its environment strategy with the stated goal of reaching net zero emissions by 2045. Interim environmental targets include 25% reduction in Scope 1 and Scope 2 emissions by 2030 (with 2022 as a baseline), a 30% increase in the use of renewable energy by 2030, and becoming a Zero Waste to Landfill company in the same year. According to the company’s FY2024-2025 Sustainability report, the company’s Scope 1 emissions were 3,12,435 tCO₂e and Scope 2 emissions were 2,95,020 tCO₂e, resulting in total Scope 1 and Scope 2 emissions of 6,07,455 tCO₂e. Emissions intensity for the year stood at 3.09 tCO₂e per million INR revenue, while biogenic emissions amounted to 72425 tCO₂e. The company also completed its first Scope 3 inventory, covering 13 categories and totalling 1,253,550 tCO₂e. 20% of Hetero’s total energy consumption came from renewable sources. The company recycled 343849 kilolitres of wastewater through Zero Liquid Discharge systems, and recycled 100% of non-hazardous waste, resulting in two sites (Annora and Jeedimetla) receiving Zero Waste to Landfill certification. Social Hetero’s social approach revolves around workforce wellbeing, diversity, inclusion, and occupational safety. As of FY2024-25, Hetero employed 18292 people directly and 10355 people through contract. Women made up 13.63% of direct workforce and 19.28% of contract workers.
Sources: en.wikipedia.org
== Early life and education == Born in Aarberg, Switzerland, Wüthrich was educated in chemistry, physics, and mathematics at the University of Bern before pursuing his PhD supervised by Silvio Fallab at the University of Basel, awarded in 1964.
== Treatment == Some strains of H. influenzae produce beta-lactamases, and are also able to modify its penicillin-binding proteins, so the bacteria have gained resistance to the penicillin family of antibiotics. In severe cases, cefotaxime and ceftriaxone delivered directly into the bloodstream are the elected antibiotics, and, for the less severe cases, an association of ampicillin and sulbactam, cephalosporins of the second and third generation, or fluoroquinolones are preferred. (Fluoroquinolone-resistant strains of H. influenzae have been observed). Macrolides and fluoroquinolones have activity against non-typeable H. influenzae and could be used in patients with a history of allergy to beta-lactam antibiotics. However, macrolide resistance has also been observed.
Indirectly, lightweight nanocomposites for automobiles and other means of transportation could save fuel and reduce materials used for production; nanotechnology-enabled fuel cells and light-emitting diodes (LEDs) could reduce pollution from energy generation and help conserve fossil fuels; self-cleaning nanoscale surface coatings could reduce or eliminate many cleaning chemicals used in regular maintenance routines; and enhanced battery life could lead to less material use and less waste. Green Nanotechnology takes a broad systems view of nanomaterials and products, ensuring that unforeseen consequences are minimized and that impacts are anticipated throughout the full life cycle.
=== Prediction and analysis of drug targets === RNApred: Prediction of RNA binding proteins from its amino acid sequence. ProPrint: Prediction of interaction between proteins from their amino acid sequence. DomPrint: A domain-domain interaction (DDI) prediction server. MycoPrint: A web interface for exploration of the interactome of Mycobacterium tuberculosis H37Rv (Mtb) predicted by the "Domain Interaction Mapping" (DIM) method. ATPint: A server for predicting ATP interacting residues in proteins. FADpred: Identification of FAD interacting residues in proteins. GTPbinder: Prediction of protein GTP interacting residues. NADbinder: Prediction of NAD binding residues in proteins. PreMier: Software for predicting mannose interacting residues in proteins. DMAP: Designing of mutants of antibacterial peptides. icaars: Prediction and classification of aminoacyl tRNA synthetases using PROSITE domains. CBtope: Prediction of conformational B-cell epitope in a sequence from its amino acid sequence. DesiRM: Designing of Complementary and Mismatch siRNAs for silencing a gene. GenomeABC: A server for benchmarking of genome assemblers.
The smallest district of the city is Cit Turin ('Little Turin' in Piedmontese language). This small triangle surrounded by Corso Vittorio Emanuele II, Corso Francia and Corso Inghilterra hosts some high rated residential buildings and is regarded as a prestigious residential neighbourhood by local people.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide modeled on alpha-melanocyte-stimulating hormone. It carries two non-natural substitutions and a cyclic bridge that increase its stability relative to the natural hormone. It circulates as a research chemical and is not an approved medicine.
Melanotan-1, also called afamelanotide, is a shorter linear analog with a different amino acid sequence and no lactam ring. It has been evaluated in formal clinical programs, while melanotan-2 has not. The two are distinct molecules and are not interchangeable.
No. Bremelanotide is a related but distinct cyclic peptide that reached approved status for one specific clinical indication. Melanotan-2 is a separate molecule with its own sequence and properties. Shared ancestry in the melanocortin family does not make them the same substance.
No. No major regulatory agency has granted a marketing authorisation for melanotan II as a medicine. Products sold under this name are generally presented as laboratory reagents and are not subject to the batch-release testing applied to approved drugs.