Everything below concerns analytical characterisation. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-08-12. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Melanotan II holds no marketing authorisation from the Food and Drug Administration, the European Medicines Agency, the UK Medicines and Healthcare products Regulatory Agency or Australia's Therapeutic Goods Administration. Products sold under that name are treated as unapproved new drugs, and their sale or import is prohibited in several jurisdictions. Other countries classify the peptide as a prescription-only medicine or place it among controlled substances, so the legal position changes with the destination market. No pharmacopoeial monograph supplies an official specification, because the material is not a licensed pharmaceutical. Consequently, products offered online are not manufactured to a shared public standard.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Unapproved in the US, EU and Australia | Sale and import restricted; no licensed product |
| Typical test matrices | Urine, serum, seized powder | Urinary detection window is short |
| Primary identification method | LC-MS/MS against a reference standard | High-resolution mass used for confirmation |
| Data sources in the literature | Small trials, case reports, pharmacovigilance | No registrational trial dataset exists |
| Common marketing names | Melanotan 2, MT-II, MT-2 | Label content may not match declared peptide |
Scientific discussion of Melanotan-2 spans pharmacology, dermatology, and public-health literature. Laboratory studies examine its receptor binding and cellular effects, while clinical reports describe outcomes observed after unregulated use. These two bodies of work differ in rigour and intent. Peer-reviewed trials of the compound as a medicine are limited, so much of the available information comes from case reports and surveillance data. Authors frequently note the gap between experimental findings and real-world use.
Reported observations after unregulated use include shifts in skin pigmentation and, in some accounts, unintended changes to moles and other lesions. Whether these outcomes are causally linked to the compound, and how often they occur, remain open questions because controlled data are scarce. The absence of standardised dosing and verified product purity complicates interpretation. Researchers have called for better surveillance and analytical characterisation of samples obtained outside regulated channels. Conclusions drawn from anecdotal evidence should be treated as provisional.
Melanotan-2 has not received marketing authorisation from major regulatory agencies for any therapeutic indication. Several jurisdictions classify it as a prescription-only medicine or a controlled substance when supplied for human use. Because approved products do not exist, material sold online usually sits outside pharmaceutical supply chains and formal quality oversight. Regulators have issued public notices describing the compound as unapproved. Enforcement varies, and the legal position differs between countries, which complicates any single general statement about its status.
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.
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.
Regulatory treatment varies by jurisdiction and has changed over time. In several countries the peptide is handled as an unapproved prescription medicine, and import or sale for human use is restricted, while elsewhere it falls under poisons or controlled-substance schedules. Enforcement activity against online vendors has been reported in Australia, New Zealand, the United Kingdom and the United States. Scholarly writing discusses melanotan-2 chiefly as an experimental tool and as a case study in unregulated peptide supply, and its precise legal position in any given country should be checked against current national schedules.
Lyophilised melanotan-2 is comparatively robust when kept dry, cold and dark, and a desiccated powder stored at minus twenty degrees Celsius or below is generally expected to retain its chemical integrity for extended periods. In solution the peptide is far less stable, with degradation proceeding through oxidation of tryptophan and histidine residues, hydrolysis adjacent to the lactam bridge, and aggregation at higher concentrations. Repeated freeze-thaw cycling accelerates loss of the parent peak. Working aliquots are therefore prepared once, held cold, and used without letting the stock return to ambient temperature.
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.
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.
Scientific investigation has not found any histological or physiological evidence for traditional Chinese concepts such as qi, meridians, and acupuncture points. It is a generally held belief within the acupuncture community that acupuncture points and meridians structures are special conduits for electrical signals but no research has established any consistent anatomical structure or function for either acupuncture points or meridians. The scientific evidence for the anatomical existence of either meridians or acupuncture points is not compelling. Stephen Barrett of Quackwatch writes that, "TCM theory and practice are not based upon the body of knowledge related to health, disease, and health care that has been widely accepted by the scientific community. TCM practitioners disagree among themselves about how to diagnose patients and which treatments should go with which diagnoses. Even if they could agree, the TCM theories are so nebulous that no amount of scientific study will enable TCM to offer rational care."
== History == The Diet of Hungary (Hungarian: Országgyűlés) was a legislative institution in the medieval kingdom of Hungary from the 1290s, and in its successor states, Royal Hungary and the Habsburg kingdom of Hungary throughout the Early Modern period. The name of the legislative body was originally "Parlamentum" during the Middle Ages, the "Diet" expression gained mostly in the Early Modern period. It convened at regular intervals with interruptions during the period of 1527 to 1918, and again until 1946. In 1608, a bicameral legislature was enacted as the Royal Hungarian Diet, dividing the main board and the lower board (the board of envoys). Members of the main board (the upper house) were the high nobles and high priests (archbishops and bishops). The lower board was attended by representatives of the common nobility, clergy and civil order: elected representatives of the noble county, delegates of the free royal cities and representatives of the lower Church representatives. Approximately 10% of the total voting age population could vote for the elected delegates of the lower board (5% county nobility, 5% residents of free royal cities). The election of the noble delegates (1 delegate from each county) took place in the county delegate elections, after a long, noisy, courtier campaign, at the county hall. Delegates received voting instructions from county assemblies. The parliament consisted of about 500 people in the 17th–18th centuries.
== Lymphocytes == Lymphocytes are just one group of cells that function as part of the immune system. More of this group travel around the lymphatic system than in the blood network. Two types of lymphocytes are present in the bloodstream, which are the B cells and the T cells. B cells are wandering cells that are antibody factories. They are capable of producing molecules that can recognize and bond to specific types of molecules present in infectious organisms or substances that the body identifies as foreign. Every individual B cell makes only one particular type of antibody, specific to only one type of foreign substance. For example, where one cell produces antibody against one of the many viral causes of a cold, another cell's antibodies will ignore the presence of the same virus completely. Normally, the body contains many different B cells, specialized for a specific invader, but only has low levels of each type circulating. When an invader manages to break past other defenses, like the skin or digestive tract into the body, then the circulating B cells that target that particular foreigner multiply up and produce more antibody. Special forms of B cell called plasma cells produce antibodies; little versions of the specialized B cells, called memory B cells, remain stored in lymph glands prepared for the next invasion by the foreigner. Although the products of B cells, the antibodies, stick onto their target invader, they most often do not kill the invader. This job falls to other types of lymphocytes called T cells.
Sources: en.wikipedia.org
For a high score, or pretest probability, a D-dimer will make little difference and anticoagulant therapy will be initiated regardless of test results, and additional testing for DVT or pulmonary embolism may be performed. For a moderate or low score, or pretest probability: A negative D-dimer test will virtually rule out thromboembolism: the degree to which the D-dimer reduces the probability of thrombotic disease is dependent on the test properties of the specific test used in the clinical setting: most available D-dimer tests with a negative result will reduce the probability of thromboembolic disease to less than 1% if the pretest probability is less than 15-20%. Chest computed tomography (CT angiography) should not be used to evaluate pulmonary embolism for persons with negative results of a D-dimer assay. A low pretest probability is also valuable in ruling out PE. If the D-dimer reads high, then further testing (ultrasound of the leg veins or lung scintigraphy or CT scanning) is required to confirm the presence of thrombus. Anticoagulant therapy may be started at this point or withheld until further tests confirm the diagnosis, depending on the clinical situation. In some hospitals, they are measured by laboratories after a form is completed showing the probability score and only if the probability score is low or intermediate. This reduces the need for unnecessary tests in those who are high-probability. Performing the D-dimer test first can avoid a significant proportion of imaging tests and is less invasive.
The highest density is observed in the upper 10% of the stroma. The number of keratocytes declines with age, at a rate approximately 0.45% per year. After an injury to the cornea, some keratocytes undergo apoptosis, prompted by the signaling molecules secreted by the upper layers, such as IL1 alpha and TNF-alpha. Other neighbouring keratocytes, when acted upon by the same molecules, become active, proliferate and start synthesizing matrix metalloproteinases that cause tissue remodeling. These activated cells are designated in different sources either as "active keratocytes" or "fibroblasts" or are said to assume a "repair phenotype". After heavier injuries or at the advanced stages of healing process a number of keratocytes transforms into myofibroblasts actively secreting ECM components; this transformation is thought to be caused by TGF-beta. As soon as the basement membrane of corneal epithelium is restored, TGF beta inflow into the stroma drastically decreases and myofibroblasts disappear, after which the remaining activated keratocytes continue for some time to reshape the extracellular matrix, secreting IL1-alpha in order to maintain their "repair phenotype". Apoptosis of keratocytes, either in quiescent or active state, is a process that attracts special attention. In a healthy cornea the programmed cell death is a rare occasion, but immediately after an injury to the uppermost layer keratocytes directly under the injury site commit apoptosis.
==== Single crown implants (5-year) ==== Implant survival: 96.8 percent Crown survival: metal-ceramic: 95.4 percent; all-ceramic: 91.2 percent; cumulative rate of ceramic or acrylic veneer fracture: 4.5 percent Peri-implantitis: 9.7 percent up to 40 percent Peri-implant mucositis: 50 percent Implant fracture: 0.14 percent Screw or abutment loosening: 12.7 percent Screw or abutment fracture: 0.35 percent
The Aviation Safety Reporting System (ASRS) collects voluntarily submitted aviation safety incident/situation reports from pilots, controllers and others. The ASRS uses reports to identify system deficiencies, issue alert messages, and produce two publications, CALLBACK, and ASRS Directline. The collected information is made available to the public, and is used by the FAA, NASA and other organizations working in research and flight safety.
Sources: en.wikipedia.org
=== Europe === Following discussions on the safety of certain pharmaceutical products derived from kava and sold in Germany, the EU imposed a temporary ban on imports of kava-based pharmaceutical products in 2002. The sale of kava plant became regulated in Switzerland, France, and in prepared form in the Netherlands. Some Pacific island states, which had been benefiting from the export of kava to the pharmaceutical companies, have attempted to overturn the EU ban on kava-based pharmaceutical products by invoking international trade agreements: Fiji, Samoa, Tonga, and Vanuatu argued at the WTO that the ban was imposed with insufficient evidence. The pressure prompted Germany to reconsider the evidence base for banning kava-based pharmaceutical products. On 10 June 2014, the German Administrative Court overturned the 2002 ban, making selling kava as a medicine legal, albeit strictly regulated; personal possession of kava has never been illegal. In Germany, kava-based pharmaceutical preparations are currently prescription drugs. Furthermore, patient and professional information brochures have been redesigned to warn about potential side effects. These strict measures have been opposed by some of the leading kava scientists. In early 2016, a court case was filed against the Bundesinstitut für Arzneimittel und Medizinprodukte (BfArM/German Federal Institute for Drugs and Medical Devices), arguing that the new regulatory regime is too strict and not justified.
Telisotuzumab vedotin, sold under the brand name Emrelis, is an antibody drug conjugate used for the treatement of non-small cell lung cancer. Telisotuzumab vedotin is a c-Met-directed antibody and microtubule inhibitor conjugate. It was developed by AbbVie. The most common adverse reactions include peripheral neuropathy, fatigue, decreased appetite, and peripheral edema. The most common grade 3 or 4 laboratory abnormalities include decreased lymphocytes, increased glucose, increased alanine aminotransferase, increased gamma glutamyl transferase, decreased phosphorus, decreased sodium, decreased hemoglobin, and decreased calcium. Telisotuzumab vedotin was approved for medical use in the United States in May 2025. The US Food and Drug Administration considers it to be a first-in-class medication.
== P == Painting – Classic period Maya paintings, found in the archaeological sites of Cacaxtla and Bonampak, are some of the most refined paintings ever to come out of the ancient Americas. Besides the Maya, other indigenous civilizations were also known for their wall paintings, including the Aztec and the Navajo, who developed the art of sand painting.
Most pharmaceuticals are small molecules - they are equivalent in the literature, although some drugs can be proteins (e.g., insulin and other biologic medical products). With the exception of therapeutic antibodies, many proteins are degraded if administered orally and most often cannot cross cell membranes. Small molecules are more likely to be absorbed, although some of them are only absorbed after oral administration if given as prodrugs. One advantage that small-molecule drugs (SMDs) have over "large-molecule" biologics is that many small molecules can be taken orally whereas biologics generally require injection or another parenteral administration. Small molecule drugs are also typically simpler to manufacture and cheaper for the purchaser. A downside is that not all targets are amenable to modification with small-molecule drugs; bacteria and cancers are often resistant to their effects.
The slide shows at (1) an epithelial cell infected by Chlamydia pneumoniae; their inclusion bodies shown at (3); an uninfected cell shown at (2) and (4) showing the difference between an infected cell nucleus and an uninfected cell nucleus. Epithelium grown in culture can be identified by examining its morphological characteristics. Epithelial cells tend to cluster together, and have a "characteristic tight pavement-like appearance". But this is not always the case, such as when the cells are derived from a tumor. In these cases, it is often necessary to use certain biochemical markers to make a positive identification. The intermediate filament proteins in the cytokeratin group are almost exclusively found in epithelial cells, so they are often used for this purpose. Cancers originating from the epithelium are classified as carcinomas. In contrast, sarcomas develop in connective tissue. When epithelial cells or tissues are damaged from cystic fibrosis, sweat glands are also damaged, causing a frosty coating of the skin.
Sources: en.wikipedia.org
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.
Reversed-phase LC-MS/MS is the usual approach for both identification and quantitation. High-resolution mass spectrometry and peptide mapping serve as confirmatory methods. Immunoassays are rarely used alone because of cross-reactivity.
Published testing of seized and purchased samples frequently reports discrepancies between declared and measured peptide content. Counter-ion content and residual solvents add further variation. Independent analysis is the only way to confirm composition.
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.