If you have been reading about post-marketing surveillance 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.
Last reviewed on 2026-03-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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.
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 |
|---|---|---|
| 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 |
Routine characterisation relies on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, using a C18 column and a water-acetonitrile gradient containing trifluoroacetic acid. Electrospray ionisation mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidised by-products that co-elute poorly. Sequence and stereochemistry require additional work, such as peptide mapping or amino acid analysis, because a chromatographic purity figure alone does not distinguish a diastereomer from the target peptide. Independent testing of research-grade material frequently shows measured content below the stated label, so a certificate of analysis is best read together with the method that produced it.
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.
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.
Pharmacologically, melanotan-2 behaves as a non-selective agonist across the melanocortin receptor family. Binding at MC1R on dermal melanocytes promotes eumelanin synthesis, which underlies the tanning response described in early human work. Activity at the centrally expressed MC4R receptor is associated with reported effects on appetite and erectile function. Because the peptide does not discriminate strongly among receptor subtypes, attributing any single observed effect to one receptor pathway is generally not possible without selective antagonists or receptor knockout models.
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.
== Advantages and limitations == One of the main advantages of CI over EI is the reduced fragmentation as noted above, which for more fragile molecules, results in a peak in the mass spectrum indicative of the molecular weight of the analyte. This proves to be a particular advantage for biological applications where EI often does not yield useful molecular ions in the spectrum. The spectra given by CI are simpler than EI spectra and CI can be more sensitive than other ionization methods, at least in part to the reduced fragmentation which concentrates the ion signal in fewer and therefore more intense peaks. The extent of fragmentation can be somewhat controlled by proper selection of reagent gases. Moreover, CI is often coupled to chromatographic separation techniques, thereby improving its usefulness in identification of compounds. As with EI, the method is limited to compounds that can be vapourized in the ion source. The lower degree of fragmentation can be a disadvantage in that less structural information is provided. Additionally, the degree of fragmentation and therefore the mass spectrum, can be sensitive to source conditions such as pressure, temperature, and the presence of impurities (such as water vapour) in the source. Because of this lack of reproducibility, libraries of CI spectra have not been generated for compound identification.
gamete A haploid cell that is the meiotic product of a progenitor germ cell and the final product of the germ line in sexually reproducing multicellular organisms. Gametes are the means by which an organism passes its genetic information to its offspring; during fertilization, two gametes (one from each parent) are fused into a single diploid zygote.
The aligned region is referred to as a homeomorphic domain, and this region may comprise several smaller homology domains that are shared with other families. Families may be further subdivided into subfamilies or grouped into superfamilies based on respective higher or lower levels of sequence similarity. The SCOP database reports 1296 families and the CATH database (version 1.7 beta), reports 1846 families. When the sequences of proteins with the same function are examined in greater detail, some are found to share high sequence similarity. They are obviously members of the same family by the above criteria. However, others are found that have very little, or even insignificant, sequence similarity with other family members. In such cases, the family relationship between two distant family members A and C can often be demonstrated by finding an additional family member B that shares significant similarity with both A and C. Thus, B provides a connecting link between A and C. Another approach is to examine distant alignments for highly conserved matches. At a level of identity of 50%, proteins are likely to have the same three-dimensional structure, and the identical atoms in the sequence alignment will also superimpose within approximately 1 Å in the structural model. Thus, if the structure of one member of a family is known, a reliable prediction may be made for a second member of the family, and the higher the identity level, the more reliable the prediction.
Since u needs to be finite at r = 0, c1 = 0. The no slip boundary condition at the pipe wall requires that u = 0 at r = R (radius of the pipe), which yields c2 = GR2/4μ. Thus we have finally the following parabolic velocity profile:
Synthetic recombinant human TSH alpha (rhTSHα or simply rhTSH) or thyrotropin alfa (INN) is manufactured by Genzyme Corp under the trade name Thyrogen. It is used to manipulate endocrine function of thyroid-derived cells, as part of the diagnosis and treatment of thyroid cancer. A Cochrane review compared treatments using recombinant human thyrotropin-aided radioactive iodine to radioactive iodine alone. In this review it was found that the recombinant human thyrotropin-aided radioactive iodine appeared to lead to a greater reduction in thyroid volume at the increased risk of hypothyroidism. No conclusive data on changes in quality of life with either treatments were found.
Sources: en.wikipedia.org
=== Sources === For the most part, vitamins are obtained from the diet, but some are acquired by other means: for example, microorganisms in the gut flora produce vitamin K and biotin; and one form of vitamin D is synthesized in skin cells when they are exposed to a certain wavelength of ultraviolet light present in sunlight. Humans can produce some vitamins from precursors they consume: for example, vitamin A is synthesized from beta carotene; and niacin is synthesized from the amino acid tryptophan. Vitamin C can be synthesized by some species but not by others. Vitamin B12 is the only vitamin or nutrient not available from plant sources. The Food Fortification Initiative lists countries which have mandatory fortification programs for vitamins folic acid, niacin, vitamin A and vitamins B1, B2 and B12.
The three substrates of this enzyme are succinic semialdehyde, oxidised nicotinamide adenine dinucleotide (NAD+) and water. Its products are succinic acid, reduced NADH, and a proton. This enzyme can use the alternative cofactor, nicotinamide adenine dinucleotide phosphate. This enzyme belongs to the family of oxidoreductases, specifically those acting on the aldehyde or oxo group of donor with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is succinate-semialdehyde:NAD(P)+ oxidoreductase. Other names in common use include succinate semialdehyde dehydrogenase (nicotinamide adenine, dinucleotide (phosphate)), and succinate-semialdehyde dehydrogenase [NAD(P)+]. This enzyme participates in 3 metabolic pathways: glutamate metabolism, tyrosine metabolism, and butanoate metabolism.
Information found in PPIs databases supports the construction of interaction networks. Although the PPI network of a given query protein can be represented in textbooks, diagrams of whole cell PPIs are frankly complex and difficult to generate. One example of a manually produced molecular interaction map is the Kurt Kohn's 1999 map of cell cycle control. Drawing on Kohn's map, Schwikowski et al. in 2000 published a paper on PPIs in yeast, linking 1,548 interacting proteins determined by two-hybrid screening. They used a layered graph drawing method to find an initial placement of the nodes and then improved the layout using a force-based algorithm. Bioinformatic tools have been developed to simplify the difficult task of visualizing molecular interaction networks and complement them with other types of data. For instance, Cytoscape is an open-source software widely used and many plugins are currently available. Pajek software is advantageous for the visualization and analysis of very large networks. Identification of functional modules in PPI networks is an important challenge in bioinformatics. Functional modules means a set of proteins that are highly connected to each other in PPI network. It is almost similar problem as community detection in social networks. There are some methods such as Jactive modules and MoBaS. Jactive modules integrate PPI network and gene expression data where as MoBaS integrate PPI network and Genome Wide association Studies.
Top-down proteomics is a method of protein identification capable of identifying and quantitating unique proteoforms through the analysis of intact proteins. The name is derived from the similar approach to DNA sequencing. During mass spectrometry, intact proteoforms are typically ionized by electrospray ionization and analysed using a variety of mass analysers, including Orbitraps, Ion Cyclotrons and Time-Of-Flight. Effective fractionation is critical for sample handling before mass-spectrometry-based proteomics. Typical proteome analysis routinely involves digesting intact proteins followed by inferred protein identification using mass spectrometry (MS; Bottom Up proteomics). Top-down proteomics using mass spectrometry interrogates protein structure through measurement of a proteoform's intact mass followed by direct ion dissociation in the gas phase. Top Down proteoform analysis can also be achieved through resolution (separation) of the proteoform from all other proteoforms and then applying peptide-centric LC-MS/MS to characterise the isolated proteoform. A single gene can be coded for many protein products (e.g. via alternative splicing; post-transcriptional and -translational processing) and the resulting canonical amino acid sequences (i.e. 'proteins' or more correctly Open Reading Frame (ORF) products) can be further modified by any number of post-translational modifications (PTM) or non-physiological adducts. These varied protein species or proteoforms define proteomes and are the functional entities underlying biological processes.
=== Medical plastic === Medical plastics include a wide range of products, especially single-use plastics like storage bags to pharmaceutical containers, that expose patients and healthcare workers to MNPs. Face masks and respirators are often made of plastic, primarily polyethylene and other synthetic polymers. Studies have shown that MNPs can be inhaled from wearing surgical or N95 masks, and the amount of MNPs released greatly increases when the same mask is worn repeatedly.
Sources: en.wikipedia.org
=== Tentoxin === Tentoxin is most commonly known as a naturally occurring phytotoxic cyclic tetra-peptide that is excreted by fungi of the Alternaria alternata family. There were four total syntheses of tentoxin that were published to this day that gave very poor total yields. These poor yields were mainly due to the introduction of the dehydro amino acid, more specifically the cyclization step. There was a method developed in order to stereospecifically introduce Z-dehydrophenylalanine by a modified Erlenmeyer adolization reaction. An aldol reaction is a transformation that is due to the dimerization of an aldehyde (or ketone) to a beta-hydroxy aldehyde (or ketone) by alpha C-H addition of one reactant molecule to the carbonyl group of a second reactant molecule. This reaction requires at least one of the reactants to have hydrogens. The precursor of tentoxin, the linear tetrapeptide (Boc-R1Ala-Leu-R2ΔZPhe-Gly-OMe), was obtained from Boc-Leu-Gly-OH with a 72% yield. This linear tetrapeptide with carbon-14 was utilized to study the four cyclization reagents, DPPA, DCC-PfpOH, HBTU, and HATU. By doing so, this gave the tentoxin an 81% cyclization yield.
== Interactions == Naltrexone, a non-selective opioid receptor antagonist including of the κ-opioid receptor (KOR), blocks the hallucinogenic and physiological effects of salvinorin A in humans. Conversely, the serotonin 5-HT2A receptor antagonist ketanserin was ineffective.
==== Novel agents ==== Several newer agents, including temozolomide and bendamustine, have activity in relapsed SCLC. Of note, temozolomide yielded a response rate of 38% for brain metastases due to SCLC. In a clinical trial of 50 patients, a combination of olaparib and temozolomide in relapsed small-cell lung cancer yielded an overall response rate of 41.7%, median progression-free survival of 4.2 months, and overall survival was 8.5 months. Lurbinectedin showed an increased overall survival rate in relapsed small cell lung cancer in a trial. Lurbinectedin is As of 2019 available in the U.S. under an expanded access program (EAP). Trilaciclib, a CKD4/6 inhibitor, reduces chemotherapy-induced toxicity in patients being treated for small-cell lung cancer. In 2021, the FDA approved trilaciclib (Cosela) as a treatment to reduce the frequency of chemotherapy-induced myelosuppression for patients receiving certain types of chemotherapy for extensive-stage small-cell lung cancer.
== Mental health assistance == Due to the discrimination they face, trans individuals often present significant mental health disparities. Among them, it is estimated that 32-50% of trans individuals across various countries have attempted suicide, with this high prevalence attributed to factors such as victimization, bullying, violence, social and familial rejection, as well as discrimination in different public sectors. Other than gender dysphoria, trans individuals are also affected by mental health diagnoses, such as major depression and generalized anxiety, at far greater rates than the non-trans population. Whilst gender-affirming care has a positive impact on trans individuals' mental health and may lessen several symptoms, the psychological improvements of such care are often limited by the minority stressors affecting the trans population. Due to these factors, mental health assistance through means such as psychotherapy may play an important role in addressing trans patients' mental health. Mental health assessments and treatment may be conducted prior to the initiation of gender-affirming care as a means of ensuring the patient's informed consent and complementing medical transition. Pyschotherapy as a requirement for the inititation of affirmative medical care today is discouraged by trans health care protocols, as are approaches attempting to change the patient's identity or skew self-exploration towards one particular direction.
== Management == Biomedical waste must be properly managed and disposed of to protect the environment, general public and workers, especially healthcare and sanitation workers who are at risk of exposure to biomedical waste as an occupational hazard. Steps in the management of biomedical waste include generation, accumulation, handling, storage, treatment, transport and disposal. The development and implementation of a national waste management policy can improve biomedical waste management in health facilities in a country.
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. 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.