The short version of regulatory status fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-12-08 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Belongs to the melanocortin agonist family |
| Key substitutions | Nle4 and D-Phe7 | Improve resistance to enzymatic degradation |
| Molecular formula | C50H69N15O9 | Approximately 1024 g/mol |
| Regulatory status | Not approved as a medicine | Distributed as a research chemical |
| Common synonyms | Melanotan II, MT-II, MT-2 | Spelling varies across sources |
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.
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 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.
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.
Receptor studies place melanotan-2 among non-selective melanocortin agonists, binding MC1R, MC3R, MC4R and MC5R rather than a single subtype. Activation of MC1R on cutaneous melanocytes raises tyrosinase activity and shifts pigment synthesis toward eumelanin, which is darker and more photostable than pheomelanin. Central receptors, particularly MC4R, are associated with appetite suppression and with reported effects on sexual function. Because subtype selectivity is low, the same molecule engages pigment, metabolic and vascular pathways at once, and this breadth is a common explanation offered for the range of adverse events described in user reports.
No regulatory authority has approved melanotan-2 for human use, and several countries classify it as a prescription-only or controlled substance, which restricts lawful supply. Material sold online is generally labelled as a research chemical and is not required to meet pharmaceutical standards of identity or purity. Published human data consist mainly of small uncontrolled studies, case reports and adverse-event notifications, so the evidence base is descriptive rather than confirmatory. Whether repeated melanocyte stimulation alters long-term naevus behaviour remains an open question that no completed trial has resolved.
Isosafrole is produced synthetically from safrole. It is not found in nature. Isosafrole comes in two forms, trans-isosafrole and cis-isosafrole. Isosafrole is used as a precursor for the psychoactive drug MDMA (ecstasy). When safrole is metabolized, several metabolites can be identified. Some of these metabolites have been shown to exhibit toxicological effects, such as 1′-hydroxysafrole and 3′-hydroxysafrole in rats. Further metabolites of safrole that have been found in urine of both rats and humans include 1,2-dihydroxy-4-allylbenzene or 1(2)-methoxy-2(1)hydroxy-4-allylbenzene.
incorporates its gross from the 1985 reissue but not from 2002. The total for Avatar's first appearance on the chart includes revenue from the 2010 Special Edition, which represents all of its earnings up to the point it relinquished the record, whereas its second appearance also incorporates revenue from a 2020 re-release in the Asia-Pacific region as well as the 2021 re-release in China which helped it to reclaim the record. Gone with the Wind is likewise represented twice on the chart: the 1940 entry includes earnings from its staggered 1939–1942 release (roadshow/general release/second-run) along with all of its revenue up to the 1961 reissue prior to losing the record to The Sound of Music in 1966; its 1971 entry—after it took back the record—includes income from the 1967 and 1971 reissues but omitting later releases. The Godfather was re-released in 1973 after its success at the 45th Academy Awards, and Jaws was released again in 1976, and their grosses here most likely include earnings from those releases. The Sound of Music, The Godfather, Jaws, Jurassic Park, and Titanic have all increased their earnings with further releases, but they are not included in the totals here because they had already conceded the record prior to being re-released.
The current SI value of the mole is based on the historical definition of the mole as the amount of substance that corresponds to the number of atoms in 12 grams of 12C, which made the molar mass of a compound in grams per mole, numerically equal to the average molecular mass or formula mass of the compound expressed in daltons. With the 2019 revision of the SI, the numerical equivalence is now only approximate, but may still be assumed with high accuracy. Conceptually, the mole is similar to the concept of dozen or other convenient grouping used to discuss collections of identical objects. Because laboratory-scale objects contain a vast number of tiny atoms, the number of entities in the grouping must be huge to be useful for work. The mole is widely used in chemistry as a convenient way to express amounts of reactants and amounts of products of chemical reactions. For example, the chemical equation 2 H2 + O2 → 2 H2O can be interpreted to mean that for each 2 mol molecular hydrogen (H2) and 1 mol molecular oxygen (O2) that react, 2 mol of water (H2O) form. The concentration of a solution is commonly expressed by its molar concentration, defined as the amount of dissolved substance per unit volume of solution, for which the unit typically used is mole per litre (mol/L).
Sources: en.wikipedia.org
== Division of Laboratory Systems == The Division of Laboratory Systems ('DLSs) purpose is to improve the quality of laboratory testing and related practices in the U.S. and globally through the development and evaluation of innovative training, technical standards, practice guidelines, and reference materials. Major Products or Services provided by DLS include:
== Peptidase inhibitor == Iodoacetamide is an irreversible inhibitor of all cysteine peptidases, with the mechanism of inhibition occurring from alkylation of the catalytic cysteine residue (see schematic). In comparison with its acid derivative, iodoacetate, iodoacetamide reacts substantially faster. This observation appears contradictory to standard chemical reactivity, however the presence of a favourable interaction between the positive imidazolium ion of the catalytic histidine and the negatively charged carboxyl-group of the iodoacetate is the reason for the increased relative activity of iodoacetamide.
Osavampator (developmental code names TAK-653 and NBI-1065845) is an experimental drug being investigated as a treatment for treatment-resistant depression. It is being developed by Neurocrine Biosciences and Takeda Pharmaceuticals (Millennium Pharmaceuticals, Inc.). Takeda Pharmaceuticals discovered the molecule originally, and holds exclusive right to market the drug in Japan, while Neurocrine Biosciences holds the right to market it to the rest of the world.
Sources: en.wikipedia.org
== The cladistic turn (1970s–1990s) == By the late 20th century lichen systematics adopted the quantitative, computer-aided methods gaining ground across biology. Numerical taxonomy (phenetics) and cladistics entered lichenology, paralleling their uptake in plant and animal studies. Researchers replaced qualitative judgement with data matrices that coded morphological, chemical, and anatomical characters, then applied algorithms to infer relationships. Phenetic studies of the 1970s grouped lichens with clustering routines; in the 1980s Willi Hennig's cladistics shifted focus to shared-derived characters (synapomorphies) for reconstructing evolutionary trees. The shift required clear definitions of characters and explicit decisions about which traits were primitive or derived. Analyses became repeatable and easy to update as new characters or taxa were added. Robert Lücking (2020) called this methodological turn a milestone on par with the invention of the microscope for taxonomy. The new methods added rigour and standardization, aligning lichen systematics with broader evolutionary biology. Manuals on numerical and cladistic techniques were widely adopted, and phylogenetic workshops became regular features of lichen conferences. Cladistic rigour prompted a reassessment of single-trait classifications. Earlier systems frequently anchored families or genera on a single trait—spore septation, a particular metabolite, and so on. Cladistic analyses showed that such one-character groupings often masked true relationships.
Arrestins are elongated molecules, in which several intra-molecular interactions hold the relative orientation of the two domains. Unstimulated cell arrestins are localized in the cytoplasm in a basal inactive conformation. Active phosphorylated GPCRs recruit arrestin to the plasma membrane. Receptor binding induces a global conformational change that involves the movement of the two arrestin domains and the release of its C-terminal tail that contains clathrin and AP2 binding sites. Increased accessibility of these sites in receptor-bound arrestin targets the arrestin-receptor complex to the coated pit. Arrestins also bind microtubules (part of the cellular skeleton), where they assume yet another conformation, different from both free and receptor-bound form. Microtubule-bound arrestins recruit certain proteins to the cytoskeleton, which affects their activity and/or redirects it to microtubule-associated proteins. Arrestins shuttle between cell nucleus and cytoplasm. Their nuclear functions are not fully understood, but it was shown that all four mammalian arrestin subtypes remove some of their partners, such as protein kinase JNK3 or the ubiquitin ligase Mdm2, from the nucleus. Arrestins also modify gene expression by enhancing transcription of certain genes.
Many drugs are metabolised by a set of liver enzymes called CYP450s. The activity of these enzymes would determine the rate of pro-drug activation and the rate of inactivation of active drugs. For example, warfarin, a commonly used anticoagulant drug in atrial fibrillation, is metabolised by an enzyme called CYP2C9. Phenytoin, a CYP2C9 inducer, would increase its activity and the rate of warfarin breakdown, thereby reducing its efficacy. Patients should avoid the co-administration of warfarin and phenytoin. In cases where both drugs must be used together, warfarin dosing may be titrated up to cope with the reduced efficacy. The kidney excretes most drugs through urine. Since urine is weakly alkaline in nature, weakly acid drugs would ionise in urine, making it difficult for them to be reabsorbed. Therefore, in cases of aspirin (weak acid) toxicity, injecting intravenous sodium bicarbonate could increase urine pH, thereby increasing the excretion of aspirin through urine. A similar approach can be used in other weakly acidic drug toxicity.
Sources: en.wikipedia.org
It is a synthetic cyclic peptide designed as an analog of alpha-melanocyte-stimulating hormone. It acts on melanocortin receptors and is best known from research into pigmentation. It is not an approved pharmaceutical product.
No regulatory agency has approved it for any indication. It is encountered as a research chemical sold outside pharmaceutical supply chains. Products marketed this way are not subject to the manufacturing and labeling requirements that apply to approved drugs.
Reports describe increased skin pigmentation as well as side effects such as nausea, flushing, and changes to existing moles. Much of the evidence comes from small studies and case reports rather than large trials. The long-term safety profile is therefore uncertain.
Major regulatory agencies have not approved it for any indication. Some countries permit it only under prescription frameworks, while others classify it as a controlled substance.