Everything below concerns regulatory status. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-08-19. Numbers and descriptions here follow the published literature rather than marketing material.
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controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports.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.
The peptide acts as a non-selective agonist at melanocortin receptors, showing affinity for MC1R, MC3R, MC4R and MC5R. Activation of MC1R on melanocytes drives the conversion of tyrosine into melanin and shifts production toward the darker eumelanin form. MC4R signalling in the central nervous system is linked to appetite and energy balance, which helps explain why reduced food intake appeared in early human studies. Effects on MC4R and on vascular tone also account for the erectile responses recorded as unexpected findings in those same trials.
Published research on the compound remains limited. Much of the human data comes from small, early-stage studies rather than large controlled trials, and several questions about effects and variability between individuals remain open. Investigators have examined receptor activity, pigment pathways, and related physiological responses in laboratory and animal models. Findings from those models do not automatically translate to human outcomes. Reviews frequently note the scarcity of rigorous clinical evidence and call for better-characterized study material.
Because the substance circulates mainly through informal markets, verification is a recurring theme in technical discussion. Independent analyses have found that labeled content and actual content can diverge, and that purity varies between samples. Analytical laboratories use reversed-phase chromatography to separate components and mass spectrometry to confirm identity. Isotope-labeled internal standards improve quantification in complex matrices. Such methods describe what a sample contains but say nothing about its sterility, lawful status, or suitability for any use. Open questions remain about how consistently testing is applied across the supply chain.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Alpha-MSH analogue with a lactam ring |
| Molecular formula | C50H69N15O9 | Commonly cited value for the neutral peptide |
| Molecular weight | 1024.18 g/mol | Calculated for the free molecule |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water, DMSO and ethanol | Dissolution in pure water is often slow |
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.
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.
Stationarity implies that the marginal (equilibrium) probabilities of nucleotides or amino acids remain constant over time. In a phylogenetic tree, this means the base composition is assumed to be the same across all lineages. Reversibility indicates that the process of substitution is symmetric in time. Formally, the probability of being in state i and changing to state j equals the probability of being in state j and changing to state i under the stationary distribution. This property allows the tree likelihood to be computed without knowledge of the root position. Homogeneity means that the substitution process (i.e., the rate matrix and stationary distribution) is the same across all branches of the tree. These assumptions enable the use of a single Markov model across the phylogeny and greatly reduce the complexity of tree estimation. Reversibility, in particular, is commonly used because it simplifies the likelihood calculations by removing the need to infer the root.
The SADF believed that a covert sabotage operation was possible, as long as the destruction was not attributable to South Africa and a credible cover story could be used to link the attack to a domestic Angolan movement such as UNITA or the Front for the Liberation of the Enclave of Cabinda (FLEC). An attack on the oil platforms was ruled out, as this was beyond the capabilities of either UNITA or FLEC, so the SADF opted to infiltrate the refinery's oil storage facilities and mine the fuel tanks. The damage incurred would cripple Angola's ability to finance its military operations and give it greater economic incentive to accede to South African demands in the ongoing negotiations rather than risk returning to war. The sabotage mission received the code name Operation Argon, and 15 South African special forces operators deployed to Cabinda by sea in May 1985. They were discovered by a FAPLA patrol during the infiltration attempt, and two of the raiders were shot dead with a third, Captain Wynand Petrus du Toit, being captured. Under interrogation, du Toit confessed that the objective of Argon was to sabotage the storage tanks at Cabinda Gulf. The South African government disavowed du Toit and denied responsibility, but General Viljoen later confirmed the SADF's role in the operation. Consequently, the ceasefire imposed as a result of the Lusaka Accords collapsed, and further peace talks were abandoned. The diplomatic repercussions of Operation Argon's failure were immense.
The leak benefits both Jesse financially and Aurore politically, but Gus is fired by Aurore when he lets slip that he was responsible. Jesse subsequently hires Gus as his assistant. In series 3, Rob mentions that Gus is working for a VC fund out of Palo Alto, California.
=== Allergens === Both centipede bites and centipede-containing medicine can cause allergic reactions, yet no natural centipede allergen has been characterized and officially identified until 2021. The novel allergen found in S. mutilans, Sco m 5, was the first natural centipede allergen to be identified and characterized by Lan et al. It was found that Sco m 5 can promote the degranulation of mast cells (i.e. degranulation of mast cells is associated with edema at the respiratory tract). Centipedes used in clinical practice are required to be boiled before administration, and it is whether to keep or discard the head of centipedes in medical uses remained controversial, as the head contains the venom glands.
Sources: en.wikipedia.org
=== General Features === Recently emerged de novo genes differ from established genes in a number of ways. Across a broad range of species, young and/or taxonomically restricted genes have been reported to be shorter in length than established genes, more positively charged, faster evolving, and to be less expressed. Although these trends could be a result of homology detection bias, a reanalysis of several studies that accounted for this bias found that the qualitative conclusions reached were unaffected. Another feature includes the tendency for young genes to have their hydrophobic amino acids more clustered near one another along the primary sequence. The expression of young genes has also been found to be more tissue- or condition-specific than that of established genes. In particular, relatively high expression of de novo genes was observed in male reproductive tissues in Drosophila, stickleback, mice, and humans, and, in the human brain. In animals with adaptive immune systems, higher expression in the brain and testes may be a function of the immune-privileged nature of these tissues. An analysis in mice found specific expression of intergenic transcripts in the thymus and spleen (in addition to the brain and testes). It has been proposed that in vertebrates de novo transcripts must first be expressed in tissues lacking immune cells before they can be expressed in tissues that have immune surveillance.
Chemist James Young in 1847 noticed a natural petroleum seepage in the coal mine at Riddings, Derbyshire, from which he distilled a light thin oil suitable for use as lamp oil, at the same time obtaining a more viscous oil suitable for lubricating machinery. In 1848, Young set up a small business refining crude oil. Young eventually succeeded (by distilling cannel coal at low heat) in creating a fluid resembling petroleum, which when treated in the same way as the seep oil gave similar products. Young found that by slow distillation he could obtain several useful liquids from it, one of which he named "paraffine oil" because at low temperatures it congealed into a substance resembling paraffin wax. The production of these oils and solid paraffin wax from coal formed the subject of his patent dated October 17, 1850. In 1850, Young & Meldrum and Edward William Binney entered into partnership under the title of E.W. Binney & Co. at Bathgate in West Lothian and E. Meldrum & Co. at Glasgow; their works at Bathgate were completed in 1851 and became the first truly commercial oil-works in the world with the first modern oil refinery. The demand for petroleum as a fuel for lighting in North America and around the world quickly grew. The first oil well in the Americas was drilled in 1859 by Edwin Drake at what is now called the Drake Well in Cherrytree Township, Pennsylvania. There also was a company associated with it, and it sparked an oil boom and rapid expansion of the global petroleum industry. The same year, engine-drilled wells appeared in West Virginia.
==== Member of the Order of the British Empire (MBE) ==== Civil Division Sotaga Paape. For services to education and the community. Filoimea Telito. For community and public services, especially to education.
7α-Acetylthio-17α-hydroxy-3-oxopregn-4-ene-21-carboxylic acid γ-lactone 7α-Acetylthio-3-oxo-17α-pregn-4-ene-21,17β-carbolactone 3-(3-Oxo-7α-acetylthio-17β-hydroxyandrost-4-en-17α-yl)propionic acid lactone 7α-Acetylthio-17α-(2-carboxyethyl)androst-4-en-17β-ol-3-one γ-lactone 7α-Acetylthio-17α-(2-carboxyethyl)testosterone γ-lactone
Postprandial somnolence (colloquially known as food coma or after-meal dip) is a benign state of drowsiness or lassitude following a meal, a general state of sleepiness and low energy related to activation of the parasympathetic nervous system in response to mass in the gastrointestinal tract. While there are numerous theories surrounding this behavior, such as decreased blood flow to the brain, neurohormonal modulation of sleep through digestive coupled signaling, or vagal stimulation, very few have been explicitly tested. To date, human studies have loosely examined the behavioral characteristics of postprandial sleep, demonstrating potential shifts in EEG spectra and self-reported sleepiness. To date, the only clear animal models for examining the genetic and neuronal basis for this behavior are the fruit fly, the mouse, and the nematode Caenorhabditis elegans.
Sources: en.wikipedia.org
It is a synthetic cyclic heptapeptide modelled on alpha-melanocyte-stimulating hormone. A lactam bridge links two side chains, forming a ring that stabilises the molecule against proteolysis. It belongs to the broader melanocortin peptide family.
No national medicines agency has approved melanotan-2 for clinical use. Afamelanotide, a related but distinct peptide, holds a marketing authorisation in the European Union for a rare photosensitivity disorder. Melanotan-2 itself is handled as a laboratory chemical.
Its broad activity across melanocortin receptors makes it a tool for probing pigmentation, appetite and vascular signalling. Early trials recorded skin darkening and other effects that were not the original focus of the work. Those observations generated hypotheses that later studies have examined.
Only a small number of early-stage human studies have been reported, and most were limited in size and duration. No large late-stage program has established a general efficacy or safety profile. The evidence base is therefore thin compared with approved medicines.