If you have been reading about Alpha-MSH 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.
Updated 2026-01-08. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 |
|---|---|---|
| Regulatory status | Not approved as a medicine | No marketing authorization in major jurisdictions |
| Scheduling example | Prescription-only supply in some countries | Handled as an unlicensed medicine where restricted |
| Sports classification | Prohibited peptide | Appears on anti-doping prohibited lists |
| Reported presentation | Lyophilized vial | Nominal content varies between vendors |
| Detection approach | Liquid chromatography–tandem mass spectrometry | Used in anti-doping and forensic testing |
Independent verification is central to quality control because the compound is not produced under pharmaceutical manufacturing standards. Third-party laboratories can measure purity, identity, residual solvents, and microbial contamination, though the scope of testing varies between services. Reported analyses of vendor samples have shown batch-to-batch variation in peptide content and the presence of truncated or oxidized species. How much of this variation reflects synthesis conditions versus storage and shipping is not well characterized. No harmonized reference standard exists for the material as sold.
Handling guidance for melanotan II follows general practice for small synthetic peptides rather than a product-specific monograph. Lyophilized powder is typically kept at minus twenty degrees Celsius or colder, protected from light and moisture, because warmth and humidity accelerate degradation. Once reconstituted, solutions are usually refrigerated and used within a short window, as hydrolysis and microbial growth both become concerns. Repeated freeze-thaw cycles are generally avoided. These conventions come from laboratory peptide chemistry and not from formal stability studies on this specific compound.
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.
Regulatory status differs by country, and in many places supplying the compound for human consumption is unlawful. Vendors frequently label material as intended for research use only, a designation that shifts stated purpose but does not create a legal pathway for personal use. Certificates of analysis accompanying such products vary widely in detail and provenance. Third-party testing exists but is voluntary, and results are rarely linked to a specific lot in a publicly verifiable way.
Identity testing for a synthetic peptide relies on several complementary methods. Reversed-phase high-performance liquid chromatography separates the target from related impurities and reports purity as a percentage of total peak area. Mass spectrometry confirms molecular mass and can reveal deletions or truncations. Amino acid analysis and peptide mapping provide sequence-level confirmation, while counter-ion content and residual solvents are measured separately. A purity figure alone does not establish identity, so a complete dataset combines chromatographic and spectrometric evidence.
Lyophilized peptide powder is generally stored frozen, protected from light and moisture. Tryptophan residues are susceptible to oxidation, and the lactam bridge can hydrolyze under strongly acidic or basic conditions. Solutions prepared for laboratory work degrade faster than dry powder, and repeated freeze-thaw cycles accelerate loss. Common practice is to aliquot solutions before freezing and to avoid alkaline buffers. Reported stability windows vary with concentration, buffer, and temperature, so exact shelf lives are method-specific rather than universal.
=== Efforts to reduce recreational use in the US === In 2011, the Obama administration released a white paper describing the administration's plan to deal with the opioid crisis. The administration's concerns about addiction and accidental overdosing have been echoed by numerous other medical and government advisory groups around the world. As of 2015, prescription drug monitoring programs exist in every state except for Missouri. These programs allow pharmacists and prescribers to access patients' prescription histories in order to identify suspicious use. However, a survey of US physicians published in 2015 found that only 53% of doctors used these programs, while 22% were not aware that the programs were available to them. The Centers for Disease Control and Prevention (CDC) was tasked with establishing and publishing a new guideline, and was heavily lobbied. In 2016, the CDC published its Guideline for Prescribing Opioids for Chronic Pain, recommending that opioids only be used when benefits for pain and function are expected to outweigh risks, and then used at the lowest effective dosage, with avoidance of concurrent opioid and benzodiazepine use whenever possible. Research suggests that the prescription of high doses of opioids related to chronic opioid therapy (COT) can at times be prevented through state legislative guidelines and efforts by health plans that devote resources and establish shared expectations for reducing higher doses. On 10 August 2017, Donald Trump declared the opioid crisis a (non-FEMA) national public health emergency.
This is by inhibiting the norepinephrine transporter (NET) and preventing entry of tyramine into presynaptic noradrenergic neurons where tyramine induces the release of norepinephrine. As a result, NRIs may reduce the risk of tyramine-related hypertensive crisis in people taking MAOIs. Norepinephrine–dopamine reuptake inhibitors (NDRIs), like methylphenidate and bupropion, are also considered to be safe in combination with MAOIs. However, initiation at low doses and slow upward dose titration is advisable in the case of both NRIs and NDRIs due to possible potentiation of their effects and side effects by MAOIs. Selegiline may potentiate the effects of serotonergic psychedelics that are MAO-B substrates, such as 2C drugs like 2C-B, 2C-I, and 2C-E.
24 January The discovery of 85 exoplanet candidates based on data from the TESS observatory is reported. All have orbital periods of between 20 and 700 days, with temperatures similar to those of Solar System planets. A global analysis of groundwater levels reports rapid declines of over 0.5 meters per year are widespread and that declines have accelerated over the past four decades in 30% of the world's regional aquifers. The study also shows cases in which depletion trends have reversed following interventions such as policy changes. 25 January – The Laser Interferometer Space Antenna (LISA) is given the go-ahead by the European Space Agency (ESA). It will launch in 2035. 26 January – Astronomers report the detection of water vapor in the atmosphere of GJ 9827 d, an exoplanet about twice the size of Earth. 29 January Elon Musk's startup Neuralink implants their first microchip into a human brain. A robotic sensor able to read braille with 87.5% accuracy and at twice the speed of a human is demonstrated. 31 January – NASA reports the discovery of a super-Earth called TOI-715 b, located in the habitable zone of a red dwarf star about 137 light-years away. Promising innovations relating to global challenges are reported: a self-powered solar panel cleaning system using an electrodynamic screen, removing contaminants through high-voltage electric fields, is demonstrated (4 Jan), an atmospheric water generator (WaterCube) for humidity levels above 40% is released (9 Jan).
== Preparation == Bark is collected during Qingming (Pure Brightness), the fifth solar term (April 4–20). It is sun-dried and cut into slices. The bark may be used raw or fried with salt. Typical dosage is 3–10 grams. A variety of methods of water and ethanol extraction may have differing activities (see below) and methods such as "semi-bionic extraction" have been investigated to improve yields. Some pharmacological activities of the bark can be standardized by analyzing the level of berberine using a monoclonal antibody, thin-layer chromatography, HPLC, potentiometry, or acidic potassium permanganate chemiluminescence. There are quantitative differences between the two species of Cortex Phellodendri (P. amurense and chinense) and it has been suggested that they should be used as separate resources in the clinic. An analysis of 31 commercial samples in 1993 found that the total level of five alkaloids in samples of P. wilsonii and P. amurense var. sachalinense was 4.1% (mostly berberine), while the level in P. amurense and Ph. chinense was 1.5%. The levels of four harmful trace heavy metals (arsenic, cadmium, mercury, and thallium) in P. chinense for export are limited by the Pharmacopoeia of the People's Republic of China and the Green Trade Standard for Importing and Exporting Medicinal Plant and Preparation.
Hydrogen bonds arise from a combination of electrostatics (multipole-multipole and multipole-induced multipole interactions), covalency (charge transfer by orbital overlap), and dispersion (London forces). In weaker hydrogen bonds, hydrogen atoms tend to bond to elements such as sulfur (S) or chlorine (Cl); even carbon (C) can serve as a donor, particularly when the carbon or one of its neighbors is electronegative (e.g., in chloroform, aldehydes and terminal acetylenes). Gradually, it was recognized that there are many examples of weaker hydrogen bonding involving donor other than N, O, or F and/or acceptor Ac with electronegativity approaching that of hydrogen (rather than being much more electronegative). Although weak (about 4.2 kJ/mol (1 kcal/mol)), "non-traditional" hydrogen bonding interactions are ubiquitous and influence structures of many kinds of materials. The definition of hydrogen bonding has gradually broadened over time to include these weaker attractive interactions. In 2011, an IUPAC Task Group recommended a modern evidence-based definition of hydrogen bonding, which was published in the IUPAC journal Pure and Applied Chemistry. This definition specifies:
Sources: en.wikipedia.org
Delta sleep-inducing peptide, as the name suggests, induces delta wave EEG activity. Alcohol reduces SWS delta wave activity, thereby restricting the release of growth hormone (GH) by the pituitary. The muramyl peptide, muramyl dipeptide (MDP, N-acetylmuramyl-L-alanyl-D-isoglutamine) has been shown to increase delta wave activity during slow wave sleep. The drug gabapentin, a drug used to control epileptic seizures, increases delta-wave activity and slow wave sleep in adults. While hypnotics like zolpidem increase slow wave sleep, they do not increase delta wave activity, and instead increase spindle activity during slow wave sleep. Gamma-hydroxy butyrate (GHB) increases delta slow-wave sleep as well as sleep-related growth hormone (GH). Administration of high-dose nitrous oxide is associated with transient, large amplitude slow-delta oscillations.
== Notes == ^ α: GLA-domainless protein C is produced by selective proteolysis between residues 82 and 83 to remove the N-terminal portion of the protein that includes essentially all of the GLA domain (residues 47–88). The N-terminus was removed in order to make crystallization of the protein easier. ^ β: In hypereosinophilia, excess eosinophil-specific granule proteins (such as major basic protein, erythropoietin and eosinophil cationic protein) on the endothelial surface bind to thrombomodulin and inhibit its participation in the activation of protein C by electrostatic interaction on the surface of thrombomodulin.
Overnutrition caused by overeating is also a form of malnutrition. In the United States, more than half of all adults are now overweight—a condition that, like hunger, increases susceptibility to disease and disability, reduces worker productivity, and lowers life expectancy. Overeating is much more common in the United States, since most people have adequate access to food. Many parts of the world have access to a surplus of non-nutritious food. Increased sedentary lifestyles also contribute to overnutrition. Yale University psychologist Kelly Brownell calls this a "toxic food environment", where fat- and sugar-laden foods have taken precedence over healthy nutritious foods. In these developed countries, overnutrition can be prevented by choosing the right kind of food. More fast food is consumed per capita in the United States than in any other country. This mass consumption of fast food results from its affordability and accessibility. Fast food, which is low in cost and nutrition, is high in calories. Due to increasing urbanization and automation, people are living more sedentary lifestyles. These factors combine to make weight gain difficult to avoid. Overnutrition also occurs in developing countries. It has appeared in parts of developing countries where income is on the rise. It is also a problem in countries where hunger and poverty persist. Economic development, rapid urbanisation and shifting dietary patterns have increased the burden of overnutrition in the cities of low and middle-income countries.
Chocolate agar (CHOC) or chocolate blood agar (CBA) is a nonselective, enriched growth medium used for isolation of pathogenic bacteria. It is a variant of the blood agar plate, containing red blood cells that have been lysed by slowly heating to 80 °C. Chocolate agar is used for growing fastidious respiratory bacteria, such as Haemophilus influenzae and Neisseria meningitidis. In addition, some of these bacteria, most notably H. influenzae, need growth factors such as nicotinamide adenine dinucleotide (factor V or NAD) and hemin (factor X), which are inside red blood cells; thus, a prerequisite to growth for these bacteria is the presence of red blood cell lysates. The heat also inactivates enzymes which could otherwise degrade NAD. The agar is named for its color and contains no chocolate products.
Colistin, also known as polymyxin E, is an antibiotic medication used as a last-resort treatment for multidrug-resistant Gram-negative infections including pneumonia. These may involve bacteria such as Pseudomonas aeruginosa, carbapenem-resistant Klebsiella pneumoniae (CRKP), or Acinetobacter. It comes in two forms: colistimethate sodium can be injected into a vein, injected into a muscle, or inhaled, and colistin sulfate is mainly applied to the skin or taken by mouth. Colistimethate sodium is a prodrug; it is produced by the reaction of colistin with formaldehyde and sodium bisulfite, which leads to the addition of a sulfomethyl group to the primary amines of colistin. Colistimethate sodium is less toxic than colistin when administered parenterally. In aqueous solutions, it undergoes hydrolysis to form a complex mixture of partially sulfomethylated derivatives, as well as colistin. Resistance to colistin began to appear as of 2015. Common side effects of the injectable form include kidney problems and neurological problems. Other serious side effects may include anaphylaxis, muscle weakness, and Clostridioides difficile-associated diarrhea. The inhaled form may result in constriction of the bronchioles. It is unclear if use during pregnancy is safe for the fetus. Colistin is in the polymyxin class of medications. It works by breaking down the cytoplasmic membrane, which generally results in bacterial cell death. Colistin was discovered in 1947 and colistimethate sodium was approved for medical use in the United States in 1970.
Sources: en.wikipedia.org
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.
The peptide is listed as prohibited in competitive sport, so laboratories develop detection methods and monitor for its presence. Its appearance in enforcement reports reflects that classification rather than any approved athletic use. Analytical work in this area focuses on identifying the molecule and its breakdown products in biological samples.
Chromatographic separation combined with mass spectrometry identifies the peptide and estimates its amount in a sample. Testing can confirm whether the expected molecule is present and at what concentration. It cannot establish how a product was manufactured or whether it meets any purity standard.
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.