Everything below concerns alpha-MSH analogue. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-08-23. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Freeze-dried melanotan-2 is normally kept as a desiccated powder at minus twenty degrees Celsius or lower, shielded from light and moisture. Peptides of this size degrade through hydrolysis, oxidation and deamidation, and each pathway accelerates as temperature and water activity rise. Repeated freeze-thaw cycles promote aggregation and loss of material, so aliquoting a stock solution before freezing is standard laboratory practice. Once dissolved, the solution is markedly less stable than the powder. In laboratory work, solutions are generally refrigerated and used within days rather than kept for months.
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.
Structurally, Melanotan-2 retains the core recognition motif of alpha-melanocyte-stimulating hormone while adding a lactam bridge that links two side chains and constrains the molecule into a ring. This modification lowers susceptibility to enzymatic degradation. The compound acts as an agonist at melanocortin receptors, particularly subtypes associated with melanin production. Because the same receptor family influences several physiological processes, researchers note that its activity is not confined to pigmentation alone. Receptor selectivity continues to be examined in published studies.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its sequence incorporates modified residues that increase potency and extend biological activity relative to the native hormone. The compound binds receptors of the melanocortin family and is examined mainly in laboratory research. It does not occur naturally and exists only as a manufactured chemical entity produced by solid-phase synthesis.
| 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 |
Regulatory treatment varies by country. In the United States, melanotan-2 is not approved for any indication, and products marketed for human use fall outside the approved drug framework. Some other jurisdictions have placed it under prescription controls or listed it as a prohibited or restricted substance. Online listings frequently describe the material as a research chemical, a category that does not carry the same manufacturing and labelling requirements as approved medicines.
Solid peptide material is generally stable when kept cold and dry. Common practice is storage at -20 degrees Celsius or lower, with desiccant and protection from light. Repeated freeze-thaw cycles and exposure to moisture are associated with degradation, aggregation, or loss of material. Once dissolved, stability depends on solvent, concentration, and temperature, and solutions are usually treated as short-lived unless stability data support longer periods. Handling notes typically emphasise minimising time at ambient temperature.
Identity and purity are assessed with chromatographic and mass spectrometric techniques. Reversed-phase high-performance liquid chromatography separates the target peptide from related impurities and degradation products, and the resulting retention time is compared against a reference standard. Mass spectrometry, often coupled to liquid chromatography, confirms molecular mass. Amino acid analysis or peptide mapping can provide additional sequence-level confirmation when required. Results are only as reliable as the reference materials used alongside them.
Published pharmacokinetic information is limited and comes mainly from small studies rather than registrational trials. Plasma half-life is usually described as short, on the order of tens of minutes, followed by rapid tissue distribution and clearance of the intact peptide. Metabolites and low concentrations of parent compound have been reported in urine, a detail relevant to anti-doping and forensic testing. Whether repeated exposure changes receptor sensitivity or clearance over time remains an open question. Values differ noticeably between analytical assays, so published numbers should be read as approximate rather than definitive.
Melanotan II is a synthetic cyclic heptapeptide with the sequence Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, corresponding to a molecular formula of C50H69N15O9 and a monoisotopic mass near 1024 daltons. It was designed as a structural analogue of alpha-melanocyte-stimulating hormone, a peptide hormone produced by cleavage of proopiomelanocortin. A lactam bridge between the aspartate and lysine side chains closes the ring, and the C-terminal amide removes a free carboxyl group. Both modifications increase resistance to enzymatic degradation compared with the linear parent hormone. Four substitutions distinguish it from afamelanotide, the linear analogue studied under the name melanotan I.
Receptor-binding studies classify melanotan II as a non-selective melanocortin agonist. It interacts with MC1R, MC3R, MC4R and MC5R, with reported affinities in the low nanomolar range and no strong subtype preference. Activation of MC1R on dermal melanocytes shifts pigment synthesis toward eumelanin, the dark polymer deposited in melanosomes and transferred to keratinocytes. Because the same peptide engages MC4R in the hypothalamus, it also appears in animal work on food intake and erectile response, which is why it is discussed in both pigment and metabolic research. Which receptor populations dominate after systemic exposure in humans is not fully established.
A xerophile (from Ancient Greek ξηρός (xerós), meaning "dry", and φίλος (phílos), meaning "loving") is an extremophilic organism that can grow and reproduce in conditions with a low availability of water, also known as water activity. Xerophiles are "xerotolerant", meaning tolerant of dry conditions. They can often survive in environments with water activity below 0.8; above which is typical for most life on Earth. Typically xerotolerance is used with respect to matrix drying, where a substance has a low water concentration. These environments include arid desert soils. The term osmophile, or osmotolerant, is typically applied to microorganisms that can grow in solutions with high solute concentrations (salts, sugars), such as halophiles.
==== Genetically induced ==== Type 1 diabetes (T1D) is a multifactorial autoimmune disease with a strong genetic component. Although environmental factors also play a significant role, the genetic susceptibility to T1D is well established, with several genes and loci implicated in disease development. The most significant genetic contribution to T1D comes from the human leukocyte antigen (HLA) region on chromosome 6p21. The HLA class II genes, particularly HLA-DR and HLA-DQ, are the strongest genetic determinants of T1D risk. Specific combinations of alleles such as HLA-DR3-DQ2 and HLA-DR4-DQ8 have been associated with a higher risk of developing T1D. Individuals carrying both of these haplotypes (heterozygous DR3/DR4) are at an even greater risk. These HLA variants are thought to influence the immune system's ability to differentiate between self and non-self antigens, leading to the autoimmune destruction of pancreatic beta cells. Conversely, some HLA haplotypes, such as HLA-DR15-DQ6, are associated with protection against T1D, suggesting that variations in these immune-related genes can either predispose or protect against the disease. In addition to HLA, multiple non-HLA genes have been implicated in T1D susceptibility. Genome-wide association studies (GWAS) have identified over 50 loci associated with an increased risk of T1D. Some of the most notable genes include:
==== Measurement ==== In women, serum estradiol is measured in a clinical laboratory and reflects primarily the activity of the ovaries. The Estradiol blood test measures the amount of estradiol in the blood. It is used to check the function of the ovaries, placenta, adrenal glands. This can detect baseline estrogen in women with amenorrhea or menstrual dysfunction, and to detect the state of hypoestrogenicity and menopause. Furthermore, estrogen monitoring during fertility therapy assesses follicular growth and is useful in monitoring the treatment. Estrogen-producing tumors will demonstrate persistent high levels of estradiol and other estrogens. In precocious puberty, estradiol levels are inappropriately increased.
=== Benign prostatic hyperplasia === A meta-analysis found that tadalafil is an effective treatment for lower urinary tract symptoms due to benign prostatic hyperplasia and that such treatment had a low rate of adverse effects. Tadalafil is FDA-approved for males as a therapy to treat and prevent symptoms of benign prostatic hyperplasia, such as urinary urgency, hesitancy, weak stream, dribbling, and incontinence. Tadalafil was found to have similar benefits for lower urinary tract symptoms as the usually prescribed tamsulosin.
== Function == Dihydrokaempferol 4-reductase is part of the biosynthetic pathway to anthocyanidins and anthocyanins, which are common plant pigments. In addition to converting aromadendrin to leucopelargonidin, it converts ampelopsin ((+)-dihydromyricetin) to leucodelphinidin.
Sources: en.wikipedia.org
With the army unmobilised and the headquarters thus unprotected, on 22 December protesters stormed the building and Victor Stănculescu convinced the Romanian leader to flee with his wife via helicopter. Denounced afterward by Stănculescu, they suddenly found themselves as fugitives and thus seemingly guilty of accused crimes, and a manhunt was declared. Captured in Târgoviște, they were tried by a drumhead military tribunal on charges of genocide, damage to the national economy, and abuse of power to execute military actions against the Romanian people. They were convicted on all charges, sentenced to death, and immediately executed on Christmas Day 1989. They were the last people to be condemned to death and executed in Romania, as capital punishment was abolished soon after. For several days after Ceaușescu fled, many would be killed in the crossfire between civilians and armed forces personnel which believed the other to be Securitate 'terrorists'. Although news reports at the time and modern media often makes reference to the Securitate fighting against the revolution, there has never been any evidence supporting the claim of an organised effort. Hospitals in Bucharest were treating as many as thousands of civilians. Following an ultimatum, many Securitate members turned themselves in on 29 December with the assurance they would not be tried. Present-day Romania has unfolded in the shadow of the Ceaușescus along with its Communist past, and its tumultuous departure from it.
=== Open-chain form === An open-chain form of glucose makes up less than 0.02% of the glucose molecules in an aqueous solution at equilibrium. The rest is one of two cyclic hemiacetal forms. In its open-chain form, the glucose molecule has an open (as opposed to cyclic) unbranched backbone of six carbon atoms, where C-1 is part of an aldehyde group H(C=O)−. Therefore, glucose is also classified as an aldose, or an aldohexose. The aldehyde group makes glucose a reducing sugar giving a positive reaction with the Fehling test.
=== Intrauterine administration === A one-year progesterone intrauterine device (IUD) for hormonal birth control was previously available in the United States and a few other countries under the brand name Progestasert. It was marketed between 1976 and 2001. The IUD was never widely used due to a relatively high contraceptive failure rate of 2.9% and the requirement of annual replacement. It contained 38 mg progesterone and released 65 μg progesterone into the uterus per day (totaling up to about 35 mg after one year). For comparison, a woman's body produces on average about 25 mg progesterone per day during the luteal phase. While effective as a form of contraception and for decreasing menstrual bleeding and discomfort, long-lived IUDs can fundamentally only deliver small amounts of progesterone per day, and hence intrauterine progesterone cannot achieve adequate circulating progesterone levels and is unsuitable as a form of systemic therapy. Aside from progesterone, IUDs of progestins, such as levonorgestrel (Mirena/Levosert/Skyla), are available as well.
=== 7 August === Sudanese prosecutors charged Hemedti and 16 other TASIS leaders with committing war crimes in El Fasher and South Kordofan. Three SLM officials (Legal Advisor Mahmoud Koreina, Economic Affairs Advisor Adam al-Nur, and Media Advisor Mustafa al-Jamil) announced the formation of a splinter faction in Uganda following their dismissal by Minni Minawi. Eighteen people were killed in RSF attacks on the villages of Markaz Al-Ziyadia and Lamina al-Ziyadiyah in North Kordofan.
=== Wound healing === Vascularization is crucial for wound healing, as it provides oxygen and nutrients necessary for tissue repair. Angiogenesis temporarily increases vascular density around the wound, aiding the healing process. Vascular endothelial growth factor (VEGF) is a key pro-angiogenic factor in this process, stimulating both vasculogenesis and angiogenesis in the skin. Impaired angiogenesis can result in delayed wound healing, as seen in conditions such as diabetes, where chronic wounds often exhibit reduced levels of active VEGF. Therapeutic stimulation of angiogenesis is being explored to speed up healing, especially in persistent wounds.
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.
It is a synthetic cyclic heptapeptide and an analogue of alpha-melanocyte-stimulating hormone. The molecule is produced by chemical synthesis rather than extracted from a biological source.