The short version of afamelanotide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-11-28 and is reviewed periodically as new material appears.
Verification of a purchased sample requires documentation linking a batch to a certificate of analysis, and that document should be read for the methods used rather than the headline purity figure. A single chromatographic percentage does not establish identity. Independent laboratories can perform identity and content assays, but no such test establishes that a product is suitable for human use. Claims about efficacy rest largely on small, early studies rather than on replicated controlled trials, and that gap remains open.
Identity testing for a cyclic peptide of this size usually relies on reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The mass spectrum confirms molecular weight, while the chromatographic trace indicates the proportion of related impurities. Tandem mass spectrometry can provide sequence-level information when fragmentation data are compared against a reference standard. Nuclear magnetic resonance is sometimes used to confirm the lactam bridge, although it requires more material and greater operator expertise than routine chromatographic methods.
The compound emerged from research programs in the 1980s that examined analogues of alpha-melanocyte-stimulating hormone for pigmentation and photoprotection. Investigators modified the native sequence to extend activity duration and potency. A related analogue, afamelanotide, was developed within the same broad line of inquiry and eventually gained approval in certain jurisdictions for a rare light-sensitivity condition. Melanotan-2 itself did not progress through the same regulatory route and has no approved therapeutic indication.
Melanocortin receptors comprise five subtypes with distinct tissue distributions and functions. Melanotan-2 is described in the literature as a non-selective agonist that engages several of these subtypes, including MC1R, MC3R, MC4R, and MC5R. MC1R is the subtype most directly linked to melanin production in skin cells. Because the compound is not subtype-selective, its observed effects in experimental settings are generally attributed to activity across multiple receptor pathways rather than to a single target.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white solid | Lyophilised cake or flake |
| Solubility class | Soluble in water and aqueous buffer | Also soluble in some polar organic solvents |
| Typical storage temperature | Minus 20 degrees Celsius or below | Desiccated and protected from light |
| Typical analytical method | LC-MS/MS | Reversed-phase separation with mass detection |
| Molecular formula | C50H69N15O9 | Free base; salt forms differ |
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.
Analytical confirmation of identity relies on mass spectrometry, most often coupled to liquid chromatography. Reversed-phase high-performance liquid chromatography separates the peptide from related impurities and provides a purity estimate based on peak area. Electrospray ionization mass spectrometry then confirms the expected molecular mass, while tandem mass spectrometry can map the fragment sequence. For research-grade material, these two techniques together form the standard minimum. Purity figures reported by vendors are frequently not traceable to an independent laboratory.
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.
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.
Regulatory status varies by jurisdiction, and the substance is frequently described as unapproved for therapeutic use. Some authorities classify it alongside prescription-only medicines or controlled categories, while others address it through general consumer protection rules. Analytical surveys have reported mismatches between label claims and measured content in products sold online, although the scope of such testing is limited. Whether these discrepancies are widespread remains an open question. Discussion in the literature therefore tends to combine chemistry, supply-chain observation and policy analysis.
The material is commonly handled as a lyophilized powder in sealed vials. The solid dissolves readily in water and in polar organic solvents, producing a clear solution after reconstitution. Light, heat and repeated freeze-thaw cycles are the concerns most often raised in handling guidance, because peptide bonds and the constrained ring can degrade. Working solutions are generally prepared fresh, and material left in solution is treated as less stable than the dry form. These properties shape how laboratories store and aliquot reference material.
Identity and purity are assessed mainly by reversed-phase high-performance liquid chromatography with ultraviolet detection, often paired with mass spectrometry. Retention time supports identity, while the mass spectrum confirms the molecular weight of the intact peptide. Purity is frequently reported as a percentage of total peak area, a figure that depends on the wavelength, column and gradient used. Impurity profiling may also look for truncated sequences, oxidised forms and residual counterions. Amino acid analysis and peptide mapping provide orthogonal confirmation when required.
Melanocytes are the pigment-producing cells of the skin, and they carry melanocortin-1 receptors on their surface. When the receptor is activated, cyclic adenosine monophosphate rises inside the cell and raises the activity of enzymes such as tyrosinase, which increases melanin output. Melanotan-2 binds melanocortin-1 receptors in vitro and in animal models, and this binding is generally described as the basis for the tanning effect. Other receptors account for different effects: melanocortin-4 receptors contribute to appetite and erectile signalling, while melanocortin-3 and melanocortin-5 receptors contribute to energy balance and exocrine function.
Early published reports described melanotan-2 as a tanning agent without sun protection, which means darkening is not the same as protection against ultraviolet radiation. Later studies explored the peptide in erectile dysfunction, hemorrhagic shock, and some skin conditions. No regulator in the United States or Europe has approved it for clinical use. Many products labelled melanotan-2 are sold without approval and their identity and purity are unverified. Its long-term safety in humans remains an open question.
The Archbishop of Canterbury, Justin Welby, announces his resignation following a review of his handling of historical allegations of abuse in the church by the barrister John Smyth QC. The NHS is to start offering Varenicline, a daily pill to help people stop smoking. A man is arrested in Westminster after reports of someone carrying a knife outside the Houses of Parliament. Samantha Harvey wins the Booker Prize for her novel Orbital. 13 November The Guardian announces that all 80 of its accounts on social media platform X (formerly Twitter) will stop posting content, due to the social media site's role in spreading far-right conspiracy theories and racism. DIY retailer Homebase collapses into administration, threatening 2,000 jobs. Statistics have revealed that a 26-year-old man from Wales is one of around 50 motorists still allowed to drive, despite exceeding the 30 penalty point limit, having accrued 229 penalty points. Health Secretary Wes Streeting orders a review into the potential cost to the NHS of implementing changes to the law regarding assisted dying. Streeting unveils plans for hospital league tables, and for the managers of failing hospitals to be sacked. 14 November Chancellor Rachel Reeves is reported to be planning the "biggest pension reform in decades" by merging council pension schemes into "pension megafunds" hoping they will boost economic growth. Three women who were employees of Harrods allege that they were sexually abused by Mohamed Al-Fayed's brother, Salah between 1989 and 1997.
== Spontaneous == Apoptotic DNA fragmentation is a natural fragmentation that cells perform in apoptosis (programmed cell death). DNA fragmentation is a biochemical hallmark of apoptosis. In dying cells, DNA is cleaved by an endonuclease that fragments the chromatin into nucleosomal units, which are multiples of about 180-bp oligomers and appear as a DNA ladder when run on an agarose gel. The enzyme responsible for apoptotic DNA fragmentation is the Caspase-activated DNase. CAD is normally inhibited by another protein, the Inhibitor of Caspase Activated DNase (ICAD). During apoptosis, the apoptotic effector caspase, caspase 3, cleaves ICAD and thus causes CAD to become activated.
=== Occupational harm reduction strategies === Drug and alcohol impairment while at work increases the risk of work-place accidents and decreases productivity. Employers such as the commercial driving and airline industry may conduct random drug tests on employees with the goal of deterring use to improve safety. There is some evidence that increasing the use of random drug testing in the airline industry reduces the percentage of people who test positive, however, it is unclear if this decrease is associated with a corresponding decrease in fatal or non-fatal injuries, other accidents, number of days absent from work. It is also not clear if there are other unwanted side effects that may result from random drug and alcohol testing in the workplace.
=== Influences === β-TG levels may increase with age. It is elevated in diabetes mellitus. β-TG levels have been found to be increased by treatment with the synthetic estrogen ethinylestradiol, though were not significantly increased by the natural estrogen estradiol valerate. Levels of β-TG have also been found to be increased or unchanged during normal pregnancy.
Sources: en.wikipedia.org
Plant breeding started with sedentary agriculture and particularly the domestication of the first agricultural plants, a practice which is estimated to date back 9,000 to 11,000 years. Initially early farmers simply selected food plants with particular desirable characteristics, and employed these as progenitors for subsequent generations, resulting in an accumulation of valuable traits over time. Grafting technology had been practiced in China before 2000 BCE. By 500 BCE grafting was well established and practiced. Gregor Mendel (1822–84) is considered the "father of genetics". His experiments with plant hybridization led to his establishing laws of inheritance. Genetics stimulated research to improve crop production through plant breeding. Selective breeding played a crucial role in the Green Revolution of the 20th century. Modern plant breeding is applied genetics, but its scientific basis is broader, covering molecular biology, cytology, systematics, physiology, pathology, entomology, chemistry, and statistics (biometrics). It has also developed its own technology.
Rubidium-87 has such a long half-life as to be essentially stable (longer than the age of the Earth). Rubidium-86 quickly decays to stable strontium-86 if produced either directly via (n,2n) reactions in rubidium-87, or via neutron capture in rubidium-85.
As researchers, usually with little time, usually conduct these tasks themselves and manually and the, largely cosmetic, unstandardized changes are required before, not after, the paper is accepted for publication, the study proposes journals start allowing "free-format submissions". A study (25 May) highlights a list of problematic persuasive methods in academic articles, such as exaggerating the importance of the work or insufficient contextualization by "Not citing previous work that decreases the perceived novelty of the current work".
Sources: en.wikipedia.org
In 1882, he was appointed professor of chemistry at the University of Erlangen and in 1885 at the University of Würzburg. In 1892, he succeeded von Hofmann as professor of chemistry at the Friedrich Wilhelm University of Berlin.
==== Preventive measures ==== In August 2010, Purdue Pharma reformulated their long-acting oxycodone line, marketed as OxyContin, using a polymer, Intac, to make the pills more difficult to crush or dissolve in water to reduce non-medical use of OxyContin. Inactive ingredients/excipients are butylated hydroxytoluene (BHT), hypromellose, polyethylene glycol 400, polyethylene oxide, magnesium stearate, and titanium dioxide. The FDA approved relabeling the reformulated version as abuse-resistant in April 2013. Pfizer manufactures a preparation of short-acting oxycodone, marketed as Oxecta, which contains inactive ingredients, referred to as tamper-resistant Aversion Technology. Approved by the FDA in the U.S. in June 2011, the new formulation, while not being able to deter oral recreational use, makes crushing, chewing, snorting, or injecting the opioid impractical because of a change in its chemical properties.
=== Myanmar === Myanmar, which has experienced civil war since 2021, has restricted private vehicle use to alternate days, and there are long queues at petrol stations. The country is lacking in refineries, and it relies on oil products imported from Thailand, Vietnam, and Singapore.
With a decreasing number of mothers who breast-feed, more infants become obese children as they grow up and are reared on infant formula instead. Fewer children go outside and engage in active play as technology, such as television and video games, keeps children indoors. Rather than walking or biking to a bus-stop or directly to school, more school-age children are driven to school by their parents, reducing physical activity. As family sizes decrease, the children's pester power, their ability to force adults to do what they want, increases. This ability enables them to have easier access to calorie-packed foods, such as candy and soda drinks. The social context around family meal-time plays a role in rates of childhood obesity.
Sources: en.wikipedia.org
Mass spectrometry combined with liquid chromatography provides both molecular weight confirmation and a measure of related impurities. Tandem mass spectrometry adds sequence information. A purity percentage reported without a mass measurement does not confirm what the material is.
No. Lyophilisation slows degradation rather than stopping it, and the rate depends on residual moisture, temperature and light exposure. Freezer storage extends useful life but does not make the material permanent.
A certificate is only as good as its traceability to a specific batch and a named laboratory. Documents lacking batch numbers, method descriptions or laboratory identifiers carry little weight. Confirming what was actually received generally requires a separate test of the material in hand.
No. Melanotan-2 is manufactured synthetically. The naturally occurring peptide in the same family is alpha-melanocyte-stimulating hormone, which the body produces as part of normal endocrine and neural signalling.