alpha-MSH analogue comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-10-02. Numbers and descriptions here follow the published literature rather than marketing material.
Melanotan-2 is a synthetic cyclic heptapeptide designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous tridecapeptide that regulates pigment production. Two modifications distinguish it from the natural hormone: norleucine replaces methionine at the N-terminus, which limits oxidation, and a D-phenylalanine substitution raises receptor affinity. The ring is closed through an aspartate-lysine lactam bridge, giving the molecule a constrained conformation. The free base has a molecular mass near 1024 daltons, and commercial material is usually supplied as an acetate salt. It appears in the literature as a research peptide rather than an approved therapeutic agent.
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.
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.
Solid peptide kept dry at minus twenty degrees Celsius, shielded from light and moisture, is generally considered stable for extended periods. Solutions are divided into single-use aliquots and held at minus twenty or minus eighty degrees Celsius, because repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. Hydrolysis of the backbone and oxidation of tryptophan are the principal degradation routes in aqueous solution, and both accelerate at ambient temperature. Hygroscopic uptake after a vial is opened can also shift the actual mass weighed, which affects any concentration calculated from it.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Free base; salt forms add to total mass |
| Molecular mass | About 1024 daltons | Calculated for the free base |
| Structural class | Cyclic heptapeptide | Contains D-phenylalanine and norleucine |
| Parent hormone | Alpha-melanocyte-stimulating hormone | Endogenous tridecapeptide of 13 residues |
| Receptor profile | Non-selective melanocortin agonist | Interacts with MC1R, MC3R, MC4R and MC5R |
Melanotan II is a synthetic cyclic heptapeptide analog derived from the core sequence of alpha-melanocyte-stimulating hormone. Researchers at the University of Arizona synthesized it during the 1980s while studying pigmentation and appetite signaling. The compound is not an approved medicine in any major jurisdiction and appears mainly in laboratory and research-chemical settings. Its structure incorporates a lactam bridge between side chains, which constrains the ring and slows enzymatic breakdown relative to the natural hormone.
Melanotan II binds several melanocortin receptor subtypes rather than a single target. MC1R on melanocytes drives melanin synthesis, while MC3R and MC4R participate in energy balance, appetite, and sexual response pathways. This lack of selectivity explains why reported effects extend beyond skin darkening. Substitutions at positions four and seven, including norleucine and D-phenylalanine, increase potency and resistance to peptidases. Understanding which receptor mediates which effect remains an active area of investigation.
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.
Melanotan-2, also written Melanotan II, is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence is Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, and the lactam bridge between the aspartate and lysine side chains constrains the peptide into a ring. This structural change increases receptor affinity and metabolic stability relative to the native hormone. The compound was created in the 1980s as a research tool for studying pigmentation biology.
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.
A qullqa (Quechua pronunciation: [ˈqʊʎˌqa] "deposit, storehouse"; (spelling variants: colca, collca, qolca, qollca) was a storage building found along roads and near the cities and political centers of the Inca Empire. These were large stone buildings with roofs thatched with "ichu" grass, or what is known as Peruvian feathergrass (Jarava ichu). To a "prodigious [extent] unprecedented in the annals of world prehistory" the Incas stored food and other commodities which could be distributed to their armies, officials, conscripted laborers, and, in times of need, to the populace. The uncertainty of agriculture at the high altitudes which comprised most of the Inca Empire was among the factors which probably stimulated the construction of large numbers of qullqas.
=== Physical Activity/Exercise === Along with diet, physical activity is also important for the management of diabetes. Not only does exercising regularly help manage blood sugar levels and weight, it helps reduce the risk of heart attack and stroke, reduces cholesterol and blood pressure levels, reduces risk of diabetes related complications, increases the effect of insulin, provides a boost in energy levels, helps reduce stress, and contributes to positive self-esteem. By exercising, the body becomes more sensitive to insulin, allowing for better absorption of glucose by the muscle cells, for up to 24 hours after exercise. In addition, studies have shown that physical activity, even below recommended amounts, has the ability to reduce risk of diabetic-related complications. In people with type 2 diabetes, the combination of aerobic ("cardio") exercise and strength training is effective. Aerobic exercise has been shown to largely improve HbA1c, and contributes to weight loss and the enhanced regulation of cholesterol and lipoproteins. This may be any form of continuous exercise that elevates breathing and heart rate, such as walking, swimming, or dancing. During the last 20 years, resistance training has gained recognition as an effective form of exercise for people with type 2 diabetes. A light walk after a meal (postprandial walking) is also recognized as effective in reducing postprandial glucose spikes in people with or at risk for type 2 diabetes. In youths with type 1 diabetes, there is an association between exercise and lower HBA1c.
Actin remodeling is the biochemical process that allows for the dynamic alterations of cellular organization. The remodeling of actin filaments occurs in a cyclic pattern on cell surfaces and exists as a fundamental aspect to cellular life. During the remodeling process, actin monomers polymerize in response to signaling cascades that stem from environmental cues. The cell's signaling pathways cause actin to affect intracellular organization of the cytoskeleton and often consequently, the cell membrane. Again triggered by environmental conditions, actin filaments break back down into monomers and the cycle is completed. Actin-binding proteins (ABPs) aid in the transformation of actin filaments throughout the actin remodeling process. These proteins account for the diverse structure and changes in shape of Eukaryotic cells. Despite its complexity, actin remodeling may result in complete cytoskeletal reorganization in under a minute.
Sources: en.wikipedia.org
Rotary vane pump, the most common Diaphragm pump, zero oil contamination Liquid ring high resistance to dust Piston pump, fluctuating vacuum Scroll pump, highest speed dry pump Screw pump (10 Pa) Wankel pump External vane pump Roots blower, also called a booster pump, has highest pumping speeds but low compression ratio Multistage Roots pump that combine several stages providing high pumping speed with better compression ratio Toepler pump Lobe pump The base pressure of a rubber- and plastic-sealed piston pump system is typically 1 to 50 kPa, while a scroll pump might reach 10 Pa (when new) and a rotary vane oil pump with a clean and empty metallic chamber can easily achieve 0.1 Pa. A positive displacement vacuum pump moves the same volume of gas with each cycle, so its pumping speed is constant unless it is overcome by backstreaming.
===== MeSH D08.811.682.667 – oxidoreductases acting on sulfur group donors ===== MeSH D08.811.682.667.061 – dihydrolipoamide dehydrogenase MeSH D08.811.682.667.076 – ferredoxin-nadp reductase MeSH D08.811.682.667.092 – glutathione reductase MeSH D08.811.682.667.124 – hydrogensulfite reductase MeSH D08.811.682.667.186 – protein-disulfide reductase (glutathione) MeSH D08.811.682.667.217 – sulfite dehydrogenase MeSH D08.811.682.667.249 – sulfite oxidase MeSH D08.811.682.667.374 – sulfite reductase (ferredoxin) MeSH D08.811.682.667.500 – sulfite reductase (nadph) MeSH D08.811.682.667.750 – thioredoxin reductase (nadph)
== Partnerships == Towards fulfilling its mandate, RCB is collaborating with various national and international institutions of repute. The partnerships are meant for exchange of ideas, information sharing, training, networking, conducting scientific colloquia, workshops, academic exchange programmes and student study visits within (and outside) India and for students of the Asia-Pacific region. RCB and National Institute of Advanced Industrial Science and Technology (AIST), Japan announced a partnership to further capacity building initiatives in bio-imaging and biotechnology. The agreement offers an excellent opportunity for both the institutions in capacity building, training and research collaborations, benefitting young scientists not only in India and Japan, but also from the UNESCO member countries in the Asia-Pacific and SAARC regions. In its continuing effort to fulfill the core mandate, RCB is actively engaged in a range of research and related activities in partnership with other academic institutions, which form part of the NCR Biotech Science Cluster, Faridabad. Shared facilities such as Advanced Technology Platform Centre (ATPC), and Bioincubators (supported by Biotechnology Industry Research Assistance Council (BIRAC)), which is meant to support the budding biotechnology entrepreneurs, are being established.
Sources: en.wikipedia.org
No regulatory agency has authorised melanotan-2 as a medicine for any indication. It circulates mainly as a research chemical or through unregulated channels. As a result, identity, purity and content are not independently guaranteed.
Melanotan-1, also called afamelanotide, is a linear analogue with greater selectivity for MC1R and has received approval in some jurisdictions for a specific photosensitivity disorder. Melanotan-2 is cyclic, less selective, and reaches central receptors more readily. The two are often confused in online discussion despite different pharmacology and regulatory status.
Alpha-MSH is an endogenous tridecapeptide derived from pro-opiomelanocortin. Melanotan-2 reproduces its core receptor-binding sequence inside a shortened, stabilised ring. The result is a molecule with a longer effective half-life and higher potency than the parent hormone.
Purity is normally stated as an area percentage from high-performance liquid chromatography, for example ninety-five or ninety-eight percent. That figure describes the proportion of ultraviolet-absorbing material eluting as the main peak. It says nothing about water content, counterions, residual solvents or mass fraction of the peptide itself.