The short version of alpha-MSH analogue fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2025-12-01 and is reviewed periodically as new material appears.
The peptide was developed during the 1980s by researchers investigating melanocortin signalling and skin pigmentation pathways. Early work focused on analogues of alpha-melanocyte-stimulating hormone that would resist enzymatic breakdown more effectively than the parent molecule. Melanotan-2 emerged from that programme as a shortened, cyclised variant. Reports describing its synthesis and receptor activity later appeared in the scientific literature. Commercial availability grew through unregulated channels rather than through pharmaceutical approval.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Synthetic cyclic heptapeptide |
| Molecular mass | Approximately 1024 g/mol | Depends on counter-ion content |
| Appearance | White to off-white powder | Commonly supplied as a lyophilised solid |
| Solubility | Freely soluble in water | Also dissolves in common aqueous buffers |
| Typical storage | -20 degrees Celsius, desiccated | Protect from light and repeated freeze-thaw |
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.
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.
The permissible limits for ionizing radiation intensity are consistently being revised downward. The concept of radiation protection now includes regulations for the handling of non-ionizing radiation. In the Federal Republic of Germany, radiation protection regulations are developed and issued by the Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV). The Federal Office for Radiation Protection is involved in the technical work. In Switzerland, the Radiation Protection Division of the Federal Office of Public Health is responsible, and in Austria, the Ministry of Climate Action and Energy.
== Applications == There are five major areas where protein arrays are being applied: diagnostics, proteomics, protein functional analysis, antibody characterization, and treatment development. Diagnostics involves the detection of antigens and antibodies in blood samples; the profiling of sera to discover new disease biomarkers; the monitoring of disease states and responses to therapy in personalized medicine; the monitoring of environment and food. Digital bioassay is an example of using protein microarray for diagnostic purposes. In this technology, an array of microwells on a glass/polymer chip are seeded with magnetic beads (coated with fluorescent tagged antibodies), subjected to targeted antigens and then characterised by a microscope through counting fluorescing wells. A cost-effective fabrication platform (using OSTE polymers) for such microwell arrays has been recently demonstrated and the bio-assay model system has been successfully characterised. Proteomics pertains to protein expression profiling i.e. which proteins are expressed in the lysate of a particular cell. Protein functional analysis is the identification of protein–protein interactions (e.g. identification of members of a protein complex), protein–phospholipid interactions, small molecule targets, enzymatic substrates (particularly the substrates of kinases) and receptor ligands. Antibody characterization is characterizing cross-reactivity, specificity and mapping epitopes.
=== Name === Within the INN, USAN, BAN, and AAN naming systems this drug is known as butorphanol, while within JAN it is named torbugesic. As the tartrate salt, butorphanol is known as butorphanol tartrate (USAN, BAN).
=== 5α-Reductase inhibition === Progesterone is a substrate for 5α-reductase, and has been found to act as a competitive inhibitor of this enzyme in vitro in a variety of studies. In one study, it showed IC50Tooltip half-maximal inhibitory concentration values of 1,375 nM and 88 nM (in the presence of 50 nM androstenedione as the substrate) for 5α-reductase types 1 and 2, respectively. 5α-Reductase is highly expressed in skin, hair follicles, and prostate gland, and is responsible for the transformation of testosterone into the several-fold more potent androgen DHT in such tissues. As such, it has been suggested that progesterone might possess some antiandrogenic effect via acting as a 5α-reductase inhibitor. However, inhibition of 5α-reductase by progesterone is described as a weak effect that has only been demonstrated in vitro and at supraphysiological concentrations. In accordance, physiological levels of circulating progesterone have not been found to importantly influence circulating DHT concentrations. Congenital 5α-reductase 2 deficiency is a rare intersex condition which is associated with ambiguous genitalia in male fetuses due to a deficiency in DHT production during genital differentiation. Experimental prenatal exposure to established 5α-reductase inhibitors like finasteride has been found to produce similar feminized genital defects in male animals including rodents and monkeys. In contrast, exogenous administration of progesterone to pregnant rodents and monkeys has resulted in minimal abnormality in either male or female pups.
=== August === August 2 COVID-19 pandemic COVID-19 vaccination: Over 70% of adults are reported to have received at least one dose of a COVID-19 vaccine. U.S. Senator Lindsey Graham announces that he has tested positive for COVID-19, despite receiving the COVID-19 vaccine. August 3 COVID-19 vaccination: New York City mandates vaccines for indoor dining, gyms, and performances, becoming the first U.S. city to do so. A report released by New York Attorney General Letitia James says that Governor Andrew Cuomo sexually harassed 11 women. August 4 Magistrate Judge N. Reid Neureiter of Colorado announces that two lawyers, Gary D. Fielder and Ernest John Walker, will be sanctioned for filing a lawsuit challenging the results of the 2020 election. COVID-19 pandemic: Louisiana reports 2,247 hospitalizations, a new single-day record. August 5 – President Biden sets a goal for half of new cars sold to be zero-emission by 2030. August 6 COVID-19 pandemic COVID-19 vaccination: The CDC reports that 50% of the U.S. population (including both adults and children) is now fully vaccinated, or about 166 million people. Florida reports 22,783 new cases of COVID-19, a new single-day record. Aftermath of the January 6 United States Capitol attack: New Jersey gym owner Scott K. Fairlamb and Washington resident Devlyn D. Thompson pleads guilty to assaulting U.S. Capitol Police officers during the Capitol riot, becoming the first suspects to do so.
Sources: en.wikipedia.org
== Tethelin (Roberson's patent and trade-mark) == In March 1916, Robertson published a suite of five interconnected articles in the Journal of Biological Chemistry, describing the process through which a material, which he called tethelin (from τεθηλώς, 'growing'), he and his assistant, Louis Adolph Ray (1886-1960), had extracted (in 1915) from the anterior lobes of ox pituitaries acquired from a local slaughterhouse (BR.22), and its positive effects on the growth of his experimental mice (BR.23–BR.26). Robertson claimed that the substance was the pituitary's "growth-controlling principle"; and, according to Robertson's account, on-going research demonstrated that tethelin not only controlled growth, but was very effective in the treatment of ulcers of long standing and slow-healing wounds. Prior to the (March 1916) publication of his discoveries, Robertson had not only been granted the US patent (BR.18) and the UK patent (BR.19) for the "Tethelin" extraction process, but had also begun to use the trade-mark TETHELIN, the rights to which he was subsequently granted in December 1916 (BR.21). Well aware of Jokichi Takamine's earlier struggle to patent adrenalin, and the challenges and time delays Takamine experienced, Robertson simply patented his process, and not his product.
=== EC 1.2.7 With an iron–sulfur protein as acceptor === EC 1.2.7.1: pyruvate synthase EC 1.2.7.2: Now included with EC 1.2.7.1, pyruvate synthase. EC 1.2.7.3: 2-oxoglutarate synthase EC 1.2.7.4: anaerobic carbon monoxide dehydrogenase EC 1.2.7.5: aldehyde ferredoxin oxidoreductase EC 1.2.7.6: glyceraldehyde-3-phosphate dehydrogenase (ferredoxin) EC 1.2.7.7: 3-methyl-2-oxobutanoate dehydrogenase (ferredoxin) EC 1.2.7.8: indolepyruvate ferredoxin oxidoreductase EC 1.2.7.9: deleted, identical to EC 1.2.7.3, 2-oxoglutarate synthase EC 1.2.7.10: oxalate oxidoreductase EC 1.2.7.11: 2-oxoacid oxidoreductase (ferredoxin) EC 1.2.7.12: formylmethanofuran dehydrogenase
In dental anatomy, the apical foramen, literally translated "small opening of the apex," is the tooth's natural opening, found at the root's very tip—that is, the root apex — whereby an artery, vein, and nerve enter the tooth and commingle with the tooth's internal soft tissue, called pulp. Additionally, the apical foramen is the point where the pulp meets the periodontal tissues, the connective tissues that surround and support the tooth. The foramen is located 0.5mm to 1.5mm from the apex of the tooth. Each tooth has an apical foramen.
Their hypotheses were confirmed in the mid-1970s and 1980s by Erwin Neher and Bert Sakmann, who developed the technique of patch clamping to examine the conductance states of individual ion channels. In the 21st century, researchers are beginning to understand the structural basis for these conductance states and for the selectivity of channels for their species of ion, through the atomic-resolution crystal structures, fluorescence distance measurements and cryo-electron microscopy studies. Julius Bernstein was also the first to introduce the Nernst equation for resting potential across the membrane; this was generalized by David E. Goldman to the eponymous Goldman equation in 1943. The sodium–potassium pump was identified in 1957 and its properties gradually elucidated, culminating in the determination of its atomic-resolution structure by X-ray crystallography. The crystal structures of related ionic pumps have also been solved, giving a broader view of how these molecular machines work.
Sources: en.wikipedia.org
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.
It is shorter than the native hormone and carries a cyclic constraint that improves stability. These changes raise receptor potency and slow breakdown relative to the naturally occurring peptide.
Published accounts date its development to the 1980s, when researchers were generating analogues of melanocyte-stimulating hormone. That work aimed to produce more stable compounds for studying pigmentation biology.
The dry powder is more stable during transport and storage than a solution. It also allows a known amount of material to be reconstituted at a chosen concentration.