A practical reference on alpha-MSH analog: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-06-30 and is reviewed periodically as new material appears.
Activity is attributed to agonism at melanocortin receptors, particularly MC1R and MC4R. Activation of MC1R on melanocytes increases melanin synthesis, which underlies the reported tanning effect. MC4R engagement in the central nervous system is linked to appetite suppression and to effects on sexual arousal reported in early clinical studies. Those studies were small and were not designed to establish efficacy or long-term safety. Receptor selectivity among the melanocortin subtypes is not absolute, which complicates attribution of any effect to a single pathway.
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 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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Analogue of alpha-melanocyte-stimulating hormone |
| Common synonyms | MT-II; melanotan 2 | No internationally accepted non-proprietary name |
| Typical presentation | Lyophilised powder in a sealed vial | Often supplied alongside a separate diluent |
| Regulatory status | Unapproved therapeutic substance | Customs seizure reported in several jurisdictions |
| Reported route in use | Subcutaneous injection | Self-administered outside clinical settings |
Melanotan-2 is a synthetic peptide designed as an analog of alpha-melanocyte-stimulating hormone, a signaling molecule produced in the pituitary and skin. Its structure is a linear chain of seven amino acids that folds into a ring through an internal lactam bridge joining two side chains. The compound is sometimes written as MT-II or MEL-2 in informal and commercial contexts. It belongs to the melanocortin peptide family, a group of short signaling molecules that share a conserved core sequence recognized by melanocortin receptors.
Two structural changes distinguish the synthetic peptide from the natural hormone. A norleucine residue replaces methionine at one position, and a D-configured phenylalanine replaces the natural L-form at another. Both substitutions slow enzymatic breakdown, which extends the molecule's persistence relative to the parent hormone. The lactam bridge further constrains the backbone into a stable conformation. These features are standard design strategies in peptide chemistry and are not unique to this compound; they appear across many research peptides built for improved stability.
The compound was developed in the late 1980s and early 1990s by academic researchers investigating melanocortin signaling and pigmentation. Early work explored whether synthetic analogs could reproduce effects of the natural hormone under controlled conditions. The molecule never advanced through the full regulatory pathway required for approval as a medicine. From the mid-2000s onward it appeared in unregulated consumer markets, often distributed through informal channels. That gap between research origins and commercial availability shapes how the compound is discussed today.
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.
Published human data come mostly from small, short studies rather than large controlled trials. Reported outcomes include increased skin pigmentation and, in some reports, effects on appetite and libido, but sample sizes are small and follow-up is limited. Whether long-term use produces durable pigment changes or adverse effects is not established. Because products sold outside pharmacies are not standardized, the actual content of any given vial is often unknown. Independent testing of such material is uncommon.
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.
=== Mid cap indices === Russell 2500 Index: A mid-cap to small-cap index of the bottom 2,500 stocks in the Russell 3000 Index. The Russell Top 500 Index plus the Russell 2500 Index yields the Russell 3000 Index. Russell Midcap Index: The bottom 800 stocks in the Russell 1000 Index. The Russell Top 200 Index plus the Russell Midcap Index yields the Russell 1000 Index.
== Selected awards and honors == 1977 E. Mead Johnson Award for Pediatric Research, New York, NY. 1987 Distinguished Alumnus Award, New Jersey College of Medicine, Newark, NJ. 1994 Selected as one of "The POZ 50," individuals who have most influenced the course of HIV/AIDS. 1995 AmFAR's Outstanding Research in Pediatric AIDS Award. Presented on World's AIDS Day. 2000 American Society of Microbiology Heroes in Medicine Award 2001 Research in Action Award. Presented by Treatment Action Group. December 8, 2001. New York, NY. 2007 Wheaton College Outstanding Alumnus Award for Service to Humanity 2010/2011 Purpose Prize Fellow Encore Career for continued dedication to issues of justice and equity. 2013 Bakken Invitation Honoree.
=== G04BD Drugs for urinary frequency and incontinence === G04BD01 Emepronium G04BD02 Flavoxate G04BD03 Meladrazine G04BD04 Oxybutynin G04BD05 Terodiline G04BD06 Propiverine G04BD07 Tolterodine G04BD08 Solifenacin G04BD09 Trospium G04BD10 Darifenacin G04BD11 Fesoterodine G04BD12 Mirabegron G04BD13 Desfesoterodine G04BD14 Imidafenacin G04BD15 Vibegron
Sources: en.wikipedia.org
== Causes == Cholecystitis occurs when the gallbladder becomes inflamed. Gallstones are the most common cause of gallbladder inflammation but it can also occur due to blockage from a tumor or scarring of the bile duct. The greatest risk factor for cholecystitis is gallstones. Risk factors for gallstones include female sex, increasing age, pregnancy, oral contraceptives, obesity, diabetes mellitus, ethnicity (Native North American), rapid weight loss.
Nanoscale secondary ion mass spectrometry (NanoSIMS) is an analytical instrument manufactured by CAMECA which operates on the principle of secondary ion mass spectrometry. The NanoSIMS is used to acquire nanoscale resolution measurements of the elemental and isotopic composition of a sample. The NanoSIMS is able to create nanoscale maps of elemental or isotopic distribution, parallel acquisition of up to seven masses, isotopic identification, high mass resolution, subparts-per-million sensitivity with lateral resolution down to 30 nm.
Pharmacotherapy, also known as pharmacological therapy or drug therapy, is defined as medical treatment that utilizes one or more pharmaceutical drugs to improve ongoing symptoms (symptomatic relief), treat the underlying condition, or act as a prevention for other diseases (prophylaxis). It can be distinguished from therapy using surgery (surgical therapy), radiation (radiation therapy), movement (physical therapy), or other modes. Among physicians, sometimes the term medical therapy refers specifically to pharmacotherapy as opposed to surgical or other therapy; for example, in oncology, medical oncology is thus distinguished from surgical oncology. Today's pharmacological therapy has evolved from a long history of medication use, and it has changed most rapidly in the last century due to advancements in drug discovery. The therapy is administered and adjusted by healthcare professionals according to the evidence-based guidelines and the patient's health condition. Personalized medicine also plays a crucial role in pharmacological therapy. Personalized medicine, or precision medicine, takes account of the patient's genetic variation, liver function, kidney function, etc, to provide a tailor-made treatment for a patient. In pharmacological therapy, pharmacists will also consider medication compliance. Medication compliance, or medication adherence, is defined as the degree to which the patient follows the therapy that is recommended by the healthcare professionals.
Sources: en.wikipedia.org
=== Allergy === A study published online in March 2008 showed that Colostrinin is non-allergenic and can prevent allergic inflammation due to common indoor and outdoor allergens. The study used a well characterized mouse model of allergic airway inflammation. Colostrinin (given orally, intranasally or intraperitoneally) significantly decreased IgE/IgG1 production, airway eosinophilia, mucin production and hypersensitivity induced by allergenic extracts from ragweed pollen and house dust mites. In contrast, colostrum induced positive inflammatory responses.
== Terminology == Growth hormone (GH l) is also called somatotropin (British: somatotrophin). The human form of growth hormone is known as human growth hormone, or hGH (ovine growth hormone, or sheep growth hormone, is abbreviated oGH). GH can refer either to the natural hormone produced by the pituitary (somatotropin), or biosynthetic GH for therapy. Cadaver growth hormone is the term for GH extracted from the pituitary glands of human cadavers between 1960 and 1985 for therapy of deficient children. In the U.S., cadaver GH, also referred to as NPA growth hormone, was provided by the National Pituitary Agency, and by other national programs and commercial firms as well. In 1985 it was associated with the development of Creutzfeldt–Jakob disease, and was withdrawn from use. RHGH (rHGH, rhGH) refers to recombinant human growth hormone, that is, somatropin (INN). Its amino acid sequence is identical with that of endogenous human GH. It is coincidental that RHGH also refers to rhesus monkey GH (RhGH), using the accepted naming convention of Rh for rhesus. Rhesus growth hormone was never used by physicians to treat human patients, but rhesus GH was part of the lore of the underground anabolic steroid community in those years, and fraudulent versions may have been bought and sold in gyms. met-GH refers to methionyl–growth hormone, that is, somatrem (INN). This was the first recombinant GH product marketed (trade name Protropin by Genentech). It had the same amino acid sequence as human GH with an extra methionine at the end of the chain to facilitate the manufacturing process.
=== Tenure === On August 12, 2022, Stansbury voted to pass the Inflation Reduction Act of 2022. According to a FiveThirtyEight analysis, during the 117th Congress, she voted with President Joe Biden's stated position 100% of the time. When President Donald Trump entered the House chamber for the 2025 Joint Session of Congress, Stansbury held a sign that said "this is not normal" to protest the mass firing of federal workers.
=== Lithium === Lithium which is used in the treatment of bipolar disorder was the first natural GSK-3 inhibitor discovered. It inhibits GSK-3 directly by competition with magnesium ions and indirectly by phosphorylation and auto-regulation of serine. Lithium has been found to have insulin-like effects on glucose metabolism, including stimulation of glycogen synthesis in fat cells, skin, and muscles, increasing glucose uptake, and activation of GS activity. In addition to inhibition of GSK-3, it also inhibits other enzymes involved in the regulation of glucose metabolisms, such as myo-inositol-1-monophosphatase and 1,6 bisphosphatase. Also, it has shown therapeutic benefit in Alzheimer's and other neurodegenerative diseases such as epileptic neurodegeneration.
Sources: en.wikipedia.org
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.
It was developed in the 1980s by researchers investigating analogues of alpha-melanocyte-stimulating hormone for pigmentation and related endpoints. Early work included small human studies during the 1990s. Development did not progress to licensing, and the compound remained a research and grey-market item.
Peptides are prone to truncation, oxidation and aggregation during synthesis and handling. Without independent testing, a buyer cannot confirm the identity or the content of a vial. Analytical surveys of unapproved peptide products have repeatedly found discrepancies between label claims and measured composition.
No. It is a synthetic analogue carrying four amino acid changes, a lactam ring and an amidated C-terminus. The natural hormone is a linear thirteen-amino-acid peptide processed from proopiomelanocortin.