A practical reference on alpha-MSH analog: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-01-13. Anything still debated is marked as such rather than presented as settled.
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 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 |
|---|---|---|
| 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-2 is a synthetic linear peptide built from seven amino acids arranged in a short chain. Its sequence is commonly written as Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH2, which includes a modified N-terminus and an amidated C-terminus. The molecule belongs to the melanocortin family and acts as a receptor agonist. Structural features such as the D-phenylalanine residue and the Nle substitution are associated with increased stability against enzymatic degradation relative to the natural parent peptide.
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.
Melanotan II is a synthetic peptide analog modeled on alpha-melanocyte-stimulating hormone, a naturally occurring signaling peptide involved in pigmentation. Its structure is a cyclic heptapeptide containing two non-natural substitutions, norleucine at position four and D-phenylalanine at position seven. These modifications resist enzymatic breakdown and extend the molecule's activity relative to the native hormone. The compound binds melanocortin receptors and is studied mainly as a pharmacological tool rather than a therapeutic product. It has never received approval as a medicine in any major jurisdiction.
The compound was developed in the late 1980s and 1990s by academic researchers investigating photoprotection. The rationale held that stimulating melanin production might reduce ultraviolet damage to skin and lower skin cancer risk. Early work examined receptor binding, pigment response, and short-term tolerability in small studies. That program did not produce an approved drug, and formal development stalled after early-phase trials. Whether induced pigmentation confers meaningful photoprotection remains an open question.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, the naturally occurring peptide involved in pigmentation signalling. Its sequence is conventionally written as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, with a lactam bridge joining the aspartate side chain to the lysine side chain. The empirical formula is C50H69N15O9 and the monoisotopic mass lies near 1023.5 daltons. N-terminal acetylation and the D-configured phenylalanine both increase resistance to enzymatic breakdown compared with the parent hormone.
Pharmacologically, melanotan-2 behaves as a non-selective agonist across the melanocortin receptor family. Binding at MC1R on dermal melanocytes promotes eumelanin synthesis, which underlies the tanning response described in early human work. Activity at the centrally expressed MC4R receptor is associated with reported effects on appetite and erectile function. Because the peptide does not discriminate strongly among receptor subtypes, attributing any single observed effect to one receptor pathway is generally not possible without selective antagonists or receptor knockout models.
For services to the Care of Wildlife in Northumberland. Walter Wilson Ross, Conductor, Pension Silver Band, East Lothian. For services to Music. Charles Routledge, Dresser. For services to the Theatre. David Walton Routledge. For services to the community in Hillingdon, Middlesex. Harold Rowling. For services to the community in Westmeston, East Sussex. Shantilal Hirji Ruparell. For services to the community in Harrow, Middlesex. James Edwin Rous Saltonstall. For services to Yachting and to Young People. Anne Mary Sankaran. For services to the community in Oldham, Lancashire. Peter Saunders, Chairman, Groundwork Trust, Merthyr and Cynon. For services to the Environment. Alan Digerson Savage. For services to the Croydon Battle of Britain Memorial and to the Royal Air Force Benevolent Fund. John Robert Savage. For services to the community in Southwell, Nottinghamshire. Leslie Daniel Sayer, . For services to the Telegraphist Air Gunners' Association. Barry Scaplehorn, lately Firefighter, Suffolk County Fire Service. For services to the Fire Services Benevolent Fund. Susan Scarsbrook, Head, Sudbourne Primary School, Lambeth, London. For services to Education. David Andrew Seaman. For services to Association Football. Peter Jonathan Seaman, lately Chief Inspector, Hertfordshire Constabulary. For services to the Police. Sukumar Sen. For services to the community in Lochaber. Dorothy Sewell. For services to the community in Middlesbrough, North Yorkshire. Robert James Shaw. For services to the Fishing Industry. Patrick John Sherwin. For services to Coastal Rowing.
Spironolactone, sold under the brand name Aldactone among others, is classed as a diuretic medication. It can be used to treat fluid build-up due to liver disease or kidney disease. It is also used to reduce risk of disease progression, hospitalization, and death due to some types of heart failure. Other uses include acne and excessive hair growth in women, low blood potassium that does not improve with supplementation, high blood pressure that is difficult to treat, and early puberty in boys. It is also used to block the effects of testosterone as a part of feminizing hormone therapy. Spironolactone is usually available in tablets, taken by mouth, though topical forms are also available. Common side effects include electrolyte abnormalities, particularly high blood potassium, nausea, vomiting, headache, rashes, and a decreased desire for sex. In those with liver or kidney problems, extra care should be taken. If taken during pregnancy, some animal studies suggest that spironolactone may affect the development of sex organs in babies. While this has not occurred in the few human studies available, women who are pregnant or considering pregnancy should discuss spironolactone use with their doctor due to the theoretical risk. Spironolactone is a steroid that blocks the effects of the hormones aldosterone, and to a lesser degree, testosterone, causing some estrogen-like effects. Spironolactone belongs to a class of medications known as potassium-sparing diuretics. Spironolactone was discovered in 1957, and was introduced in 1959.
== Disorders and conditions == Numerous reports have been published indicating that the glutamate/GABA–glutamine cycle is compromised in a variety of neurological disorders and conditions. Biopsies of sclerotic hippocampus tissue from human subjects with epilepsy have shown decreased glutamate–glutamine cycling. Another pathology in which the glutamate/GABA–glutamine cycle might be compromised is Alzheimer's disease; NMR spectroscopy showed decreased glutamate neurotransmission activity and TCA cycling rate in patients with Alzheimer's disease. Hyperammonemia in the brain, typically occurring as a secondary complication of primary liver disease and known as hepatic encephalopathy, is a condition that affects glutamate/GABA–glutamine cycling in the brain. Current research into autism also indicates potential roles for glutamate, glutamine, and/or GABA in autistic spectrum disorders.
Sources: en.wikipedia.org
== History == The FODMAP concept was first published in 2005. In this paper, it was proposed that a collective reduction in the dietary intake of all indigestible or slowly absorbed, short-chain carbohydrates would minimize stretching of the intestinal wall. This was proposed to reduce stimulation of the gut's nervous system and provide the best chance of reducing symptom generation in people with IBS (see below). At the time, there was no collective term for indigestible or slowly absorbed, short-chain carbohydrates, so the term FODMAP was created to improve understanding and facilitate communication of the concept. The low-FODMAP diet was originally developed by a research team at Monash University in Melbourne, Australia. The Monash team undertook the first research to investigate whether a low-FODMAP diet improved symptom control in patients with IBS and established the mechanism by which the diet exerted its effect. Monash University also established a rigorous food analysis program to measure the FODMAP content of a wide selection of Australian and international foods. The FODMAP composition data generated by Monash University updated previous data that was based on limited literature, with guesses (sometimes wrong) made where there was little information.
However, wildlife has much less PFOA than humans, unlike PFOS and other longer perfluorinated carboxylic acids; in wildlife, PFOA is not as bioaccumulative as longer perfluorinated carboxylic acids. Municipal wastewater and landfill leachates are considered as important sources of PFOA to the environment. Most industrialized nations have average PFOA blood serum levels ranging from 2 to 8 parts per billion; the highest consumer sub-population identified was in Korea—with about 60 parts per billion. In Peru, Vietnam, and Afghanistan blood serum levels have been recorded to be below one part per billion. In 2003–2004 99.7% of Americans had detectable PFOA in their serum with an average of about 4 parts per billion, and concentrations of PFOA in US serum have declined by 25% in recent years. Despite a decrease in PFOA, the longer perfluorinated carboxylic acid PFNA is increasing in the blood of US consumers. PFAS are also found in paper mill residuals, digestates, composts, and soils. Given the ubiquity of PFAS, and the comparative background levels which may be found in wastewater, biosolids, and leachates, setting requirements near analytical detection limits on these sources may not provide a discernable benefit to protecting public health.
In the above examples, neither whole rice nor canned chickpeas have sufficient amounts of all required amino acids when used as the only source of 46.2 g of daily protein. The insufficient amino acid is called the limiting amino acid: lysine in rice and methionine in chickpeas. Consuming only chickpeas or other plant-based foods that also lack methionine for long periods of time will result in deficiency of the amino acid, and severe health problems will arise.
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.
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.