en · de · es · fr · pt
melanotan-2-notes.peptides9002.com › News › Melanotan-2 Structure And Receptor Pharmacology — Reference Sheet

Melanotan-2 Structure And Receptor Pharmacology — Reference Sheet

By Editorial Desk · published 2026-02-26 · last reviewed 2026-04-01 · News

If you have been reading about Melanotan II and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.

Last reviewed on 2026-04-01. Where a claim depends on a specific study, the study is described rather than over-claimed.

Melanotan-2 Structure and Receptor Pharmacology

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.

Origins and Research Status

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 at a glance

PropertyValueNotes
Molecular formulaC50H69N15O9Free base; salt forms add to total mass
Molecular massAbout 1024 daltonsCalculated for the free base
Structural classCyclic heptapeptideContains D-phenylalanine and norleucine
Parent hormoneAlpha-melanocyte-stimulating hormoneEndogenous tridecapeptide of 13 residues
Receptor profileNon-selective melanocortin agonistInteracts with MC1R, MC3R, MC4R and MC5R

Further detail

In his return game, he had the fifth highest percentage of first serve points won that year at 32.4%. His second serve has been a weakness for him in his earlier years, yet he has managed to turn it into a consistent strength. Zverev hit the most double faults on tour in 2016 and 2020. While it has improved since, it can still cause trouble for the German in big points.

The divisions between the elite and the lawless led to the formation of a Cossack army, beginning in 1667 under Stenka Razin, and ultimately to the failure of Razin's rebellion. Stenka Razin was born into an elite Cossack family, and had made many diplomatic visits to Moscow before organizing his rebellion. The Cossacks were Razin's main supporters, and followed him during his first Persian campaign in 1667, plundering and pillaging Persian cities on the Caspian Sea. They returned in 1669, ill and hungry, tired from fighting, but rich with plundered goods. Russia tried to gain support from the old Cossacks, asking the ataman, or Cossack chieftain, to prevent Razin from following through with his plans. But the ataman was Razin's godfather, and was swayed by Razin's promise of a share of expedition wealth. His reply was that the elite Cossacks were powerless against the band of rebels. The elite did not see much threat from Razin and his followers either, although they realized he could cause them problems with the Muscovite system if his following developed into a rebellion against the central government. Razin and his followers began to capture cities at the start of the rebellion, in 1669. They seized the towns of Tsaritsyn, Astrakhan, Saratov, and Samara, implementing democratic rule and releasing peasants from slavery as they went. Razin envisioned a united Cossack republic throughout the southern steppe, in which the towns and villages would operate under the democratic, Cossack style of government.

== External links == MedlinePlus Encyclopedia: Gamma-glutamyl transpeptidase (GGT) blood test gamma-Glutamyltransferase at the U.S. National Library of Medicine Medical Subject Headings (MeSH) GGT - Lab Tests Online Overview of all the structural information available in the PDB for UniProt: P19440 (Gamma-glutamyltransferase 1) at the PDBe-KB.

Sources: en.wikipedia.org

Related pages on this site

Supporting material

== Adverse effects == Because bromazolam is relatively new, epidemiological research regarding the individual's health effects as well as the effects on the public health are quite scarce. Most of the knowledge about the effects are known from case studies and individual reports. The typical effects of benzodiazepines used in medical science are muscle relaxation, amnesia, sedation, anxiolysis and anticonvulsive activity (used to treat epilepsy). Therefore, benzodiazepines are frequently used to treat illnesses such as anxiety, insomnia, muscle spasms or epilepsy. Similarly to prescription benzodiazepines, bromazolam usage can lead to tolerance, addiction and dependence. Benzodiazepine-like compounds are rarely fatal when taken alone but can cause central nervous system depression when combined with other medication or drugs. Common adverse effects of benzodiazepines are somnolence, impaired balance, ataxia, loss of coordination, impaired thinking and self-assessment capability, muscle weakness, confusion, slurred speech, blurred vision, amnesia, dizziness, drowsiness, lethargy, fatigue and palpitations. At high doses, they may induce delirium, auditory and visual hallucinations, seizures, deep sleep and coma. To study the potential addictive nature of bromazolam a two-lever drug discrimination test was performed. Rats trained to discriminate against the benzodiazepine midazolam were used to evaluate the abuse potential of bromazolam. They found that bromazolam resulted in full dose-dependent substitution with an ED50 of 0.54 mg/kg.

=== Personal life === Humphreys married Nancy Wallace, a woman from a prominent Tulsa family, in 1960. The couple had two children, Claire and David. In 1974, Humphreys came out as a gay man during a discussion at a conference session at the ASA. Humphreys was a co-founder of the Sociologists' Gay Caucus (now the Committee on the Status of Lesbian, Gay, Bisexual, Transgender, and Queer People in Sociology), established in 1974 as a response to a presentation by Edward Sagarin that criticized homosexual sociologists as hiding in the closet. Humphreys separated from his wife in 1980 and began living with Brian Miller, a graduate student at the University of Alberta. With Miller, he co-authored articles about gay subcultures and victims of violent homophobia. Humphreys died of lung cancer on August 23, 1988, aged 57.

==== Materials, incubation and viability ==== Polydimethylsiloxane (PDMS) is the most common material to fabricate microfluidic devices due to low cost, ease of prototyping, and good gas permeability. Along with perfluorocarbon carrier oils, which also allow good gas permeability, used as a continuous phase in the droplet-based microfluidic system for cell culture, some studies have found that cell viability is comparable to culture in flasks, for example mammalian cells. To reach the required culture time, a reservoir or a delay line can be used. Using a reservoir allows long-term culture from several hours to several days while the delay line is suitable for short-term culture with several minutes. Incubation is feasible both on-chip (reservoir connected with a microfluidic system or delay lines) and off-chip (PTFE tubing isolated with a microfluidic system) after the droplets formed. After incubation, droplets can be reinjected into the microfluidic device for analysis. There are also specially designed on-chip droplet storage systems for direct analysis, such as the "dropspot" device, which stores droplets in several array chambers and uses microarray scanner for direct analysis.

Sources: en.wikipedia.org

Frequently asked questions

Is melanotan-2 approved for medical use?

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.

How does melanotan-2 differ from melanotan-1?

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.

What is the connection to alpha-MSH?

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.

What is melanotan II?

It is a synthetic cyclic peptide designed as an analog of alpha-melanocyte-stimulating hormone. It acts on melanocortin receptors and is best known from research into pigmentation. It is not an approved pharmaceutical product.

Network