MC1R raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2026-05-15 and is reviewed periodically as new material appears.
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.
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.
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.
Research interest has centred on photoprotection and pigmentation, with a smaller body of work on appetite and sexual function. Published human data remain limited to small, frequently uncontrolled studies, and the compound has never received marketing approval from a national medicines regulator. Most laboratory work treats it as a pharmacological tool for probing melanocortin signalling in cell culture or animal models. Whether pigmentation changes observed in people translate into measurable protection against ultraviolet-induced DNA damage 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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic cyclic heptapeptide | Analog of alpha-MSH with an internal lactam bridge |
| Molecular weight | Approximately 1024 daltons | Free base value; salt forms differ |
| Appearance | White to off-white powder | Usually supplied as a lyophilized solid |
| Solubility | Freely soluble in water | Poorly soluble in nonpolar solvents |
| Typical storage | −20 °C, dry, protected from light | Repeated freeze-thaw cycles degrade peptides |
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 analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its structure substitutes a lactam bridge between side chains to increase stability relative to the native hormone. The compound is also known by the shorthand MT-II and by several non-proprietary synonyms used in research catalogues. It is not an approved therapeutic product in any major jurisdiction; material sold under this name is typically offered as a laboratory reagent rather than as a medicine.
Early published reports described melanotan-2 as a tanning agent without sun protection, which means darkening is not the same as protection against ultraviolet radiation. Later studies explored the peptide in erectile dysfunction, hemorrhagic shock, and some skin conditions. No regulator in the United States or Europe has approved it for clinical use. Many products labelled melanotan-2 are sold without approval and their identity and purity are unverified. Its long-term safety in humans remains an open question.
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.
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.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, a naturally occurring peptide involved in pigmentation signalling. Its sequence incorporates modified residues that increase potency and extend biological activity relative to the native hormone. The compound binds receptors of the melanocortin family and is examined mainly in laboratory research. It does not occur naturally and exists only as a manufactured chemical entity produced by solid-phase synthesis.
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.
The Meiji era saw a flowering of public and intellectual discourse on the direction of Japan. Works like Nakae Chōmin's A Discourse by Three Drunkards on Government debated how best to blend the new influences coming from the West with local Japanese culture. Grassroots movements like the Freedom and People's Rights Movement called for the establishment of a formal legislature, civil rights, and greater pluralism in the Japanese political system. Journalists, politicians, intellectuals and writers actively participated in the movement, which attracted an array of interest groups, including women's rights activists. The elite class of the Meiji era adapted many aspects of Victorian taste, as seen in the construction of Western-style pavilions and reception rooms called yōkan or yōma in their homes. These parts of Meiji homes were displayed in popular magazines of the time, such as Ladies' Graphic, which portrayed the often empty rooms of the homes of the aristocracy of all levels, including the imperial palaces. Integrating Western cultural forms with an assumed, untouched native Japanese spirit was characteristic of Meiji society, especially at the top levels, and represented Japan's search for a place within a new world power system in which European colonial empires dominated.
Many public health initiatives are moving towards a more standardized approach at multiple levels: among local facilities (especially long-term and acute care), regional hospitals, national institutions, and global practices. A standardized approach of prevention may help to more effectively reduce the emergence of CRE. An infection control plan was implemented at the Kaplan Medical Center in Israel to control a hospital outbreak of carbapenem-resistant K. pneumoniae. The comprehensive plan included guidelines for cohorting patients in separate locations, cleaning with 1,000 ppm hypochlorite, screening for isolates from rectal swabs, and distribution of educational instruction sheets, lectures for all medical staff, and training. The hospital also implemented an automated computer system that updated patient charts when new cases were reported, if patients were carriers, and what precautions to take when dealing with such patients. This plan was evaluated in a quasiexperimental study through the incidence of clinical cases, the rate of cross-infection, and the rate of screening for carriage in admitted patients with increased risk of carriage. The study had a 16-fold decrease in the incidence of resistant K. pneumoniae, which was sustained for 30 months. The plan can provide a model for other hospitals to contain outbreaks of carbapenem-resistant bacteria. A reduction in the use of unnecessary invasive devices, including urinary catheters, could help reduce CRE transmission.
Dendroaspis natriuretic peptide (DNP) is a 38-residue peptide and a member of natriuretic peptide family. It is structurally similar to the atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP) and possesses biologic properties similar to these natriuretic peptides. DNP was originally isolated from the venom of the green mamba snake (Dendroaspis angusticeps), from which its name is derived.
== Etymology == The word Portugal derives from Latin Portus Cale, a Roman name meaning 'port of Cale', itself the origin of the name of the Portuguese city of Porto, while Cale was a town on the Douro. There is no consensus on the etymology of Cale. It could derive from the pre-Indo-European word Kala, meaning 'shelter' or 'refuge', passed into the Celtic language in the form Cale, with the meaning of 'land' or 'mountain'. The ethnonym Calaico/a then came from the Gallaeci, Celtic peoples of northwestern Iberia, and came to mean 'one of the land' or 'one of the place. During the Middle Ages, the region around Portus Cale became known by the Visigoths as Portucale and by the Suebi as Parochiale. The name Portucale evolved into Portugale; by the 11th and 12th centuries Portugal referred to the region between the Douro and Minho rivers.
Sources: en.wikipedia.org
double helix The shape most commonly assumed by double-stranded nucleic acid molecules, resembling a ladder that has been twisted upon its long axis, with the rungs of the ladder consisting of paired nucleobases. This secondary structure is the most energetically stable conformation of the double-stranded forms of both DNA and RNA under most naturally occurring conditions, arising as a consequence of the primary structure of the phosphodiester backbone and the stacking of the nucleotides bonded to it. In B-DNA, the most common DNA variant found in nature, the double helix has a right-handed twist with about 10 base pairs per full turn, and the molecular geometry results in an alternating pattern of "grooves" of differing widths (a major groove and a minor groove) between the parallel backbones.
A large overdose can cause asphyxia and death by respiratory depression if the person does not receive medical attention immediately. Overdose treatment includes the administration of naloxone. The latter completely reverses morphine's effects but may result in the immediate onset of withdrawal in opiate-addicted subjects. Multiple doses may be needed as the duration of action of morphine is longer than that of naloxone.
=== 19th century === Building on earlier studies, further glimpses of developmental bioelectricity occurred with the discovery of wound-related electric currents and fields in the 1840s, when the electrophysiologist Emil du Bois-Reymond reported macroscopic level electrical activities in frog, fish and human bodies. He recorded minute electric currents in live tissues and organisms with a then state-of-the-art galvanometer made of insulated copper wire coils. He unveiled the fast-changing electricity associated with muscle contraction and nerve excitation – the action potentials. Du Bois-Reymond also reported in detail less fluctuating electricity at wounds – injury current and potential – he made to himself.
=== Function in pregnancy === Progesterone plays a crucial role in pregnancy by supporting fetal development and maintaining the pregnancy. It is involved in the menstrual cycle, implantation, and is required for pregnancy maintenance. During implantation, it plays a role in its preservation through modulating the maternal immune response and suppressing the inflammatory response. By decreasing the maternal immune response, progesterone can allow the pregnancy to be accepted. Progesterone prepares the endometrium for implantation, as the level of progesterone increases, the capillaries grow. These capillaries spread throughout the granulosa layer of cells which promotes vascularization and blood flow in the endometrium, ensuring an adequate blood supply to the developing placenta and fetus. On the other hand, when there is no pregnancy occurred, the level of progesterone will decrease, which leads to menstruation. This means that bleeding from women's menstruation is bleeding after progesterone withdrawal.
=== Combination ESG and pharmacologic therapy === ESG can safely be combined with weight loss medications to improve weight loss or prevent weight regain after the procedure. The daily injectable medication liraglutide showed greater total body weight loss when combined with ESG compared to ESG alone at 7 months (approximately 25% vs 20% respectively). Similar results are anticipated with other incretin agents, such as semaglutide and tirzepatide, though no studies have directly assessed these combinations.
Sources: en.wikipedia.org
It is a synthetic seven-amino-acid peptide modeled on alpha-melanocyte-stimulating hormone. It carries two non-natural substitutions and a cyclic bridge that increase its stability relative to the natural hormone. It circulates as a research chemical and is not an approved medicine.
Melanotan-1, also called afamelanotide, is a shorter linear analog with a different amino acid sequence and no lactam ring. It has been evaluated in formal clinical programs, while melanotan-2 has not. The two are distinct molecules and are not interchangeable.
No. Bremelanotide is a related but distinct cyclic peptide that reached approved status for one specific clinical indication. Melanotan-2 is a separate molecule with its own sequence and properties. Shared ancestry in the melanocortin family does not make them the same substance.
It is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, containing seven amino acids with a lactam ring and a D-configured phenylalanine residue. It is supplied as a lyophilised powder for laboratory research.