The short version of MC1R fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-06-25 and is reviewed periodically as new material appears.
Melanotan-2 is frequently confused with afamelanotide, a linear analogue authorised in the European Union for erythropoietic protoporphyria. The two compounds differ in chain length, ring structure and receptor selectivity, so findings for one cannot be transferred directly to the other. Published controlled human data on melanotan-2 remain sparse, and much of what circulates online derives from small studies or unpublished reports. Questions about effect size, dose-response behaviour and long-term safety therefore remain unresolved.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone. Its sequence incorporates a lactam bridge that constrains the peptide into a ring, which increases resistance to enzymatic breakdown relative to the natural hormone. Researchers at the University of Arizona synthesised the compound in the late 1980s and early 1990s while studying pigmentation pathways. It has never received marketing approval from any national medicines regulator. In the scientific literature it is usually described as a laboratory research reagent rather than a therapeutic product.
The peptide acts as a non-selective agonist at melanocortin receptors, showing affinity for MC1R, MC3R, MC4R and MC5R. Activation of MC1R on melanocytes drives the conversion of tyrosine into melanin and shifts production toward the darker eumelanin form. MC4R signalling in the central nervous system is linked to appetite and energy balance, which helps explain why reduced food intake appeared in early human studies. Effects on MC4R and on vascular tone also account for the erectile responses recorded as unexpected findings in those same trials.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Alpha-MSH analogue with a lactam ring |
| Molecular formula | C50H69N15O9 | Commonly cited value for the neutral peptide |
| Molecular weight | 1024.18 g/mol | Calculated for the free molecule |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water, DMSO and ethanol | Dissolution in pure water is often slow |
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.
or the ratio of the thickness of the interfacial layer to the particle size. This model was shown to be more in agreement with the experimental results, but is limited in its applicability for there is not yet a theoretical way to establish the thermal conductivity, or the thickness of this layer.
Flavoring are often added to e-liquids as well as dry smoke blends. There are currently over 7,700 e-liquid flavors available, most have not been laboratory tested for toxicity. There are numerous flavors (e.g., fruit, vanilla, caramel, coffee) of e-liquid available. There are also flavorings that resemble the taste of cigarettes.
deoxyribose Also 2-deoxyribose. A monosaccharide pentose sugar derived from ribose by the replacement of the hydroxyl group attached to the C2 carbon with a single hydrogen atom. D-deoxyribose, in its cyclic ring form, is one of three main functional groups of deoxyribonucleotides and hence of deoxyribonucleic acid (DNA) molecules.
=== In cellular biology === It is also used in cellular biology as an inhibitor of the lipid raft-caveolae endocytosis pathway on mammalian cells, at concentrations around 3 μg/ml. Nystatin is also used as a tool by scientists performing "perforated" patch-clamp electrophysiological recordings of cells. When loaded in the recording pipette, it allows for measurement of electrical currents without washing out the intracellular contents, because it forms pores in the cell membrane that are permeable to only monovalent ions, preferably cations such as sodium, potassium, lithium, and cesium.
Sources: en.wikipedia.org
=== Common names === There are many common names for S. divinorum, including sage of the diviners, ska maría pastora, seer's sage, yerba de la pastora, simply salvia, and colloquially sally-d and magic mint.
Because failure to properly carry out any one of the components can severely affect the usefulness of using drug concentrations to optimize therapy, an organized approach to the overall process is critical.
Hemoglobin D – (α2βD2) – A variant form of hemoglobin. Hemoglobin H (β4) – A variant form of hemoglobin, formed by a tetramer of β chains, which may be present in variants of α thalassemia. Hemoglobin Barts (γ4) – A variant form of hemoglobin, formed by a tetramer of γ chains, which may be present in variants of α thalassemia. Hemoglobin S (α2βS2) – A variant form of hemoglobin found in people with sickle cell disease. There is a variation in the β-chain gene, causing a change in the properties of hemoglobin, which results in sickling of red blood cells. Hemoglobin C (α2βC2) – Another variant due to a variation in the β-chain gene. This variant causes a mild chronic hemolytic anemia. Hemoglobin E (α2βE2) – Another variant due to a variation in the β-chain gene. This variant causes a mild chronic hemolytic anemia. Hemoglobin AS – A heterozygous form causing sickle cell trait with one adult gene and one sickle cell disease gene Hemoglobin SC disease – A compound heterozygous form with one sickle gene and another encoding hemoglobin C. Hemoglobin Hopkins-2 – A variant form of hemoglobin that is sometimes viewed in combination with hemoglobin S to produce sickle cell disease.
==== Singapore ==== Taco Bell in Singapore existed for a number of years, mostly as combination stores with KFC such as the one that operated at the Funan Digital Life Mall, but in 2008, Taco Bell completely pulled out of Singapore.
The Genetics & IVF Institute (GIVF) is an international provider of infertility and genetics services and products, and also engages in biomedical research in these fields. The Institute was founded in 1984 by Dr. Joseph D. Schulman and associates. GIVF headquarters are in Fairfax, VA, US, and its facilities include locations in Pennsylvania, Minnesota, California, and Texas in the United States, as well as in China, Mexico, and several other countries. Genetics & IVF Institute has been responsible for numerous key innovations to help couples have healthy babies and to improve the reproductive health of women. These include: First U.S. medical center to introduce non-surgical ultrasound guided egg retrieval (transvaginal oocyte retrieval) for IVF; achieved America's first frozen embryo twin birth; first American team to publicly report pregnancies using ICSI (intracytoplasmic sperm injection); first to offer clinical laboratory testing for certain mutations in the BRCA1 and BRCA2 genes which cause hereditary breast cancer; developed the important technique of non-surgical sperm aspiration for improved treatment of male infertility; first in the world to initiate ovarian cryopreservation for storage of oocytes for women with cancer; discovered a method (non-disclosing preimplantation genetic testing) for the effective prevention of Huntington disease; developed MicroSort, an important flow-cytometric human sperm separation technique for preconceptual gender selection.
Sources: en.wikipedia.org
It is a synthetic cyclic heptapeptide modelled on alpha-melanocyte-stimulating hormone. A lactam bridge links two side chains, forming a ring that stabilises the molecule against proteolysis. It belongs to the broader melanocortin peptide family.
No national medicines agency has approved melanotan-2 for clinical use. Afamelanotide, a related but distinct peptide, holds a marketing authorisation in the European Union for a rare photosensitivity disorder. Melanotan-2 itself is handled as a laboratory chemical.
Its broad activity across melanocortin receptors makes it a tool for probing pigmentation, appetite and vascular signalling. Early trials recorded skin darkening and other effects that were not the original focus of the work. Those observations generated hypotheses that later studies have examined.
No regulator in a major market has approved it for human use. It appears in research settings and in products marketed outside pharmacy channels. Legal status for personal possession varies by country.