This is a working overview of lyophilised powder, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-12-24 and is reviewed periodically as new material appears.
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.
Melanotan-2 appears on the World Anti-Doping Agency prohibited list within the peptide hormone class, and several national regulators treat it as an unapproved prescription substance. Some countries restrict importation or sale for personal use. Because the compound is widely traded as a research chemical, the practical legal picture differs between jurisdictions and shifts over time. Human safety data covering long periods are limited, and whether repeated pigmentation changes carry any lasting risk to melanocytes remains an open question.
Freeze-dried melanotan-2 is normally kept as a desiccated powder at minus twenty degrees Celsius or lower, shielded from light and moisture. Peptides of this size degrade through hydrolysis, oxidation and deamidation, and each pathway accelerates as temperature and water activity rise. Repeated freeze-thaw cycles promote aggregation and loss of material, so aliquoting a stock solution before freezing is standard laboratory practice. Once dissolved, the solution is markedly less stable than the powder. In laboratory work, solutions are generally refrigerated and used within days rather than kept for months.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Analog of alpha-melanocyte-stimulating hormone |
| Primary receptor family | Melanocortin receptors MC1R through MC5R | Binding is not subtype-selective |
| Development period | 1980s | Synthesized during pigmentation and appetite research |
| Regulatory status | Not an approved medicine | No major regulator has authorized human use |
| Related compound | Afamelanotide | Linear analog studied for photoprotection |
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.
Published pharmacokinetic information is limited and comes mainly from small studies rather than registrational trials. Plasma half-life is usually described as short, on the order of tens of minutes, followed by rapid tissue distribution and clearance of the intact peptide. Metabolites and low concentrations of parent compound have been reported in urine, a detail relevant to anti-doping and forensic testing. Whether repeated exposure changes receptor sensitivity or clearance over time remains an open question. Values differ noticeably between analytical assays, so published numbers should be read as approximate rather than definitive.
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.
Lyophilised melanotan-2 is supplied as a solid, which is more stable than a solution. The material is hygroscopic, so weighing is done quickly, in low humidity, with the container kept sealed. Reconstitution usually uses water for injection or bacteriostatic water, added down the wall of the vial to limit foaming. A reconstituted solution is held at 2 to 8 °C and kept away from light. Repeated freezing and thawing of the same vial is avoided because ice crystal formation and concentration effects degrade the peptide.
Reversed-phase high-performance liquid chromatography is the routine method for purity assessment. Peptides absorb near 214 nm because of the peptide bond, and a gradient of acetonitrile in water separates the intact peptide from deletion sequences, oxidised products, and earlier-eluting fragments at neutral pH. Electrospray ionisation mass spectrometry provides an orthogonal check: the measured mass must agree with the theoretical value. Amino acid analysis and peptide mapping confirm structure but are used less often. Reference standards remain scarce because the peptide is not described in any pharmacopoeia.
Iron is required for life. The iron–sulfur clusters are pervasive and include nitrogenase, the enzymes responsible for biological nitrogen fixation. Iron-containing proteins participate in transport, storage and use of oxygen. Iron proteins are involved in electron transfer. The ubiquity of Iron in life has led to the Iron–sulfur world hypothesis that iron was a central component of the environment of early life.
=== Building blocks for cell-adhesion === By looking at the genome of the Choanoflagellate, "Monosiga brevicollis", scientists have inferred that choanoflagellates play a key role in the development of multicellularity. Nicole King has done work looking at the genome of Monisiga brevicollis, and has found key protein domains that are shared between metazoans and choanoflagellates. These domains play a role in cell signalling and adhesion processes in metazoans. The finding that choanoflagellates also have these genes is an incredible discovery because it was previously thought that only metazoans had genes responsible for cell-cell communication and aggregation. This suggests that these domains play a key role in the origins of multicellularity since it ties a unicellular organism (choanoflagellates) to multicellular organisms (metazoans). It shows that the components required for multicellularity were present in the common ancestor between metazoans and choanoflagellates.
=== Guidance on interpretation of BPE scores === A myriad of factors, which are patient specific, can affect the BPE scores derived. Hence, dental professionals should use their expertise, knowledge and experience to form a reasonable decision when interpreting BPE scores. The BPE scores should be taken into account alongside other factors when being interpreted. A general guideline is:
==== Ion exchange ==== Ion exchange is a reversible ion exchange process in which an insoluble substance (resin) takes ions from an electrolytic solution and releases additional ions of the same charge in a chemically comparable amount without changing the resin's structure.
Fatoumata Binta Diallo - First woman who registered to practice law in the Bar of the Republic of Guinea Conakry. Bachir Diallo - Minister of Security and Civil Protection, Guinea. Facinet Sylla - Minister of Budget, former executive director Of International Monetary Fund. Katoucha (Kadiatou Niane) – former model and fashion designer, Guinea Boubacar Yacine Diallo – Journalist, Writer, former Minister of Communication, former chairman of the National Council of Communication, Current vice president of the independent national institution for human rights in Guinea. Addi Bâ or Bah Mamadou Hady – called by the Germans "black terrorist" ("Der schwarze Terrorist"), a figure of the French resistance, member of the first scrub of the Vosges, Guinea Aïcha Bah Diallo – former Minister of Education and Women's Rights Activist, former Senior education leader at UNESCO. Hamidou Diallo – American professional basketball player. 2019 NBA All-Star Slam Dunk Contest winner Abou Sangaré - Mechanic and Actor, Best European Actor 2024 Rabiatou Sérah Diallo – Guinean trade unionist. former president of the National Transitional Council. Current president of Economic and Social Council, Guinea Black M (Alpha Diallo) – French rapper and Singer–Songwriter.
Sources: en.wikipedia.org
=== Role of the extracellular matrix and its components === Another difference between the healing of embryonic and adult wounds is due to the role of fibroblast cells. Fibroblasts are responsible for the synthesis of the ECM and collagen. In the fetus, fibroblasts are able to migrate at a faster rate than those found in the adult wound. Fetal fibroblasts can also proliferate and synthesize collagen simultaneously, in comparison to adult fibroblasts where collagen synthesis is delayed. It is this delay in both collagen deposition and migration, which is likely to contribute to formation of a scar in the adult. Proteins and cell surface receptors found in the ECM differ in fetal and adult wound healing. This is due to the early up regulation of cell adhesion proteins such as fibronectin and tenascin in the fetus. During early gestation in the fetal wounds of rabbits, the production of fibronectin occurs around 4 hours after wounding, much faster than in adult wounds where expression of fibronectin does not occur until 12 hours post wounding. The same pattern can be seen in the deposition of tenascin. It is this ability of the fetal fibroblast to quickly express and deposit fibronectin and tenascin, which ultimately allows cell migration and attachment to occur, resulting in an organised matrix with less scarring. Another major component of the ECM is hyaluronic acid (HA), a glycosaminoglycan. It is known that fetal skin contains more HA than adult skin due to the expression of more HA receptors.
==== Instant kelp tea ==== Powdery kelp tea is sold as an instant tea under the name of konbu-cha or kobu-cha. It is made by drying kombu to a fine powder and blending it with seasonings such as salt and sugar. It's simply dissolved in hot water and enjoyed as a tea. Note that this type of konbu-cha does not contain any true tea (Camellia sinensis). The powdery kelp tea was invented by the founder of GYOKUROEN "Umazou Fujita" in 1918. Ume-konbu-cha or ume-Kobu-cha, which is powdery kombu tea with freeze-dried crushed umeboshi, is also sold as an instant tea and is drunk as a tea in the same fashion.
Territories on both sides of the new Polish-Ukrainian border were also "ethnically cleansed". Of the Ukrainians and Lemkos living in Poland within the new borders (about 700,000), close to 95% were forcibly moved to the Soviet Ukraine, or (in 1947) to the new territories in northern and western Poland under Operation Vistula. In Volhynia, 98% of the Polish pre-war population was either killed or expelled; in Eastern Galicia, the Polish population was reduced by 92%. According to Timothy D. Snyder, about 70,000 Poles and about 20,000 Ukrainians were killed in the ethnic violence that occurred in the 1940s, both during and after the war. According to an estimate by historian Jan Grabowski, about 50,000 of the 250,000 Polish Jews who escaped the Nazis during the liquidation of ghettos survived without leaving Poland (the remainder perished). More were repatriated from the Soviet Union and elsewhere, and the February 1946 population census showed about 300,000 Jews within Poland's new borders.[e] Of the surviving Jews, many chose to emigrate or felt compelled to because of the anti-Jewish violence in Poland. Because of changing borders and the mass movements of people of various nationalities, the emerging communist Poland ended up with a mainly homogeneous, ethnically Polish population (97.6% according to the December 1950 census). The remaining members of ethnic minorities were not encouraged, by the authorities or by their neighbors, to emphasize their ethnic identities.[i][a1]
Tissue remodeling is the reorganization or renovation of existing tissues. Tissue remodeling can be either physiological or pathological. The process of remodeling is generally intended to be the change microscopic properties of a tissue . Remodeling has often the function of optimizing the mechanical properties of the tissue reacting to external stimulus and adapting to it, as it is the case of bone and blood vessel remodeling. Other important examples of tissue that undergo remodeling include: connective tissue under tension or that is undergoing wound healing, during which the Macrophages remodel the tissue by producing extracellular matrix and proteases to modify that specific matrix. Although remodeling happens in tissues that have very different functions, some general patterns can be identified. For those tissue that tend to optimize mechanical properties the cooperation of mechanotransductive components (serving as sensor) that communicate to actuators which will change physically the property (this two parts forming a control loop). This is the case of bone remodelling, where osteocytes perceive the principal direction of the stress applied to the bones and they comunicate it to the osteoblats and osteoclasts that reorient the trabecular structure as to align which such direction to make the tissue have a stiffer response to the strongest solicitations, without increasing weight needlessly (a phenomenon known historically as "Wolf's law").
Sources: en.wikipedia.org
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.
Afamelanotide is a linear analog that has received approval in some jurisdictions for a specific photoprotection indication. Melanotan II is cyclic and less selective across melanocortin receptors. The two are related but are not interchangeable in regulatory or clinical terms.
A compound that activates several receptor subtypes may produce effects beyond pigmentation. Selectivity influences which tissues respond and shapes the side-effect profile described in reports. Designing subtype-selective analogs is a stated goal of melanocortin research.
The lyophilised solid is best kept cold, dry and dark, typically at minus twenty degrees Celsius. Moisture and repeated warming cycles are the main causes of degradation. Solutions prepared from the powder are less stable and are normally used quickly.