The short version of Heptapeptide fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-05-17 and is reviewed periodically as new material appears.
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.
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.
Activity is attributed to agonism at melanocortin receptors, particularly MC1R and MC4R. Activation of MC1R on melanocytes increases melanin synthesis, which underlies the reported tanning effect. MC4R engagement in the central nervous system is linked to appetite suppression and to effects on sexual arousal reported in early clinical studies. Those studies were small and were not designed to establish efficacy or long-term safety. Receptor selectivity among the melanocortin subtypes is not absolute, which complicates attribution of any effect to a single pathway.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | Melanotan II; MT-II; N-acetyl-norleucyl-cyclo[Asp-His-D-Phe-Arg-Trp-Lys] amide | Naming follows peptide convention; the numeral distinguishes it from melanotan-1 |
| Molecular formula | C50H69N15O9 | Includes the lactam bridge; no counter-ion assumed |
| Monoisotopic mass | 1023.53 Da | Free base; salts and counter-ions shift the observed value |
| Appearance | White to off-white lyophilised powder | Batch-to-batch colour variation is not itself proof of impurity |
| Typical analytical method | RP-HPLC purity determination with ESI-MS identity confirmation | Retention time alone does not establish sequence identity |
Melanocytes are the pigment-producing cells of the skin, and they carry melanocortin-1 receptors on their surface. When the receptor is activated, cyclic adenosine monophosphate rises inside the cell and raises the activity of enzymes such as tyrosinase, which increases melanin output. Melanotan-2 binds melanocortin-1 receptors in vitro and in animal models, and this binding is generally described as the basis for the tanning effect. Other receptors account for different effects: melanocortin-4 receptors contribute to appetite and erectile signalling, while melanocortin-3 and melanocortin-5 receptors contribute to energy balance and exocrine function.
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.
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.
Of the two fungal groups with the largest number of species in Malaysia, the Ascomycota and their asexual states have been surveyed in some habitats (decaying wood, marine, and freshwater ecosystems, as parasites of some plants, and as agents of biodegradation), but have not been or have been only poorly surveyed in other habitats (as endobionts, in soils, on dung, as human and animal pathogens); the Basidiomycota are only partly surveyed: bracket fungi, mushrooms and toadstools have been studied, but Malaysian rust and smut fungi remain little known. Without a doubt, many more fungal species in Malaysia are yet to be recorded, and it is likely that many of those, when found, will be new to science.
=== Reduction of endogenous quinones === NQO1 plays a role in ubiquinone and vitamin E quinone metabolism. These quinones protect cellular membranes from peroxidative injury in their reduced state. Furthermore, reduced forms of ubiquinone and vitamin E quinone have been shown to possess antioxidant properties that are superior to their non-reduced forms.
An ongoing conflict between the Lebanese militant group Hezbollah and Israel began on 8 October 2023, when Hezbollah launched rockets and artillery at Israeli positions following Hamas's October 7 attacks on Israel. The conflict escalated into a prolonged exchange of bombardments, leading to extensive displacement in Israel and Lebanon. The conflict is part of the broader Middle Eastern crisis that began with Hamas's attack, with the short Israeli invasion of Lebanon in 2024 marking the largest escalation of the Hezbollah–Israel conflict since the 2006 Lebanon War. In Arabic, the conflict (2023–2024) is referred to as the "Support War" or the "Gaza Support War." On 8 October 2023, Hezbollah started firing guided rockets and artillery shells at Israeli positions in the Shebaa Farms, which it said was in solidarity with Palestinians following the 7 October Hamas-led attack on Israel and beginning of Israeli bombing of the Gaza Strip. Israel retaliated by launching drone strikes and artillery shells at Hezbollah positions. Israel also carried out airstrikes throughout Lebanon and in Syria. In northern Israel, the ongoing conflict has forced approximately 96,000 individuals to leave their homes, while in Lebanon, over 1.4 million individuals had been displaced by late October. Hezbollah stated it would not stop attacks against Israel until it stops its military operations in Gaza; Israel said its attacks would continue until its citizens could return safely to the north.
Because of such differences, the rules determining biological injury differ widely according to the radioisotope, time of exposure, and sometimes also the nature of the chemical compound which contains the radioisotope.
== Adverse effects == Safety and dosing trials showed that the incidence of adverse events in orforglipron-treated participants was 62–89%, mostly from gastrointestinal discomfort (44–70% with orforglipron, 18% with placebo); in patients experiencing adverse events, 96% had mild to moderate GI side effects, while approximately 4% had severe nausea or vomiting. The most common side effects of orforglipon noted in clinical trials were vomiting, diarrhea, nausea, upset stomach, and constipation.
Sources: en.wikipedia.org
The use of fermentation, particularly for beverages, has existed since the Neolithic and has been documented dating from 7000 to 6600 BCE in Jiahu, China, 6000 BCE in Georgia, 3150 BCE in ancient Egypt, 3000 BCE in Babylon, 2000 BCE in pre-Hispanic Mexico, and 1500 BC in Sudan. Fermented foods have a religious significance in Judaism and Christianity. The Baltic god Rugutis was worshiped as the agent of fermentation.
In the Cape Colony, increasing tensions between some Dutch Settlers and the British colonial authorities led to a wave of Boer (also known as Voortrekkers) migration northwards from 1836 onwards in order to establish autonomous Boer states independent of British control. The Boers settlers began moving across the Orange River northwards. While travelling they first collided with the Ndebele kingdom, and then with Dingane's Zulu kingdom. In October 1837, the Voortrekker leader Piet Retief visited Dingane at his royal kraal to negotiate a land deal for the voortrekkers. In November, about 1,000 Voortrekker wagons began descending the Drakensberg mountains from the Orange Free State into what is now KwaZulu-Natal. Dingane asked that Retief and his party retrieve some cattle stolen from him by a local chief as part of the treaty for land for the Boers. This Retief and his men did, returning on 3 February 1838. The next day, a treaty was signed, wherein Dingane ceded all the land south of the Tugela River to the Mzimvubu River to the Voortrekkers. Celebrations followed. On 6 February, at the end of the celebrations, Retief's party were invited to a dance, and asked to leave their weapons behind. At the peak of the dance, Dingane leapt to his feet and yelled "Bambani abathakathi!" (isiZulu for "Seize the wizards"). Retief and his men were overpowered, taken to the nearby hill kwaMatiwane, and executed. Some allege that they were killed for withholding some of the cattle they recovered, but it is likely that the deal was a plot to overpower the Voortrekkers.
By using life cycle assessment tools he demonstrated the shortcomings of bioplastics and similar biomass based technologies intended as a substitute for the petrochemical processes used today. His main findings showed that changing from petrochemical to biomass-based processes often worsens their environmental impact and increases the emissions of carbon dioxide when compared to conventional processes based on fossil fuel stocks. With the recent mandate to increase biofuel content in the United States this area of research has become increasingly important, but to date has failed to guide public policy in the United States. Arguably, Gerngross' most important biotechnological contribution consisted of humanizing the glycosylation machinery in yeast to produce human therapeutic proteins, including antibodies, with fully human carbohydrate structures. Much of this work was conducted at Glycofi, Inc., a Lebanon, New Hampshire biotechnology startup company that was acquired in 2006 by Merck in a record-setting $400 million transaction. His work has been frequently cited in the popular press including The Times (London), CNN, Scientific American, BBC, The Guardian, The Economist, New Scientist, Nature Biotechnology and the Los Angeles Times. He has most recently been covered by the Boston Globe, CNBC, First Rounders, Evaluate Pharma, STAT and numerous others.
== Isotherms == The adsorption of gases and solutes is usually described through isotherms, that is, the amount of adsorbate on the adsorbent as a function of its pressure (if gas) or concentration (for liquid phase solutes) at constant temperature. The quantity adsorbed is nearly always normalized by the mass of the adsorbent to allow comparison of different materials. A number of different isotherm models have been developed.
Sources: en.wikipedia.org
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.
The natural hormone is a linear tridecapeptide that is rapidly degraded in circulation. Melanotan-2 is shortened, cyclised, N-terminally acetylated, and carries a D-amino acid substitution, all of which slow enzymatic breakdown.
No national medicines regulator has approved melanotan-2 for therapeutic or cosmetic use. In several jurisdictions it is treated as an unapproved prescription medicine, and its legal classification differs from country to country.
No. No major regulatory agency has granted a marketing authorisation for melanotan II as a medicine. Products sold under this name are generally presented as laboratory reagents and are not subject to the batch-release testing applied to approved drugs.