prohibited list is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-06-04. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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 |
|---|---|---|
| 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 |
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.
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.
Regulatory treatment varies by country. In the United States, melanotan-2 is not approved for any indication, and products marketed for human use fall outside the approved drug framework. Some other jurisdictions have placed it under prescription controls or listed it as a prohibited or restricted substance. Online listings frequently describe the material as a research chemical, a category that does not carry the same manufacturing and labelling requirements as approved medicines.
Solid peptide material is generally stable when kept cold and dry. Common practice is storage at -20 degrees Celsius or lower, with desiccant and protection from light. Repeated freeze-thaw cycles and exposure to moisture are associated with degradation, aggregation, or loss of material. Once dissolved, stability depends on solvent, concentration, and temperature, and solutions are usually treated as short-lived unless stability data support longer periods. Handling notes typically emphasise minimising time at ambient temperature.
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.
Regulatory treatment of this peptide varies by country. It holds no marketing authorization as a medicine in the United States, the European Union, or most other jurisdictions. Some countries classify products containing it as prescription-only or unlicensed medicines, which restricts lawful supply. Authorities have issued public notices warning that unregulated products may contain undeclared or incorrect ingredients. The molecule also appears on prohibited lists for competitive sport. These measures address supply oversight rather than any approved therapeutic role.
Published research on the compound remains limited. Much of the human data comes from small, early-stage studies rather than large controlled trials, and several questions about effects and variability between individuals remain open. Investigators have examined receptor activity, pigment pathways, and related physiological responses in laboratory and animal models. Findings from those models do not automatically translate to human outcomes. Reviews frequently note the scarcity of rigorous clinical evidence and call for better-characterized study material.
=== Other === In perfumery, it is used as a fixative to lower the evaporation rate and improve stability. It is used industrially as a stabilizer to inhibit autopolymerization of organic peroxides. It is used as an antioxidant in biodiesel. Polaroid uses it as a photographic developer in their black and white and Reclaimed Blue films.
Any trauma or lacerations Injection drug use Recent surgery Injury of mucous membranes, including hemorrhoids, rectal fissures Peripheral artery disease Cancer Alcohol use disorder Pregnancy or recent childbirth For unclear reasons, it can also infect healthy individuals without medical history or injury. NSAIDs may increase the rates of necrotizing infections by impairing the body's immune response. NSAIDs inhibit the production of prostaglandins responsible for fever, inflammation, and pain. In theory, it also prevents white blood cells from migrating to infected areas, thus increasing the risk of soft-tissue infections. Skin infections such as abscesses and ulcers can also complicate NF. A small percentage of people can also get NF when bacteria from streptococcal pharyngitis spreads through the blood. For infection of the perineum and genitals (Fournier gangrene), urinary tract infection, renal stones, and Bartholin gland abscess may also be implicated.
Freezing is an effective form of food preservation because the pathogens that cause food spoilage are either killed or do not grow very rapidly at reduced temperatures. The process is less effective in food preservation than are thermal techniques, such as boiling, because pathogens are more likely to be able to survive cold temperatures rather than hot temperatures. One of the problems surrounding the use of freezing as a method of food preservation is the danger that pathogens deactivated (but not killed) by the process will once again become active when the frozen food thaws. Foods may be preserved for several months by freezing. Long-term frozen storage requires a constant temperature of −18 °C (0 °F) or less.
=== 2014 FDA Form 483 === In December 2014 the FDA issued a Form 483 letter over concerns discovered during an inspection of its Srikakulam facility. No specific violations were mentioned in the letter.
=== Pulmonary rehabilitation === Fatigue and loss of muscular mass are common and disabling problems for patients with IPF. Pulmonary rehabilitation may alleviate the overt symptoms of IPF and improve functional status by stabilizing and/or reversing the extrapulmonary features of the disease. The number of published studies on the role of pulmonary rehabilitation in idiopathic pulmonary fibrosis is small, but most of these studies have found significant short-term improvements in functional exercise tolerance, quality of life, and dyspnea on exertion. Typical programs of rehabilitation include exercise training, nutritional modulation, occupational therapy, education and psychosocial counseling. In the late phase of disease, IPF patients tend to discontinue physical activity due to increasing dyspnea. Whenever possible, this should be discouraged.
Sources: en.wikipedia.org
Smashburger sources its ingredients from producers local to its stores, where possible. Chicago-based locations serve burgers made with Sweet Baby Ray's barbecue sauce, while Tennessee burgers use Jack Daniel's BBQ sauce, Florida locations use barbecue sauce containing orange juice, New Orleans locations have a barbecue sauce containing Barq's syrup and Utah locations serve honey barbecue. Telera rolls are used as buns in California restaurants, pretzel buns are served in Chicago restaurants, onion rolls in Minnesota restaurants and brioche in New York restaurants. In 2012, the company launched a program to partner with regional craft beer breweries to serve local beers to pair with its burgers and sandwiches. It promoted the new program with tasting events featuring bloggers and local media. In this program, each burger on Smashburger's menu is paired with a specific beer from the brewer, which is then sold in restaurant locations in that area. The partnerships caused a 30 to 50 percent increase in beer sales in stores, Ryan later said. About 15 to 20 percent of all orders now include a beer order. Among the breweries Smashburger partners with (as of 2016) are Deep Ellum Brewing Co. in Dallas, Summit Brewing Co. in Minneapolis, Sixpoint Brewery in New York, and Christian Moerlein Brewing Co. in Cincinnati.
During a 2019 analysis, Pew stated that they have yet to set an endpoint to Generation Z, but did use the year 2012 to complete their analysis. Jason Dorsey of the Center for Generational Kinetics also cites Pew Research's 1997–2012 range to define Gen Z in a 2025 article. In a 2022 article, U.S. Census economists Neil Bennett and Briana Sullivan described Generation Z as those born 1997 to 2013. Psychologists Jean Twenge and Jonathan Haidt argue that even though the concept of a social generation remains debated, there is evidence for significant differences between the different demographic cohorts. Those born between (on the cusp of) the Millennial generation and Generation Z are commonly known as Zillennials. Those born (on the cusp of) Generation Z and Generation Alpha are commonly known as Zalphas.
"DEA Schedules of Controlled Substances: Rescheduling of Hydrocodone Combination Products From Schedule III to Schedule II". Federal Register. 6 October 2014. Archived from the original on 10 August 2016. Retrieved 6 October 2014.
The problem of optimizing ET (Equation (1)) can be easily formulated as an integer linear program (ILP). One of the most powerful formulations uses binary variables to represent the presence of a rotamer and edges in the final solution, and constraints the solution to have exactly one rotamer for each residue and one pairwise interaction for each pair of residues:
Sources: en.wikipedia.org
Samidorphan (INNTooltip International Nonproprietary Name, USANTooltip United States Adopted Name) is an opioid antagonist that in the form of olanzapine/samidorphan (sold as Lybalvi) is used in the treatment of schizophrenia and bipolar disorder. Samidorphan reduces the weight gain associated with olanzapine. Samidorphan is taken by mouth. Samidorphan was under development as a standalone medication for various indications but has been discontinued. Buprenorphine/samidorphan for the treatment of major depressive disorder was rejected by the US Food and Drug Administration (FDA) due to insufficient evidence of effectiveness, but remains in preregistration as of September 2021. Development of baclofen/samidorphan has also been discontinued.
=== Dysbiosis === Disruptions in the intestinal microbiota seem to influence MASLD risk in several ways. People with MASH can have elevated levels of blood ethanol and Pseudomonadota (which produce alcohol), with dysbiosis proposed as a mechanism for this elevation. Alterations in the composition of the intestinal microbiota may influence MASLD risk in several ways. These changes appear to increase the permeability of intestinal tissue, thereby facilitating increased liver exposure to harmful substances (e.g., translocated bacteria, bacterial toxins, and inflammatory chemical signals). The increased transport of these harmful substances to the liver promotes liver inflammation, enhances nutrient and calorie absorption, and alters choline metabolism. Higher levels of intestinal bacteria that produce butyrate may be protective. Excessive macronutrient intake contributes to gut inflammation and perturbation of homeostasis, and micronutrients may also be involved. In addition to reducing weight and risk factors, lifestyle changes may prompt positive changes in the gut microbiota. In particular, diet diversity may play a role that was overlooked in animal studies, since they often compare a Western high-fat, low-diversity diet against a low-fat but higher-diversity chow. The health benefits after bariatric surgery may also involve changes in the gut microbiota by increasing gut permeablity.
==== Washing machines ==== There are instances in which silver nanoparticles and colloidal silver are used in consumer goods. Samsung for example claimed that the use of silver nanoparticles in washing machines would help to sterilize clothes and water during the washing and rinsing functions, and allow clothes to be cleaned without the need for hot water. The nanoparticles in these appliances are synthesized using electrolysis. Through electrolysis, silver is extracted from metal plates and then turned into silver nanoparticles by a reduction agent. This method avoids the drying, cleaning, and re-dispersion processes, which are generally required with alternative colloidal synthesis methods. Importantly, the electrolysis strategy also decreases the production cost of Ag nanoparticles, making these washing machines more affordable to manufacture. Samsung has described the system:
As a chemist he is known best for his work on organic synthesis, including discovery of the aldol reaction Hans-Joachim Born (1909–1987), German radiochemist who participated in the Soviet nuclear weapons programme Carl Bosch (1872–1940), German chemist, pioneer in the field of high-pressure industrial chemistry. Nobel Prize in Chemistry 1931 Octave Leopold Boudouard (1872–1923), French chemist who discovered the Boudouard reaction: combination of carbon and carbon dioxide to form carbon monoxide at high temperatures Jean-Baptiste Boussingault (1802–1887), French chemist with work in agricultural science, petroleum science and metallurgy
Since 2019, Schleip has been a professor of conservative and rehabilitative orthopaedics in the Department of Sport and Health Sciences at the Technical University of Munich, and a faculty member at the Diploma University of Applied Sciences. In 2023, he was appointed as a professor of health and psychology at the Diploma University of Applied Sciences.
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.
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.