A practical reference on Melanotan II: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-09-26 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic cyclic heptapeptide | Analogue of alpha-melanocyte-stimulating hormone |
| Common synonyms | MT-II; melanotan 2 | No internationally accepted non-proprietary name |
| Typical presentation | Lyophilised powder in a sealed vial | Often supplied alongside a separate diluent |
| Regulatory status | Unapproved therapeutic substance | Customs seizure reported in several jurisdictions |
| Reported route in use | Subcutaneous injection | Self-administered outside clinical settings |
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.
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.
Quality assessment of research-grade peptide rests mainly on reversed-phase high-performance liquid chromatography for purity and on mass spectrometry for identity confirmation. A single main peak above a stated threshold, commonly ninety-eight percent by peak area, is the usual release criterion applied by suppliers. Independent analyses commissioned by laboratories and consumer organisations have repeatedly reported discrepancies between label claims and measured content, including truncated sequences, residual trifluoroacetate, and lower-than-declared peptide mass. Those findings do not establish that every supplier is unreliable, but they indicate that purity figures printed on a vial are claims requiring verification rather than settled facts.
Regulatory treatment varies by jurisdiction and has changed over time. In several countries the peptide is handled as an unapproved prescription medicine, and import or sale for human use is restricted, while elsewhere it falls under poisons or controlled-substance schedules. Enforcement activity against online vendors has been reported in Australia, New Zealand, the United Kingdom and the United States. Scholarly writing discusses melanotan-2 chiefly as an experimental tool and as a case study in unregulated peptide supply, and its precise legal position in any given country should be checked against current national schedules.
Achondroplasia is a type of autosomal dominant genetic disorder that is the most common cause of dwarfism. It is also the most common type of non-lethal osteochondrodysplasia or skeletal dysplasia. The prevalence is approximately 1 in 25,000 births. Achondroplastic dwarfs have short stature, with an average adult height of 131 cm (4 feet, 3 inches) for males and 123 cm (4 feet, 0 inches) for females. In achondroplasia the dwarfism is readily apparent at birth. Likewise, craniofacial abnormalities in the form of macrocephaly and mid-face hypoplasia are present at birth. The previous clinical findings differentiate between achondroplasia and pseudoachondroplasia in which dwarfism is not recognizable at birth and craniofacial abnormalities are not considered a disease feature. Plain radiography plays an additional and important role in the differential diagnosis of achondroplasia.
=== American aircraft pilots === Beginning in April 2010, fluoxetine became one of four antidepressant drugs that the FAA permitted for pilots with authorization from an aviation medical examiner. The other permitted antidepressants are sertraline (Zoloft), citalopram (Celexa), and escitalopram (Lexapro). These four remain the only antidepressants permitted by FAA as of 2 December 2016. Sertraline, citalopram, and escitalopram are the only antidepressants permitted for EASA medical certification, as of January 2019.
University-based ophthalmologists in the US and Canada further refined the use of botulinum toxin as a therapeutic agent. By 1985, a scientific protocol of injection sites and dosage had been empirically determined for treatment of blepharospasm and strabismus. Side effects in treatment of this condition were deemed to be rare, mild and treatable. The beneficial effects of the injection lasted only four to six months. Thus, blepharospasm patients required re-injection two or three times a year. In 1986, Scott's micromanufacturer and distributor of Botox was no longer able to supply the drug because of an inability to obtain product liability insurance. People became desperate, as supplies of Botox were gradually consumed, forcing him to abandon people who would have been due for their next injection. For a period of four months, American blepharospasm patients had to arrange to have their injections performed by participating doctors at Canadian eye centers until the liability issues could be resolved. In December 1989, Botox was approved by the US FDA for the treatment of strabismus, blepharospasm, and hemifacial spasm in people over 12 years old. In the case of treatment of infantile esotropia in people younger than 12 years of age, several studies have yielded differing results.
Sources: en.wikipedia.org
This is given by the Michaelis–Menten constant (Km), which is the substrate concentration required for an enzyme to reach one-half its maximum reaction rate; generally, each enzyme has a characteristic KM for a given substrate. Another useful constant is kcat, also called the turnover number, which is the number of substrate molecules handled by one active site per second. The efficiency of an enzyme can be expressed in terms of kcat/Km. This is also called the specificity constant and incorporates the rate constants for all steps in the reaction up to and including the first irreversible step. Because the specificity constant reflects both affinity and catalytic ability, it is useful for comparing different enzymes against each other, or the same enzyme with different substrates. The theoretical maximum for the specificity constant is called the diffusion limit and is about 108 to 109 (M−1 s−1). At this point every collision of the enzyme with its substrate will result in catalysis, and the rate of product formation is not limited by the reaction rate but by the diffusion rate. Enzymes with this property are called catalytically perfect or kinetically perfect. Example of such enzymes are triose-phosphate isomerase, carbonic anhydrase, acetylcholinesterase, catalase, fumarase, β-lactamase, and superoxide dismutase. The turnover of such enzymes can reach several million reactions per second. But most enzymes are far from perfect: the average values of
Naloxone (Nyxoid) was approved for use in the European Union in September 2017. In the United States, some nasal naloxone are legally available without a prescription. As of 2019, officials in 29 states had issued standing orders to enable licensed pharmacists to provide naloxone to patients without the individual first visiting a prescriber. Prescribers working with harm reduction or low threshold treatment programs have also issued standing orders to enable these organizations to distribute naloxone to their clients. A standing order, also referred to as a "non-patient specific prescription" is written by a physician, nurse or other prescriber to authorize medicine distribution outside the doctor-patient relationship. In the case of naloxone, these orders are meant to facilitate naloxone distribution to people using opioids, and their family members and friends. Over 200 naloxone distribution programs utilize licensed prescribers to distribute the drug through such orders, or through the authority of pharmacists (as with California's legal provision, AB1535). Laws and policies in many US jurisdictions have been changed to allow wider distribution of naloxone. In addition to laws or regulations permitting distribution of medicine to at-risk individuals and families, some 36 states have passed laws that provide naloxone prescribers with immunity against both civil and criminal liabilities.
== Medical uses == Trilaciclib is indicated to reduce the frequency of chemotherapy-induced bone marrow suppression in adults receiving certain types of chemotherapy for extensive-stage (when the cancer has spread beyond the lungs) small cell lung cancer.
Sources: en.wikipedia.org
=== Cleaning === Dust and dirt are removed from herbarium sheets by using a smoke sponge. Conservators gently rub the place where the dirt is and then softly remove any excess with a fine brush. Care must be taken by conservators when dealing with older prepared specimens that may have traces of toxic chemicals. Making use of personal protective equipment by professionals can reduce the risk of exposure or harm due to dangerous materials.
== Professional contribution == Kalra established Bharti Hospital in Karnal, which offers clinical care, research, training, and education in endocrinology. As executive editor (2011–15), he played a role in strengthening the Indian Journal of Endocrinology and Metabolism (IJEM), which became recognised as India's second-highest-ranked scientific journal according to Google Metrics. He also serves as executive editor of Thyroid Research and Practice and associate editor of Diabetic Medicine (UK). In addition, he is an international advisory board member for several journals, including US Endocrinology, the Sri Lankan Journal of Diabetes, Endocrinology and Metabolism (SLJDEM), the Journal of Pakistan Medical Association, and the Journal of Diabetes and Endocrinology Association of Nepal (JDEAN). As a founder member and past president, Kalra has contributed to the establishment and growth of the South Asian Federation of Endocrine Societies (SAFES). His contributions have been recognised in neighbouring countries, and he has been awarded Fellowship and Life Membership of the Sri Lanka College of Endocrinologists (SLCE), as well as life membership of the Pakistan Endocrine Society (PES).
1925: British-American astronomer and astrophysicist Cecilia Payne-Gaposchkin established that hydrogen is the most common element in stars, and thus the most abundant element in the universe. 1926: American scientist Katharine Burr Blodgett became the first woman to earn a PhD in physics at the University of Cambridge, under the supervision of Sir Ernest Rutherford. 1927: Japanese biologist and cytologist Kono Yasui became the first Japanese woman to earn a doctorate in science, studying at the Tokyo Imperial University and completing her thesis on "Studies on the structure of lignite, brown coal, and bituminous coal in Japan". 1927: Bohumila Bednářová, the first Czech woman to become professionally involved in astronomy, co-founds the Prague Observatory. 1928: American microbiologist Alice Evans became the first woman elected president of the Society of American Bacteriologists. 1928: Helen Battle became the first woman to earn a PhD in marine biology in Canada. 1928: British biologist Kathleen Carpenter published the first English-language textbook devoted to freshwater ecology: Life in Inland Waters. 1929: American botanist Margaret Clay Ferguson became the first female president of the Botanical Society of America. 1929: Scottish-Nigerian physician Agnes Yewande Savage became the first West African woman to graduate from medical school, obtaining her degree at the University of Edinburgh Medical School.
==== Studio albums ==== American Drift (2015, Blueberry Recordings) Elysia Crampton Presents: Demon City (2016, Break World Records) Spots y Escupitajo (2017, The Vinyl Factory) Elysia Crampton (2018, Break World Records) Orcorara 2010 (2020, PAN)
Sources: en.wikipedia.org
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.
It was developed in the 1980s by researchers investigating analogues of alpha-melanocyte-stimulating hormone for pigmentation and related endpoints. Early work included small human studies during the 1990s. Development did not progress to licensing, and the compound remained a research and grey-market item.
Peptides are prone to truncation, oxidation and aggregation during synthesis and handling. Without independent testing, a buyer cannot confirm the identity or the content of a vial. Analytical surveys of unapproved peptide products have repeatedly found discrepancies between label claims and measured composition.
Only a small number of early-stage human studies have been reported, and most were limited in size and duration. No large late-stage program has established a general efficacy or safety profile. The evidence base is therefore thin compared with approved medicines.