A practical reference on afamelanotide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-02-05 and is reviewed periodically as new material appears.
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 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.
Identity testing for a cyclic peptide of this size usually relies on reversed-phase high-performance liquid chromatography coupled to mass spectrometry. The mass spectrum confirms molecular weight, while the chromatographic trace indicates the proportion of related impurities. Tandem mass spectrometry can provide sequence-level information when fragmentation data are compared against a reference standard. Nuclear magnetic resonance is sometimes used to confirm the lactam bridge, although it requires more material and greater operator expertise than routine chromatographic methods.
Lyophilised peptide powder is comparatively stable when kept dry, cold and protected from light. Once dissolved, the molecule is exposed to hydrolysis, oxidation and microbial growth, and degradation accelerates at higher temperatures and in alkaline solution. Repeated freeze-thaw cycles concentrate solutes and promote aggregation. Handling guidance for research peptides commonly clusters around freezer temperatures for powder and short refrigerated use for reconstituted solutions, with pH control and sterile technique applied throughout.
Verification of a purchased sample requires documentation linking a batch to a certificate of analysis, and that document should be read for the methods used rather than the headline purity figure. A single chromatographic percentage does not establish identity. Independent laboratories can perform identity and content assays, but no such test establishes that a product is suitable for human use. Claims about efficacy rest largely on small, early studies rather than on replicated controlled trials, and that gap remains open.
| 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 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.
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.
The peer-reviewed record is dominated by small early-phase studies, case reports and pharmacovigilance summaries rather than large randomised trials. Papers typically examine tanning response, receptor selectivity or patterns of reported adverse events. Many note that participants obtained the peptide outside a clinical setting, which limits verification of composition and administered amount. Reported events vary widely, and causality is frequently unclear because the identity and purity of self-sourced material are unknown. Open questions include whether repeated melanocortin receptor stimulation produces cumulative effects, and how often label claims match actual content.
Identification in laboratories relies on reversed-phase liquid chromatography coupled with tandem mass spectrometry, with product-ion spectra compared against a certified reference standard. High-resolution mass spectrometry supplies accurate mass confirmation, and peptide mapping after enzymatic digestion separates melanotan II from closely related analogues. Quantitation of seized material is complicated by unknown counter-ions and residual trifluoroacetate left from purification. Immunoassays raised against alpha-melanocyte-stimulating hormone can cross-react, so chromatographic confirmation is normally required. Urinary detection windows are short, and reported limits of detection differ substantially between laboratories.
In 1929, the country was renamed to Yugoslavia and the football association became Fudbalski savez Jugoslavije and ordered to move its headquarters from Zagreb to Belgrade. The national team participated at the 1930 FIFA World Cup, finishing in fourth place. In its first ever World Cup match in Montevideo's Parque Central, Yugoslavia managed a famous 2–1 win versus mighty Brazil, with the following starting eleven representing the country: Milovan Jakšić, Branislav Sekulić, Aleksandar Tirnanić, Milutin Ivković, Ivica Bek, Momčilo Đokić, Blagoje Marjanović, Milorad Arsenijević, Đorđe Vujadinović, Dragoslav Mihajlović, and Ljubiša Stefanović. The team was the youngest squad at the inaugural World Cup at an average age of just under 22 years old, and became quite popular among the Uruguayan public, who dubbed them "Los Ichachos". The national team consisted of players based in Serbian football clubs, while the Zagreb Subassociation forbid players from Croatian clubs, some of whom were regulars in the national team until then, to play in the World Cup due to the relocation of football association's headquarters from Zagreb to Belgrade.
=== Catabolism === Methionine is converted to S-adenosylmethionine (rSAM) by (1) methionine adenosyltransferase. rSAM serves as a methyl donor in many (2) methyltransferase reactions, and is converted to S-adenosylhomocysteine (SAH). (3) Adenosylhomocysteinase cysteine.
== Covalently modulated enzymes == Here, the active and inactive form of the enzymes are altered due to covalent modification of their structures which is catalysed by other enzymes. This type of regulation consists of the addition or elimination of some molecules which can be attached to the enzyme protein. The most important groups that work as modifiers are phosphate, methyl, uridine, adenine and adenosine diphosphate ribosyl. These groups are joined to or eliminated from the protein by other enzymes. The most remarkable covalent modification is phosphorylation. Serine, Threonine and Tyrosine are common amino acids that participate in covalent modifications and are used to control enzyme’s catalytic activities. Kinase and phosphatases are commonly known enzymes that affect these modifications, which result in shifting of conformational states of the binding affinity to substrate.
Sources: en.wikipedia.org
II. Full-thickness defects Full-thickness nasal defects are in three types: (i) wounds to the skin and to the soft tissues, featuring either exposed bone or exposed cartilage, or both; (ii) wounds extending through the nasal skeleton; and (iii) wounds traversing all three nasal layers: skin, muscle, and the osseo-cartilaginous framework. Based upon the dimensions (length, width, depth) and topographic locale of the wound and the number of missing nasal-tissue layers, the surgeon determines the rhinoplastic technique for correcting a full-thickness defect; each of the aesthetic nasal subunits is considered separately and in combination.
== Problems == Problems with the electrical systems in the Warrior IFV have caused the weapon to fire without warning several times, resulting in the army issuing a safety notice. In at least one incident, this has resulted in injury to a British soldier and in others injuries to civilians. The MoD denied the problem initially. Additionally, the Challenger 2 mounting of the weapon cannot be accurately aimed using the main sight below a minimum range of 200 meters, which has led to at least one death from "friendly fire".
In 2009, the first to obtain FDA approval for topical DMSO usage was PENNSAID, which contains diclofenac in a carrier with 45.5% DMSO Each 1 mL of TDiclo contains 16.05 mg diclofenac sodium. TDiclo solution also contains 45.5% dimethyl sulfoxide (DMSO) vehicle, which can result in enhanced penetration of active drug through the skin. The most common adverse event reported was dry skin at the application site (25.3% of patients), followed by contact dermatitis (13.0%)In interventional radiology, DMSO is used as a solvent for ethylene vinyl alcohol in the Onyx liquid embolic agent, which is used in embolization, the therapeutic occlusion of blood vessels. In cryobiology DMSO has been used as a cryoprotectant and is still an important constituent of cryoprotectant vitrification mixtures used to preserve organs, tissues, and cell suspensions. Without it, up to 90% of frozen cells will become inactive. It is particularly important in the freezing and long-term storage of embryonic stem cells and hematopoietic stem cells, which are often frozen in a mixture of 10% DMSO, a freezing medium, and 30% fetal bovine serum. In the cryogenic freezing of heteroploid cell lines (MDCK, VERO, etc.) a mixture of 10% DMSO with 90% EMEM (70% EMEM + 30% fetal bovine serum + antibiotic mixture) is used. As part of an autologous bone marrow transplant the DMSO is re-infused along with the patient's own hematopoietic stem cells. DMSO is metabolized by disproportionation to dimethyl sulfide and dimethyl sulfone. It is subject to renal and pulmonary excretion.
Sources: en.wikipedia.org
The United States military began executing airstrikes on vessels in the Caribbean Sea in September 2025, described by the administration of President Donald Trump as part of an effort to fight the flow of illicit drugs from Latin America to the US. In October, the strikes expanded to include vessels in the Eastern Pacific Ocean. The Trump administration has alleged, without producing public evidence, that the vessels were operated by groups it designated as narcoterrorists, including the Venezuelan organization Tren de Aragua and the Colombian far-left guerilla group National Liberation Army. As part of what was later unveiled as Operation Southern Spear, the US began deploying Navy warships and personnel to the Caribbean in mid-August. Trump announced on 2 September that the US Navy had carried out the first airstrike in the Caribbean on a boat from Venezuela, killing all 11 people aboard; he released a video of the incident, which Venezuelan sources said had occurred on 1 September. US officials said that this was a military operation against drug cartels in Latin America and that these military operations would continue. As of 19 September 2026, at least 234 people had been killed (including 17 who are missing and presumed dead) in at least 78 strikes on over 79 vessels and the US had made its first strike on a land target within Venezuela. On 12 June, Niño Guerrero, leader of Tren de Aragua, was killed in joint operation with the post-Maduro Venezuelan government.
An ion trap mass spectrometer may incorporate a Penning trap (Fourier-transform ion cyclotron resonance), Paul trap or the Kingdon trap. The Orbitrap, introduced in 2005, is based on the Kingdon trap. Other types of mass spectrometers may also use a linear quadrupole ion trap as a selective mass filter.
The Ministry of the Interior stripped the Communist Party of Ukraine, the Communist Party of Ukraine (renewed), and the Communist Party of Workers and Peasants of their right to participate in elections and stated it was continuing the court actions that started in July 2014 to end the registration of communist parties in Ukraine. By 16 December 2015, these three parties had been banned in Ukraine; the Communist Party of Ukraine appealed the ban to the European Court of Human Rights.
=== March === March 2, 2010: Canada The economy is rocketing further away from recession, increasing the chances that the Bank of Canada will lift borrowing costs more aggressively than expected later this year. Economic growth surged an annualized 5% in the fourth quarter, providing the clearest sign yet that a broad-based recovery is taking firm hold. It was the fastest annualized quarterly growth since 2000, and the first solidly positive quarter since the economy entered recession in 2008 amid a global pullback brought on by the 2008 financial crisis. The fourth-quarter surge was fuelled by everything from a strong housing sector and healthy consumer spending to a surprise turnaround for net trade as the country's exports grew at almost double the pace of imports, according to Statistics Canada.
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.
Mass spectrometry combined with liquid chromatography provides both molecular weight confirmation and a measure of related impurities. Tandem mass spectrometry adds sequence information. A purity percentage reported without a mass measurement does not confirm what the material is.