Everything below concerns reversed-phase HPLC. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-08-01. Where a claim depends on a specific study, the study is described rather than over-claimed.
Melanotan-2 is a synthetic linear peptide built from seven amino acids arranged in a short chain. Its sequence is commonly written as Ac-Nle-Asp-His-D-Phe-Arg-Trp-Lys-NH2, which includes a modified N-terminus and an amidated C-terminus. The molecule belongs to the melanocortin family and acts as a receptor agonist. Structural features such as the D-phenylalanine residue and the Nle substitution are associated with increased stability against enzymatic degradation relative to the natural parent peptide.
The compound emerged from research programs in the 1980s that examined analogues of alpha-melanocyte-stimulating hormone for pigmentation and photoprotection. Investigators modified the native sequence to extend activity duration and potency. A related analogue, afamelanotide, was developed within the same broad line of inquiry and eventually gained approval in certain jurisdictions for a rare light-sensitivity condition. Melanotan-2 itself did not progress through the same regulatory route and has no approved therapeutic indication.
Identity and purity are assessed with chromatographic and mass spectrometric techniques. Reversed-phase high-performance liquid chromatography separates the target peptide from related impurities and degradation products, and the resulting retention time is compared against a reference standard. Mass spectrometry, often coupled to liquid chromatography, confirms molecular mass. Amino acid analysis or peptide mapping can provide additional sequence-level confirmation when required. Results are only as reliable as the reference materials used alongside them.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C50H69N15O9 | Free base; salt forms differ |
| Molecular weight | Approximately 1024 g/mol | Calculated for the free base |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water and polar solvents | Poorly soluble in non-polar solvents |
| Typical storage | -20 degrees Celsius, dry, protected from light | Refers to the solid form |
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.
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.
Anderson BM, Lang CA (1966). "Nicotinamide-adenine dinucleotide pyrophosphatase in the growing and aging mosquito". Biochem. J. 101 (2): 392–6. doi:10.1042/bj1010392. PMC 1270119. PMID 4381708. Nakajima Y, Fukunaga N, Sasaki S, Usami S (1973). "Purification and properties of NADP pyrophosphatase from Proteus vulgaris". Biochim. Biophys. Acta. 293 (1): 242–55. doi:10.1016/0005-2744(73)90397-5. PMID 4405504.
Whereas chaotropic compounds such as ethanol interfere with non-covalent intramolecular forces as outlined above, salts can have chaotropic properties by shielding charges and preventing the stabilization of salt bridges. Hydrogen bonding is stronger in non-polar media, so salts, which increase the chemical polarity of the solvent, can also destabilize hydrogen bonding. Mechanistically this is because there are insufficient water molecules to effectively solvate the ions. This can result in ion-dipole interactions between the salts and hydrogen bonding species which are more favorable than normal hydrogen bonds. Common chaotropic agents include n-butanol, ethanol, guanidinium chloride, lithium perchlorate, lithium acetate, magnesium chloride, phenol, 2-propanol, sodium dodecyl sulfate, thiourea, and urea.
History of radiochemistry – history of the chemistry of radioactive materials, where radioactive isotopes of elements are used to study the properties and chemical reactions of non-radioactive isotopes (often within radiochemistry the absence of radioactivity leads to a substance being described as being inactive as the isotopes are stable). History of organic chemistry – history of the study of the structure, properties, composition, reactions, and preparation (by synthesis or by other means) of carbon-based compounds, hydrocarbons, and their derivatives. History of petrochemistry – history of the branch of chemistry that studies the transformation of crude oil (petroleum) and natural gas into useful products or raw materials. History of organometallic chemistry – history of the study of chemical compounds containing bonds between carbon and a metal. History of photochemistry – history of the study of chemical reactions that proceed with the absorption of light by atoms or molecules. History of physical chemistry – history of the study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of physical laws and concepts. History of chemical kinetics – history of the study of rates of chemical processes. History of chemical thermodynamics – history of the study of the interrelation of heat and work with chemical reactions or with physical changes of state within the confines of the laws of thermodynamics.
=== July === 1 July – Balmoral Castle opens to the public for tours for the first time, with daily tours running until 4 August. Steve Carson is to step down as Head of Multi-Platform Commissioning at BBC Scotland in September, in order to take up a senior role at Irish broadcaster RTÉ. 2 July – After rejecting a pay offer in May, waste and recycling staff belonging to Unite in half of Scotland's councils vote to strike. 3 July – Queen Camilla and Prince Edward are formally appointed to the Order of the Thistle at a ceremony in Edinburgh. Moray Council is ordered to pay £346,000 in compensation to a foster family who were wrongly accused of "sexual impropriety" involving children they fostered during the 2010s. 5 July – 2024 United Kingdom general election in Scotland: The SNP suffers heavy losses, going from 48 seats to just nine. With 56 of the 57 seats contested in Scotland declared, Labour win 37, the SNP win nine, while the Conservatives and Liberal Democrats each win five. Starmer ministry: The incoming Labour prime minister Keir Starmer appoints Ian Murray as Secretary of State for Scotland. 6 June – 2024 United Kingdom general election in Scotland: Inverness, Skye and West Ross-shire becomes the final constituency to declare its election results, and sees the number of Liberal Democrat MPs rise to 6 in Scotland after they defeat the SNP to win the seat.
Sources: en.wikipedia.org
Oligopeptide P11-4 is a synthetic, pH controlled self-assembling peptide used for biomimetic mineralization e.g. for enamel regeneration or as an oral care agent. P11-4 (INCI name Oligopeptide 104) consists of the natural occurring amino acids Glutamine, Glutamic acid, Phenylalanine, Tryptophan and Arginine. The resulting higher molecular structure has a high affinity to tooth mineral. P11-4 has been developed and patented by The University of Leeds (UK). The Swiss company Credentis has licensed the peptide technology and markets it under the trade names including CUROLOX, REGENAMEL, and EMOFLUOR. They offer three products with this technology. As of June 2016 in Switzerland products are available with new Brand names from Dr. Wild & Co AG.
=== Performance === Early onset of fatigue Decreased aerobic capacity (VO2 max) Poor physical performance Inability to complete workouts Delayed recovery Overtraining can affect the athlete's athletic ability and other areas of life, such as performance in studies or the workforce. An overtrained athlete who is suffering from physical and/or psychological distress could also have trouble socializing with friends and family, studying for an exam, or preparing for work.
1993/2046) Police (Amendment) (No.3) Regulations 1993 (S.I. 1993/2047) Goods Vehicles (Plating and Testing) (Amendment) Regulations 1993 (S.I. 1993/2048) National Health Service (Travelling Expenses and Remission of Charges) (Scotland) Amendment (No.2) Regulations 1993 (S.I. 1993/2049) Prisoners and Criminal Proceedings (Scotland) Act 1993 Commencement, Transitional Provisions and Savings Order 1993 (S.I. 1993/2050) A34 Trunk Road (A34/M4 Junction 13 Improvement) Line and Slip Roads Order 1993 (S.I. 1993/2056) A6 Trunk Road (Great Glen Bypass) Order 1993 (S.I. 1993/2057) A6 Trunk Road (Great Glen Bypass) (Detrunking) Order 1993 (S.I. 1993/2058) Easington Lagoons (Area of Special Protection) (No.2) Order 1993 (S.I. 1993/2059) Capacity Serving Measures (Intoxicating Liquor) (Amendment) Regulations 1993 (S.I. 1993/2060) Enforcement of Road Traffic Debts (Certificated Bailiffs) Regulations 1993 (S.I. 1993/2072) Enforcement of Road Traffic Debts Order 1993 (S.I. 1993/2073) Education (School Performance Information) (England) (No. 2) Regulations 1993 (S.I. 1993/2077) Housing Renovation etc. Grants (Prescribed Forms and Particulars) (Welsh Forms and Particulars) (Amendment) (No. 2) Regulations 1993 (S.I. 1993/2078) Lerwick Harbour Revision Order 1993 (S.I. 1993/2087) Safety of Sports Grounds (Designation) Order 1993 (S.I. 1993/2090) Essex and Greater London (County Boundaries) Order 1993 (S.I. 1993/2091) Social Security (Contributions) Amendment (No. 6) Regulations 1993 (S.I. 1993/2094) Local Authorities (Goods and Services) (Public Bodies) Order 1993 (S.I.
3 Ca(OH)2 + 6 S → 2 CaS2 + CaS2O3 + 3 H2O where the S2−2 species corresponds to the disulfide anion −S−S− (with a covalent bond between the two sulfur atoms), also present in pyrite (FeS2), a Fe(II) disulfide mineral. They also successfully controlled this reaction to achieve the conversion of elemental sulfur into a quasi-pure solution of calcium thiosulfate.
Cocaine is sometimes used in otorhinolaryngology as a topical anesthetic and vasoconstrictor to help control pain and bleeding during surgery of the nose, mouth, throat, or lacrimal duct. It is also used for topical airway anaesthesia for procedures such as awake fibreoptic bronchoscopy or intubation. Although some absorption and systemic effects may occur, the use of cocaine as a topical anesthetic and vasoconstrictor is generally safe, rarely causing cardiovascular toxicity, glaucoma, and pupil dilation. Occasionally, cocaine is mixed with adrenaline and sodium bicarbonate and used topically for surgery, a formulation called Moffett's solution. It is occasionally used in surgeries involving the pharynx or nasopharynx to reduce pain, bleeding, and vocal cord spasm. Nasal solution cocaine hydrochloride (Goprelto), an ester used for intranasal application, was approved for medical use in the United States in December 2017, and is indicated for the introduction of topical anesthesia of the mucous membranes for diagnostic procedures and surgeries on or through the nasal cavities of adults. Cocaine hydrochloride (Numbrino) was approved for medical use in the United States in January 2020. Headache and epistaxis are the most frequently reported adverse reactions with Goprelto, while hypertension and tachycardia-including sinus tachycardia-are most common with Numbrino.
Sources: en.wikipedia.org
No. Melanotan-2 is manufactured synthetically. The naturally occurring peptide in the same family is alpha-melanocyte-stimulating hormone, which the body produces as part of normal endocrine and neural signalling.
Both are synthetic analogues derived from the same parent hormone. Reference descriptions usually characterise afamelanotide as more selective for the MC1R subtype, whereas melanotan-2 is reported to interact with a wider range of melanocortin receptors.
Early studies explored melanocortin signalling and pigmentation, which later led to informal use of the label tanning peptide. That label is not a regulatory category and does not imply approved status for any purpose.
Laboratory confirmation typically combines retention time matching on a chromatographic system with mass measurement. A reference standard of known identity is needed for a meaningful comparison. Sequence-level techniques can add further confirmation.