The short version of regulatory status fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-03-25 and is reviewed periodically as new material appears.
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.
Because the substance circulates mainly through informal markets, verification is a recurring theme in technical discussion. Independent analyses have found that labeled content and actual content can diverge, and that purity varies between samples. Analytical laboratories use reversed-phase chromatography to separate components and mass spectrometry to confirm identity. Isotope-labeled internal standards improve quantification in complex matrices. Such methods describe what a sample contains but say nothing about its sterility, lawful status, or suitability for any use. Open questions remain about how consistently testing is applied across the supply chain.
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.
Outside regulated medicine, melanotan II circulates through online vendors as a research chemical, often marketed for tanning. Products sold this way vary widely in purity, concentration, and labeling accuracy, and independent testing has documented discrepancies. Published reports describe both pigment effects and adverse reactions, including nausea, flushing, and darkening of existing moles. Long-term safety data are sparse, and no large controlled trial has established a risk profile. Questions about cumulative effects on melanocytes remain unresolved in the literature.
Melanotan II is a synthetic peptide analog modeled on alpha-melanocyte-stimulating hormone, a naturally occurring signaling peptide involved in pigmentation. Its structure is a cyclic heptapeptide containing two non-natural substitutions, norleucine at position four and D-phenylalanine at position seven. These modifications resist enzymatic breakdown and extend the molecule's activity relative to the native hormone. The compound binds melanocortin receptors and is studied mainly as a pharmacological tool rather than a therapeutic product. It has never received approval as a medicine in any major jurisdiction.
The compound was developed in the late 1980s and 1990s by academic researchers investigating photoprotection. The rationale held that stimulating melanin production might reduce ultraviolet damage to skin and lower skin cancer risk. Early work examined receptor binding, pigment response, and short-term tolerability in small studies. That program did not produce an approved drug, and formal development stalled after early-phase trials. Whether induced pigmentation confers meaningful photoprotection remains an open question.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved as a medicine | No marketing authorization in major jurisdictions |
| Scheduling example | Prescription-only supply in some countries | Handled as an unlicensed medicine where restricted |
| Sports classification | Prohibited peptide | Appears on anti-doping prohibited lists |
| Reported presentation | Lyophilized vial | Nominal content varies between vendors |
| Detection approach | Liquid chromatography–tandem mass spectrometry | Used in anti-doping and forensic testing |
Routine characterisation relies on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometres, using a C18 column and a water-acetonitrile gradient containing trifluoroacetic acid. Electrospray ionisation mass spectrometry confirms the expected molecular mass and can reveal truncated or oxidised by-products that co-elute poorly. Sequence and stereochemistry require additional work, such as peptide mapping or amino acid analysis, because a chromatographic purity figure alone does not distinguish a diastereomer from the target peptide. Independent testing of research-grade material frequently shows measured content below the stated label, so a certificate of analysis is best read together with the method that produced it.
Melanotan-2 is handled in the laboratory as a lyophilised powder that dissolves readily in water, dimethyl sulfoxide and dimethylformamide, with limited solubility in ethanol. Stock solutions prepared in an organic solvent often precipitate when diluted into aqueous buffer, so gradual dilution with mixing is standard practice. The peptide carries a tryptophan residue and a histidine residue, both sensitive to oxidation and to alkaline conditions. Working solutions are therefore kept near neutral to slightly acidic pH, protected from light, and consumed within the same working session whenever that is practical.
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.
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.
Regulatory status differs by country, and in many places supplying the compound for human consumption is unlawful. Vendors frequently label material as intended for research use only, a designation that shifts stated purpose but does not create a legal pathway for personal use. Certificates of analysis accompanying such products vary widely in detail and provenance. Third-party testing exists but is voluntary, and results are rarely linked to a specific lot in a publicly verifiable way.
Identity testing for a synthetic peptide relies on several complementary methods. Reversed-phase high-performance liquid chromatography separates the target from related impurities and reports purity as a percentage of total peak area. Mass spectrometry confirms molecular mass and can reveal deletions or truncations. Amino acid analysis and peptide mapping provide sequence-level confirmation, while counter-ion content and residual solvents are measured separately. A purity figure alone does not establish identity, so a complete dataset combines chromatographic and spectrometric evidence.
Lyophilized peptide powder is generally stored frozen, protected from light and moisture. Tryptophan residues are susceptible to oxidation, and the lactam bridge can hydrolyze under strongly acidic or basic conditions. Solutions prepared for laboratory work degrade faster than dry powder, and repeated freeze-thaw cycles accelerate loss. Common practice is to aliquot solutions before freezing and to avoid alkaline buffers. Reported stability windows vary with concentration, buffer, and temperature, so exact shelf lives are method-specific rather than universal.
== Further reading == Craigie, W.A.; Bradley, H. (1914). "Realgar". In Sir James, A.H. Murray (ed.). A New English Dictionary on Historical Principles. Clarendon Press at Oxford. p. 202 – via archive.org. William Mesny (1899). Mesny's Chinese Miscellany. A Text Book of Notes on China and the Chinese. Vol. III. Shanghai. p. 251. William Mesny (1905). Mesny's Chinese Miscellany. A Text Book of Notes on China and the Chinese. Vol. IV. Shanghai. pp. 425–426.
This tunnel contains a set of tight binding pockets such that each side chain of the substrate peptide (P6 to P1') is bound in a complementary site (S6 to S1'). In particular, peptide side chain P6-Glu contacts a network of three hydrogen bonds; P5-Asn points into the solvent, making no specific interactions (hence the absence of substrate consensus at this position); P4-Leu is buried in a hydrophobic pocket; P3-Tyr is held in a hydrophobic pocket with a short hydrogen bond at the end; P2-Phe is also surrounded by hydrophobes including the face of the triad histidine; P1-Gln forms four hydrogen bonds; and P1'-Ser is only partly enclosed in a shallow hydrophobic groove.
Professor at the University of Groningen. Rachel Mamlok-Naaman, Israeli chemist, specialized in chemistry education Corine Mathonière, French materials chemist studying molecular magnetism, spin crossover molecules, and coordination chemistry Catherine J. Murphy, American chemist Nga Lee (Sally) Ng, atmospheric chemist studying particulates and their effects on air quality, climate, and human health Sarah O'Connor, American plant synthetic biologist working in England Kimberly Prather, American atmospheric chemist whose research contributed to understanding of atmospheric aerosols and their impact on air quality, climate, and human health Gillian Reid, British inorganic chemist. President elect (2020-present) and present (2022-present) of the Royal Society of Chemistry. Professor at the University of Southampton. Sarah E Reisman, American organic chemist Magdalena Titirici, materials chemist focusing on sustainable materials for energy applications. Professor at Imperial College London. Claudia Turro, American inorganic chemist who studies light-initiated reactions of metal complexes with application to disease treatment and solar energy conversion. Seble Wagaw, American process chemist and pharma exec Marcey Lynn Waters, American chemical biologist and supramolecular chemist Jenny Y Yang, American chemist and clean energy researcher at UCI Wendy Young, American medicinal chemist and pharmaceutical executive. Chair of ACS Medicinal Chemistry Division (2017). Jaqueline Kiplinger, American chemist working at the Los Alamos National Laboratory
==== Season 1 ==== The following table represents viewership data for each episode's airing on The CW, as DC Universe did not release viewership information. The pilot episode was tied for the second-best series debut on The CW for the 2019–20 television season with Nancy Drew after Batwoman, and was the best summer series premiere on the network since Whose Line Is It Anyway? season nine in 2013. Through the first seven episodes of the season, Stargirl was averaging a 0.2 rating for adults 18–49 and close to 1 million initial viewers per episode, which was "on par" with The CW's Arrowverse series.
=== Phenolics === E. globulus bark contains quinic, dihydroxyphenylacetic and caffeic acids, bis(hexahydroxydiphenoyl (HHDP))-glucose, galloyl-bis(HHDP)-glucose, galloyl-HHDP-glucose, isorhamentin-hexoside, quercetin-hexoside, methylellagic acid (EA)-pentose conjugate, myricetin-rhamnoside, isorhamnetin-rhamnoside, mearnsetin, phloridzin, mearnsetin-hexoside, luteolin and a proanthocyanidin B-type dimer, digalloylglucose and catechin. The hydrolyzable tannins tellimagrandin I, eucalbanin C, 2-O-digalloyl-1,3,4-tri-O-galloyl-β-D-glucose, 6-O-digalloyl-1,2,3-tri-O-galloyl-β-D-glucose, as well as gallic acid and (+)-catechin can also be isolated. Tricetin is a rare flavone aglycone found in the pollen of members of the Myrtaceae, subfamily Leptospermoideae, such as E. globulus.
Sources: en.wikipedia.org
==== Biomarkers ==== Consuming trans fats has been shown to increase the risk of coronary artery disease in part by raising levels of low-density lipoprotein (LDL, often termed "bad cholesterol"), lowering levels of high-density lipoprotein (HDL, often termed "good cholesterol"), increasing triglycerides in the bloodstream and promoting systemic inflammation. Trans fat has been found to act like saturated in raising the blood level of LDL ("bad cholesterol"); but, unlike saturated fat, it also decreases levels of HDL ("good cholesterol"). The net increase in LDL/HDL ratio with trans fat, a widely accepted indicator of risk for coronary artery disease, is approximately double that due to saturated fat. One randomized crossover study published in 2003 comparing the effect of eating a meal on blood lipids of (relatively) cis and trans-fat-rich meals showed that cholesteryl ester transfer (CET) was 28% higher after the trans meal than after the cis meal and that lipoprotein concentrations were enriched in apolipoprotein(a) after the trans meals. The cytokine test is a potentially more reliable indicator of CAD risk, although is still being studied. A study of over 700 nurses showed that those in the highest quartile of trans fat consumption had blood levels of C-reactive protein (CRP) that were 73% higher than those in the lowest quartile.
biosynthesis from the sulfur amino acids (e.g., cysteine); active uptake by a taurine transporter; and the extent of its release from cells by a "volume-sensitive leak pathway". Taurine is a major constituent of bile, and can be found in the large intestine. Its concentrations in land plants are low or undetectable, but up to a substantial wet weight has been found in algae.
Conformations are the same in solution and when adsorbed. Diastereomers bind to surfaces (silica gel in normal phase chromatography) mainly with hydrogen bonding. Significant resolution of diastereomers is only expected when molecules can adsorb to silica through two contact points (two hydrogen bonds). This interaction can be perturbed by substituents. Diastereomers with bulky substituents on the alpha carbon (R2) and on the nitrogen (R1) can shield the hydrogen bonding with the surface, thus the molecule will be eluted before similar molecules with smaller substituents. Helmchen's postulates have been proven to be applicable to other functional groups such as: carbamates, esters, and epoxides.
=== Filming === Initial film shooting started in February 1992 through to April 1992. Film producers were reluctant to release too much information about the film to the media, particularly the ending, while photograph releases to print media were limited. Various locations were used including Mendocino County where shooting took place from March 29 to April 2. A purpose-built set was built at the Stornetta Ranch, near the lighthouse in Point Arena. Although the film made use of real rain for some exterior scenes, artificial rainmakers were also used to maintain a consistency in downpours for the cameras. Curtis had never met Gibson prior to working with him on the film. During an interview, she notes the cast members would frequently play pranks on each other but that "it was a fun set, this was the fun place to be." It was the first film where Curtis had played a mother. Gibson had to spend 2 hours each day to have the latex aging make-up applied to make him appear as an 80-year-old. During filming, he slipped and dislocated his shoulder, but did not immediately realize the severity of the injury. After becoming dizzy and struggling to remember his lines, a chiropractor reset his shoulder. Gibson later remarked that forgetting his lines troubled him more than the pain. In the scene where Wood sings "You Are My Sunshine" to the girl in the tree house, it was originally going to be a different song which according to director Steve Miner, would have been very expensive to use, whereas the song used in the film was already freely available in the public domain.
The osmotic-controlled release oral delivery system (OROS) is an advanced controlled release oral drug delivery system in the form of a rigid tablet with a semi-permeable outer membrane and one or more small laser drilled holes in it. As the tablet passes through the body, water is absorbed through the semipermeable membrane via osmosis, and the resulting osmotic pressure is used to push the active drug through the laser drilled opening(s) in the tablet and into the gastrointestinal tract. OROS is a trademarked name owned by ALZA Corporation, which pioneered the use of osmotic pumps for oral drug delivery.
Sources: en.wikipedia.org
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.
The peptide is listed as prohibited in competitive sport, so laboratories develop detection methods and monitor for its presence. Its appearance in enforcement reports reflects that classification rather than any approved athletic use. Analytical work in this area focuses on identifying the molecule and its breakdown products in biological samples.
Chromatographic separation combined with mass spectrometry identifies the peptide and estimates its amount in a sample. Testing can confirm whether the expected molecule is present and at what concentration. It cannot establish how a product was manufactured or whether it meets any purity standard.
It is a synthetic cyclic peptide designed as an analog of alpha-melanocyte-stimulating hormone. It acts on melanocortin receptors and is best known from research into pigmentation. It is not an approved pharmaceutical product.