The short version of alpha-MSH fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-01-24. Anything still debated is marked as such rather than presented as settled.
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.
Melanocortin receptors comprise five subtypes with distinct tissue distributions and functions. Melanotan-2 is described in the literature as a non-selective agonist that engages several of these subtypes, including MC1R, MC3R, MC4R, and MC5R. MC1R is the subtype most directly linked to melanin production in skin cells. Because the compound is not subtype-selective, its observed effects in experimental settings are generally attributed to activity across multiple receptor pathways rather than to a single target.
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.
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.
| 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 |
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.
Solid peptide kept dry at minus twenty degrees Celsius, shielded from light and moisture, is generally considered stable for extended periods. Solutions are divided into single-use aliquots and held at minus twenty or minus eighty degrees Celsius, because repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. Hydrolysis of the backbone and oxidation of tryptophan are the principal degradation routes in aqueous solution, and both accelerate at ambient temperature. Hygroscopic uptake after a vial is opened can also shift the actual mass weighed, which affects any concentration calculated from it.
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.
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.
== Awards == Faculty Volunteer Service Award, University of Arkansas Outstanding Service Award, Veterans Association (1989-2005) Distinguished Faculty Award, University of Arkansas (1992) Distinguished Service Award, American Association of Tissue Banks (1994) Senior Arkansans Hall of Fame (1995) Silver Beaver Award, Boy Scouts of American (1998) Distinguished Alumni Award, University of Iowa (2006)
In December, 2020, Sinclair's group published that three Yamanaka transcription factors, Oct4, Sox2, and Klf4, when delivered together in a virus, could safely reverse the age of human and mouse cells, and restore the vision of old mice and mice with glaucoma. In 2023, with Bruce Ksander's lab at Mass Eye and Ear, they presented a poster at the annual ARVO conference accompanied by a company press release claiming that vision could be restored in non-human primates. In January 2023, Sinclair's lab published research in Cell purporting to support his Information Theory of Aging, the idea that mammalian aging is due to the loss of epigenetic information, and that Yamanaka factors could exert a degree of artificial control over senescence and rejuvenation in mice. The paper received a formal reply pointing out that the treatment used in the paper is known to produce p53-dependent cell death in a 30-day period in which the mice were not observed. Sinclair's claims of reverse aging have received criticism from other scientists.
transcript of unknown function (TUF) Any RNA transcript whose function is unclear. Such transcripts may include functional non-coding RNAs which have not yet been studied in detail as well as spurious transcripts without any definite function. The DNA sequences from which TUFs are transcribed are generally located in intergenic or intronic regions of the genome. See also junk RNA.
Zverev started his 2022 season by representing Germany at the ATP Cup. Germany was in Group C alongside Great Britain, the US, and Canada. Against Great Britain, he beat Cameron Norrie. Great Britain ended up winning the tie over Germany 2–1. Against the US, he defeated Taylor Fritz. Germany won the tie 2–1 over the USA. Against Canada, he lost to Félix Auger-Aliassime in three sets. Canada won the tie over Germany 2–1. Germany not only failed to qualify for the semi-finals, but they also ended third in Group C. Seeded third at the Australian Open, he reached the fourth round where he was defeated by 14th seed, Denis Shapovalov, in straight sets. After the Australian Open, Zverev played at the Open Sud de France. As the top seed, he made it to the final where he lost to sixth seed Alexander Bublik. Seeded second at the Mexican Open, Zverev played in what was the record latest match ever played, defeating Jenson Brooksby at 4:55 A.M. He was then defaulted from the tournament ahead of his following match against compatriot, Peter Gojowczyk, for violently and repeatedly hitting the umpire's chair with his racket after his loss in doubles. Representing Germany in the Davis Cup tie against Brazil, he won both of his matches by beating Thiago Seyboth Wild and Thiago Monteiro. Germany ended up winning the tie over Brazil 3–1 to qualify for the Davis Cup Finals. Seeded third at the Indian Wells Masters, he was stunned in his second-round match by Tommy Paul.
Sources: en.wikipedia.org
== Biochemistry == In prokaryotes and eukaryotes, GGT consists of two polypeptide chains, a heavy and a light subunit, processed from a single chain precursor by an autocatalytic cleavage. The active site of GGT is known to be located in the light subunit. Co-translational N-glycosylation serves a significant role in the proper autocatalytic cleavage and proper folding of GGT. Single site mutations at asparagine residues were shown to result in a functionally active yet slightly less thermally stable version of the enzyme in vitro, while knockout of all asparagine residues resulted in an accumulation of the uncleaved, propeptide form of the enzyme.
== External links == "Cyanogen Bromide MSDS Number: C6600". J. T. Baker. 1996-08-12. Teeri, A. E. (1948). "Thiamine and the Cyanogen Bromide Reaction". Journal of Biological Chemistry. 173 (2): 503–505. doi:10.1016/S0021-9258(18)57422-6. PMID 18910706.
While slavery had technically been banned by colonial France in French West Africa (including Mauritania) already in 1905, this had been a purely nominal ban. The 1981 ban on slavery was not enforced in practice, as legal mechanisms to prosecute those who used slaves were not implemented until 2007.
1995 membership 1,789. Grants scholarships and donations to St. Tikhon's Seminary and Monastery, St. Vladimir's Orthodox Theological Seminary; and the Monastery of the Transfiguration, Orthodox Press Fund, Alaskan Fund and the UPMC Children's Hospital of Pittsburgh.
Medication Medical approaches include enhancement of residual enzyme activity (in cases where the enzyme is made but is not functioning properly), inhibition of other enzymes in the biochemical pathway to prevent buildup of a toxic compound, or diversion of a toxic compound to another form that can be excreted. Examples include the use of high doses of pyridoxine (vitamin B6) in some patients with homocystinuria to boost the activity of the residual cystathione synthase enzyme, administration of biotin to restore activity of several enzymes affected by deficiency of biotinidase, treatment with NTBC in Tyrosinemia to inhibit the production of succinylacetone which causes liver toxicity, and the use of sodium benzoate to decrease ammonia build-up in urea cycle disorders.
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.
Dry powder is usually held frozen, shielded from light, and kept away from moisture. Desiccant packaging limits hydrolysis during storage. Solutions are typically aliquoted and frozen once, because repeated thawing shortens useful life.