A practical reference on alpha-MSH analog: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-08-05. Anything still debated is marked as such rather than presented as settled.
Research interest has centred on photoprotection and pigmentation, with a smaller body of work on appetite and sexual function. Published human data remain limited to small, frequently uncontrolled studies, and the compound has never received marketing approval from a national medicines regulator. Most laboratory work treats it as a pharmacological tool for probing melanocortin signalling in cell culture or animal models. Whether pigmentation changes observed in people translate into measurable protection against ultraviolet-induced DNA damage remains an open question.
Melanotan-2 is a synthetic cyclic heptapeptide designed as an analogue of alpha-melanocyte-stimulating hormone, the naturally occurring peptide involved in pigmentation signalling. Its sequence is conventionally written as Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2, with a lactam bridge joining the aspartate side chain to the lysine side chain. The empirical formula is C50H69N15O9 and the monoisotopic mass lies near 1023.5 daltons. N-terminal acetylation and the D-configured phenylalanine both increase resistance to enzymatic breakdown compared with the parent hormone.
Early published reports described melanotan-2 as a tanning agent without sun protection, which means darkening is not the same as protection against ultraviolet radiation. Later studies explored the peptide in erectile dysfunction, hemorrhagic shock, and some skin conditions. No regulator in the United States or Europe has approved it for clinical use. Many products labelled melanotan-2 are sold without approval and their identity and purity are unverified. Its long-term safety in humans remains an open question.
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.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | Melanotan II; MT-II; N-acetyl-norleucyl-cyclo[Asp-His-D-Phe-Arg-Trp-Lys] amide | Naming follows peptide convention; the numeral distinguishes it from melanotan-1 |
| Molecular formula | C50H69N15O9 | Includes the lactam bridge; no counter-ion assumed |
| Monoisotopic mass | 1023.53 Da | Free base; salts and counter-ions shift the observed value |
| Appearance | White to off-white lyophilised powder | Batch-to-batch colour variation is not itself proof of impurity |
| Typical analytical method | RP-HPLC purity determination with ESI-MS identity confirmation | Retention time alone does not establish sequence identity |
Receptor studies place melanotan-2 among non-selective melanocortin agonists, binding MC1R, MC3R, MC4R and MC5R rather than a single subtype. Activation of MC1R on cutaneous melanocytes raises tyrosinase activity and shifts pigment synthesis toward eumelanin, which is darker and more photostable than pheomelanin. Central receptors, particularly MC4R, are associated with appetite suppression and with reported effects on sexual function. Because subtype selectivity is low, the same molecule engages pigment, metabolic and vascular pathways at once, and this breadth is a common explanation offered for the range of adverse events described in user reports.
No regulatory authority has approved melanotan-2 for human use, and several countries classify it as a prescription-only or controlled substance, which restricts lawful supply. Material sold online is generally labelled as a research chemical and is not required to meet pharmaceutical standards of identity or purity. Published human data consist mainly of small uncontrolled studies, case reports and adverse-event notifications, so the evidence base is descriptive rather than confirmatory. Whether repeated melanocyte stimulation alters long-term naevus behaviour remains an open question that no completed trial has resolved.
Melanotan-2 is a synthetic cyclic heptapeptide designed as a structural analogue of alpha-melanocyte-stimulating hormone, the endogenous tridecapeptide that regulates pigment production. Two modifications distinguish it from the natural hormone: norleucine replaces methionine at the N-terminus, which limits oxidation, and a D-phenylalanine substitution raises receptor affinity. The ring is closed through an aspartate-lysine lactam bridge, giving the molecule a constrained conformation. The free base has a molecular mass near 1024 daltons, and commercial material is usually supplied as an acetate salt. It appears in the literature as a research peptide rather than an approved therapeutic agent.
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.
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.
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.
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.
=== Chemical-pharmaceutical industry and laboratories === Acetonitrile is used as a solvent, particularly in the pharmaceutical industry. According to a market analysis, approximately 180,000 tons of acetonitrile were produced worldwide in 2022, of which around 70% was consumed by the pharmaceutical sector. It is also one of the most important solvents for analyses performed by high-performance liquid chromatography. The thermal decomposition of azobisisobutyronitrile (AIBN) and related compounds (e.g., azobis(cyclohexanecarbonitrile)) generates relatively stable radicals; accordingly, these compounds are used as radical initiators in radical reactions, particularly polymerizations. The quinone DDQ, which contains two nitrile groups, is a widely used oxidizing agent, including in pharmaceutical synthesis. Nitrile groups can be incorporated into biomolecules as probes for infrared spectroscopic investigations. Some nitriles serve as starting materials for the synthesis of pharmaceuticals. Ketoprofen is an anti-inflammatory agent approved in some EU countries; propionitrile is used in its industrial synthesis.
=== Solvation effects === Solvation significantly affects the basicity of amines. N−H groups strongly interact with water, especially in ammonium ions. Consequently, the basicity of ammonia is enhanced by 1011 by solvation. The intrinsic basicity of amines, i.e. the situation where solvation is unimportant, has been evaluated in the gas phase. In the gas phase, amines exhibit the basicities predicted from the electron-releasing effects of the organic substituents. Thus tertiary amines are more basic than secondary amines, which are more basic than primary amines, and finally ammonia is least basic. The order of pKb values (basicities in water) does not follow this order. Similarly, aniline is more basic than ammonia in the gas phase, but ten thousand times less so in aqueous solution. In aprotic polar solvents such as DMSO, DMF, and acetonitrile the energy of solvation is not as high as in protic polar solvents like water and methanol. For this reason, the basicity of amines in these aprotic solvents is almost solely governed by the electronic effects.
Membrane osmometry is a method that relates the osmotic pressure of a solution to its number-average molar mass, but is less effective in species that can permeate the membrane. Additionally, the absolute molar mass can be determined using sedimentation equilibrium experiments or using independently determined sedimentation and diffusion coefficients. Other methods replace SEC with different separation techniques such as asymmetric flow field flow fractionation (AF4) or involve different detection systems such as matrix assisted laser desorption/ionization-time of flight-mass spectrometry (MALDI-TOF-MS).
The detailed study of reproductive structures in plants led to the discovery of the alternation of generations, found in all plants and most algae, by the German botanist Wilhelm Hofmeister. This discovery is one of the most important made in all of plant morphology, since it provides a common basis for understanding the life cycle of all plants.
Itopride increases acetylcholine concentrations by inhibiting dopamine D2 receptors and acetylcholinesterase. Higher acetylcholine increases GI peristalsis, increases the lower esophageal sphincter pressure, stimulates gastric motility, accelerates gastric emptying, and improves gastro-duodenal coordination. Itopride given as a single dose study found that it also raises levels of motilin, somatostatin and lowers levels of cholecystokinin, as well as adrenocorticotropic hormone. These effects may also contribute to itopride's pharmacology.
Sources: en.wikipedia.org
== Ecology == The moringa tree is not affected by any serious diseases in its native or introduced ranges. In India, several insect pests are seen, including various caterpillars such as the bark-eating caterpillar, the hairy caterpillar, or the green leaf caterpillar. Budworms from the Noctuidae are known to cause serious defoliation. Damaging agents can also be aphids, stem borers, and fruit flies. In some regions, termites can also cause minor damage. If termites are numerous in soils, insect-management costs are not bearable. The moringa tree is a host to Leveillula taurica, a powdery mildew, which causes damage in papaya crops in south India. Furthermore, the caterpillars of the snout moth Noorda blitealis feed primarily on the leaves and can cause complete leaf loss.
=== Guns === Kennedy had an "A" rating in 2016 and "A+" rating in 2022 from the NRA Political Victory Fund (NRA), which endorsed him during both elections. Kennedy opposed a rule from the Bureau of Alcohol, Tobacco, and Firearms that effectively reclassified guns equipped with pistol stabilizing braces as short-barreled rifles, which would require gun owners to register the weapons with the federal government. He argued the rule harmed gun owners with disabilities who needed the braces to use handguns. He tried to pass a joint resolution of disapproval under the Congressional Review Act to block the rule, but the resolution failed by a vote of 50–49. Kennedy supports gun ownership for self-defense and often says, "I believe love is the answer. I do. But I also own a handgun, just in case." Kennedy supports protecting due process rights for veterans who seek assistance from Veterans Affairs. He introduced a bill to prevent the VA from reporting veterans to the FBI's National Instant Criminal Background Check System without due process if they seek financial support.
== Disorders of thyroid gland (240–246) == 240 Simple and unspecified goiter 240.9 Goiter, unspec. 241 Nontoxic nodular goiter 241.0 Thyroid nodule 241.9 Goiter, unspec. nontoxic nodular 242 Thyrotoxicosis with or without goiter 242.0 Goiter toxic, diffuse 242.9 Hyperthyroidism, NOS 243 Congenital hypothyroidism 244 Acquired hypothyroidism 244.0 Hypothyroidism, post-surgical 244.1 Hypothyroidism, post-ablative 244.9 Hypothyroidism, unspec. 245 Thyroiditis 245.0 Thyroiditis, acute 245.1 Thyroiditis, subacute 245.2 Thyroiditis, chronic, Hashimoto's 246 Other disorders of thyroid 246.2 Thyroid cyst
Portal venous systems A portal venous system is a series of veins or venules that directly connect two capillary beds. The two systems in verebrates are the hepatic portal system, and the hypophyseal portal system.
Sources: en.wikipedia.org
25 February The North Vietnamese Foreign Ministry on Radio Hanoi stated that the "South Vietnamese people" could attack U.S. forces "at any place on Vietnamese territory" and denied that there was any agreement not to conduct such attacks in return for the bombing halt.
=== Endoplasmic reticulum === The discovery of an animal cell AMPylase, followed by the discovery of its ER localisation and that BiP is a prominent substrate for its activity were important breakthroughs. BiP (also known as Grp78) had long been known to undergo an inactivating post-translational modification, but its nature remained elusive. Widely assumed to be ADP-ribosylation, it turns out to be FICD-mediated AMPylation, as inactivating the FICD gene in cells abolished all measurable post-translational modification of BiP. BiP is an ER-localised protein chaperone whose activity is tightly regulated at the transcriptional level via a gene-expression program known as the Unfolded Protein Response (UPR). The UPR is a homeostatic process that couples the transcription rate of BiP (and many other proteins) to the burden of unfolded proteins in the ER (so-called ER stress) to help maintain ER proteostasis. AMPylation adds another rapid post-translational layer of control of BiP's activity, as modification of Thr518 of BiP's substrate-binding domain with an AMP locks the chaperone into an inactive conformation. This modification is selectively deployed as ER stress wanes, to inactivate surplus BiP. However, as ER stress rises again, the same enzyme, FICD, catalyses the opposite reaction, BiP de-AMPylation. An understanding of the structural basis of BiP AMPylation and de-AMPylation is gradually emerging, as are clues to the allostery that might regulate the switch in FICD's activity but important details of this process as it occurs in cells remain to be discovered.
4-HO-DPT acts as a high-efficacy partial agonist to full agonist of the serotonin 5-HT2A, 5-HT2B, and 5-HT2C receptors. It has more than two orders of magnitude greater potency as an agonist of the serotonin 5-HT2A and 5-HT2B receptors than as an agonist of the serotonin 5-HT2C receptor. Hence, it shows considerable selectivity for the serotonin 5-HT2A receptor over the serotonin 5-HT2C receptor. Compared to psilocin (4-HO-DMT), 4-HO-DPT has about the same potency and efficacy as a serotonin 5-HT2A receptor agonist, has about the same potency but is much more efficacious as a serotonin 5-HT2B receptor agonist (EmaxTooltip maximal efficacy = 39% vs. 94%, respectively), and has about the same efficacy but approximately 10-fold lower potency as a serotonin 5-HT2C receptor agonist. 4-HO-DPT produces the head-twitch response, a behavioral proxy of psychedelic effects, in rodents. Its potency for inducing the head-twitch response in mice is about 4- or 5-fold lower than that of psilocin.
== Membership of professional bodies == Member of the Governing Council of the Pharmacists Council of Nigeria, Nnamdi Azikiwe University Member of the Nanomedicine Society of Nigeria Member of the Global Young Academy Member of the American Society for Cell biology Member of many other professional bodies including, Institute of Public Analysts of Nigeria; West African Society for Pharmacology, Nigeria; Society for Medicinal Plant Research, Germany; Pan African Medical Mycology Society, South Africa; International Society for Anti-infective Pharmacology; Materials Society of Nigeria; and, Nigerian Society of Forensic Scientists (Pioneer member of Board of Directors)
In May 2021, Freddy's hired Chris Dull as CEO to take over the top post from co-founder Randy Simon. In August 2022, Freddy's hired Brian Wise as COO to take over the operations post from co-founder Scott Redler. In November 2022, the company signed a master franchise and development agreement that will allow the brand to expand into Canada by 2025, opening restaurants in nine provinces. In August 2025, Rhône Group agreed to acquire Freddy's from Thompson Street Capital Partners, who acquired the brand in 2021, for an enterprise value of around $700 million. The acquisition was finalized in September 2025.
Sources: en.wikipedia.org
It is a synthetic cyclic heptapeptide analogue of alpha-melanocyte-stimulating hormone, containing seven amino acids with a lactam ring and a D-configured phenylalanine residue. It is supplied as a lyophilised powder for laboratory research.
The natural hormone is a linear tridecapeptide that is rapidly degraded in circulation. Melanotan-2 is shortened, cyclised, N-terminally acetylated, and carries a D-amino acid substitution, all of which slow enzymatic breakdown.
No national medicines regulator has approved melanotan-2 for therapeutic or cosmetic use. In several jurisdictions it is treated as an unapproved prescription medicine, and its legal classification differs from country to country.
No. It is a laboratory-made peptide, while the natural hormone is alpha-melanocyte-stimulating hormone, a longer peptide produced by the pituitary gland and by skin cells. Melanotan-2 mimics only a short active region of that hormone and contains non-natural residues such as D-phenylalanine.