Melanotan 2（MT-2）は、ヒトアルファメラノサイト刺激ホルモン（α-MSH）の合成バージョンです。もともとは1980年代にアリゾナ大学で開発されましたが、α-MSHがげっ歯類の性的覚醒と皮膚の暗化を引き起こしたことがわかった後です。もともと太陽のない日焼けオプションとして設計されたMT-2は、最終的に次のような幅広い効果があることがわかりました。

• 性的興奮の増加、
• 日焼けまたは皮膚色素沈着を促進する、
• 強迫行動を減らす、
• 中毒を制御し、
• 飢えと戦う、
• グルカゴン生産の削減、および
• 自閉症の逆の特徴。

ペプチド配列：nle-asp（1）-his-d-phe-arg-trp-lys（1）
分子式：C50H69N15O9
分子量：1024.198 g/mol
Pubchem cid： 92432
CAS番号：121062-08-6

ソース：パブ

メラノタン2およびメラノコルチンシグナル伝達

メラノタン2は、メラノコルチン受容体と結合することによりその効果を生み出します。 5つの既知のメラノコルチン受容体があり、それぞれ異なる機能を備えています。 MT-2は、主にMC-4RおよびMC-1Rに結合することが知られていますが、MC-3Rに弱く結合します。

• MC-1R：メラニン細胞に見られる、MC-1Rの刺激は皮膚と髪の暗くなることを引き起こします。
• MC-2R：副腎に見られるMC-2R結合は、コルチゾールなどの副腎ホルモンの分泌を促進します。
• MC-3R：MC-3Rは食欲制御とエネルギー規制に関与していますが、この受容体について他にほとんど知られていません。
• MC-4R：MC-4Rの刺激は、摂食と性的行動の変化を引き起こします。また、男性の勃起機能とエネルギー恒常性にも影響します。
• MC-5R：MC-5Rは、汗腺と膵島細胞で発現しています。

メラノタン2と自閉症

MT-2の最新の研究所見は、ペプチドが自閉症スペクトラム障害（ASD）の一般的に使用されるマウスモデルで特定の自閉症の特徴を逆転させることができることを示しています。この状態の治療法はありませんが、最近の検索では、オキシトシン療法がASDに関連する行動上の問題のいくつかを軽減するのに役立つ可能性があることが示されています。自閉症につながることが知られている母体免疫活性化のマウスモデルを使用して、研究者は、オキシトシン放出を刺激することが知られているMT2がASDに対抗するか、一般的なASD行動を減らすことができるかどうかを調査しました。彼らの研究により、MT-2の投与は、この特定のモデルの自閉症に関連するコミュニケーションの減少、社会的相互作用の障害、および反復行動を逆転させることが明らかになりました。実際、研究者は、MT-2投与が脳の特定の部分でオキシトシン受容体の発現を増加させ、それらの領域でのオキシトシンシグナル伝達とASD固有の行動との直接的な相関を示唆していることを発見しました。^[1].

Impact of MT-2 on sociability in rats with ASD (MIA) showing that MT-2 returns sociability ratings to near the baseline of control animals (C57).
Source: PubMed

These findings not only suggest potential avenues for developing a treatment for ASD, they have helped to define a specific brain pathway that may be integral to the development of ASD in the first place. These findings could help scientists develop a complete model of ASD and thus both treatments and preventative measures.

Melanotan 2 and Hunger

There is good evidence to suggest that MT-2 can reduce fat storage and hunger behavior in animal models. Researchers have found that the melanocortin-4 receptor (MC-4R) plays a role in food preferences and intake and that MT-2 is a potent agonist of MC-4R. Administration of MT-2 to mice causes significant reductions in how much food they consume, but also changes their preference for fatty foods. Mice given MT-2 ignore fatty foods, which they would otherwise prefer. Similarly, mice devoid of the MC-4R receptor consume fatty foods almost exclusively and are immune to the effects of MT-2^[2].

The effects of MT-2 are similar to those of the hormone leptin, sometimes called the satiety hormone because it reduces cravings and food intake. Leptin, however, has never been useful in the treatment of obesity, even in individuals who are leptin deficient. This is likely because there are two pathways for satiety, called leptin-dependent and leptin-independent pathways. Research suggests MT-2 is more effective in stimulating both pathways and thus may be a more effective exogenous treatment for reducing hunger^{[3], [4]}. This latter finding has been bolstered by the discovery that thyrotropin-releasing hormone (TRH) gene expression, which has long been known to play a role in the leptin-satiety pathway, is also affected by MC-4R stimulation^[5]. Both MT-2 and leptin are thought to cause an increase in TRH expression in the paraventricular nucleus of the hypothalamus, a region of the brain associated with satiety and food intake, but only MT-2 crosses into the central nervous system in concentrations high enough to have an effect on TRH expression.

Melanotan 2 and Diabetes

The pathogenesis of diabetes is defined by high blood sugar levels, hypersecretion of glucagon, and the production of ketone bodies^[6]. It has been known for some time that leptin counteracts these factors by increasing the uptake of glucose, suppressing glucagon production, and interfering with the pathway that leads to ketone body formation. These actions do not depend on insulin and thus leptin signaling is being actively investigated as an alternative means by which diabetes might be treated.

Research has revealed that leptin’s effects on blood sugar are regulated through melanocortin receptors and that MT-2 produces similar effects^[7]. This is significant because leptin has its primary effects in the brain but does not cross the blood-brain barrier as readily as MT-2. Thus, exogenously administered leptin does not reach the CNS in substantial quantities, a fact that reduces its effectiveness as a drug and hands an advantage to MT-2 even though the effects of the two peptides on melanocortin receptors are nearly identical.

Melanotan 2, Impulse Control and Alcohol Intake

In keeping with the idea that MT-2 may affect oxytocin signaling and thus behavior in ASD, research also reveals that the MC-4R receptor may play a role in impulse control. Past studies in rats have shown that administration of MT-2 reduces alcohol intake and increases water intake even in rats that prefer alcohol^[8]. More recently, research has revealed that melanotan-2 works synergistically (boosting efficacy more than seven-fold) with naltrexone to blunt binge-like ethanol intake in mice^[9].

Percent of baseline alcohol consumption in mice treated with naltrexone or naltrexone and MT-2.
Source: PubMed

These findings suggest that MT-2 might not only be an effective treatment in alcohol-related disorders, but that the peptide is tapping into a more fundamental process of craving and desire in the mammalian brain. This research may open up pathways to a deeper understanding not just of alcohol abuse and hunger, but the role of oxytocin in impulsive behavior. It may even help researchers identify craving pathways and advance our understanding of human motivation in aspects of life ranging from work to relationships.

Melanotan 2 and Erectile Dysfunction

Erectile dysfunction (ED) is often attributed to vascular issues and can be effectively treated in a majority of men via sildenafil (Viagra) and other drugs that improve blood flow by reducing vascular resistance. Not all ED is due to vascular issues, however, and so sildenafil and similar drugs are ineffective in a small percentage of men and in the vast majority of women who suffer from hypoactive sexual desire disorder. It has long been known that MT-2 is an effective treatment for ED, but research suggests that it may have more wide-ranging application than drugs like sildenafil due to its actions in the central nervous system. In a study of men who had failed treatment with Viagra, eighty percent responded to MT-2 treatment^[10]. MT-2 has been actively investigated in the past as a treatment for both male and female sexual desire disorders.

Melanotan 2 Impacts Wakefulness

We don’t understand a great deal about sleep and arousal, except that the regulation of consciousness is a complicated part of higher brain function. Research has revealed, however, that several different populations of neurons in the brain are critical to different aspects of arousal such as sleep onset, depth of consciousness, duration of sleep, and more. The paraventricular nucleus of the hypothalamus is one area of the brain that regulates arousal in response to stress, social interaction, feeding, and other cues.

Research using mice shows that stimulation with melanotan 2 increases arousal via interaction with neuronal fibers of the paraventricular nucleus. In fact, stimulation of this pathway can lead to immediate transition to wakefulness from both NREM and REM sleep[13]. Further research in this area may uncover how to improve sleep and enhance concentration via the melanocortin system, making peptides like melanotan 2 potential nootropics.

Melanotan 2 and Alzheimer’s Disease

Past research has shown that activation of pro-opiomelanocortin (POMC)-derived neuropeptide can rescue some of the synaptic dysfunction that is caused by the neurofibrillary (amyloid) tangles that arise in Alzheimer’s Disease. POMC-derived neuropeptide can be activated by melanocortin receptors, so mouse models were employed to investigate whether melanotan 2 could be useful in this setting. This research showed that melanotan 2 substantially reduces amyloid accumulation and prominently reduces the A1 subtype of reactive astrocytes. This latter fact is important because A1 astrocytes are thought to be a primary driver of neurotoxicity and neuron death in Alzheimer’s Disease[14]. These findings suggests that melanocortin activation may be a potential therapeutic target in Alzheimer’s Disease. This represents a novel pathway for investigating Alzheimer’s Disease treatment and may similarly provide a means of mitigating neurotoxicity in other degenerative brain diseases.

MT-2 Research

MT-2 is a heavily researched peptide, particularly regarding human behavior, sexual desire, and impulse control. The peptide, in various forms, has been investigated in clinical trials, though problems with routes of administration have forced scientists back to the drawing board. There is active and ongoing research into the benefits of this particular peptide.

MT-2 exhibits minimal to moderate side effects, low oral and excellent subcutaneous bioavailability in mice. Per kg dosage in mice does not scale to humans. MT-2 for sale at

The above literature was researched, edited and organized by Dr. Logan, M.D. Dr. Logan holds a doctorate degree from Case Western Reserve University School of Medicine and a B.S. in molecular biology.

Dr. Wessells is a UW professor, chair of the Department of Urology, and has served on several national and international professional and government committees, including the WHO International Consultations on Erectile and Sexual Dysfunction, an NIDDK working group on urological complications of diabetes, and a NIH symposium on diabetes. He is a surgeon, researcher and expert on urogenital trauma and erectile dysfunction. His clinical interests include reconstructive surgery of the genitourinary tract, acute injury management and complex surgery for male sexual dysfunction.  His research interests are in urogenital trauma epidemiology and management; the physiology and pathophysiology of erectile dysfunction; reconstructive surgery; crash injury mechanics; and urological complications of diabetes. A proerectile melanocortin agonist developed by Dr. Wessells and his collaborators at the University of Arizona is in clinical trials for the treatment of erectile dysfunction.

Dr. Wessells is being referenced as one of the leading scientists involved in the research and development of Melanotan 2. In no way is this doctor/scientist endorsing or advocating the purchase, sale, or use of this product for any reason. There is no affiliation or relationship, implied or otherwise, between

1. E. Minakova et al., “Melanotan-II reverses autistic features in a maternal immune activation mouse model of autism,” PLoS ONE, vol. 14, no. 1, Jan. 2019. [PubMed]
2. A. van der Klaauw et al., “Role of melanocortin signaling in the preference for dietary macronutrients in human beings,” Lancet Lond. Engl., vol. 385 Suppl 1, p. S12, Feb. 2015. [PubMed]
3. H. Shimizu, K. Inoue, and M. Mori, “The leptin-dependent and -independent melanocortin signaling system: regulation of feeding and energy expenditure,” J. Endocrinol., vol. 193, no. 1, pp. 1–9, Apr. 2007. [Research Gate]
4. C. Bjørbaek and A. N. Hollenberg, “Leptin and melanocortin signaling in the hypothalamus,” Vitam. Horm., vol. 65, pp. 281–311, 2002. [PubMed]
5. F. Guo, K. Bakal, Y. Minokoshi, and A. N. Hollenberg, “Leptin Signaling Targets the Thyrotropin-Releasing Hormone Gene Promoter in Vivo,” Endocrinology, vol. 145, no. 5, pp. 2221–2227, May 2004. [PubMed]
6. Y. H. Lee, M.-Y. Wang, X.-X. Yu, and R. H. Unger, “Glucagon is the key factor in the development of diabetes,” Diabetologia, vol. 59, no. 7, pp. 1372–1375, 2016. [PubMed]
7. C. Toda et al., “Distinct effects of leptin and a melanocortin receptor agonist injected into medial hypothalamic nuclei on glucose uptake in peripheral tissues,” Diabetes, vol. 58, no. 12, pp. 2757–2765, Dec. 2009. [PubMed]
8. D. A. York, S. Boghossian, and M. Park-York, “Melanocortin activity in the amygdala influences alcohol intake,” Pharmacol. Biochem. Behav., vol. 98, no. 1, pp. 112–119, Mar. 2011. [PubMed]
9. M. Navarro, F. Carvajal, J. M. Lerma-Cabrera, I. Cubero, M. J. Picker, and T. E. Thiele, “Evidence that Melanocortin Receptor Agonist Melanotan-II Synergistically Augments the Ability of Naltrexone to Blunt Binge-Like Ethanol Intake in Male C57BL/6J Mice,” Alcohol. Clin. Exp. Res., vol. 39, no. 8, pp. 1425–1433, Aug. 2015. [PubMed]
10. “Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study. – PubMed – NCBI.” [Online]. Available: https://www.ncbi.nlm.nih.gov/pubmed/9679884. [Accessed: 15-May-2019].
11.  WESSELLS, H. , HRUBY, V. J., HACKETT, J. , HAN, G. , BALSE‐SRINIVASAN, P. and VANDERAH, T. W. (2003), MT‐II Induces Penile Erection via Brain and Spinal Mechanisms. Annals of the New York Academy of Sciences, 994: 90-95. doi:10.1111/j.1749-6632.2003.tb03166.x
12.  Wessells, H. (1998). Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: Doubleblind placebo controlled crossover study. Nature.com. Available at: https://www.nature.com/articles/3900371.pdf
13.  M. T. Islam et al., “Vasopressin neurons in the paraventricular hypothalamus promote wakefulness via lateral hypothalamic orexin neurons,” Curr. Biol. CB, pp. S0960-9822(22)01121–6, Jul. 2022, doi: 10.1016/j.cub.2022.07.020. [PubMed]
14. J. K. Y. Lau et al., “Melanocortin receptor activation alleviates amyloid pathology and glial reactivity in an Alzheimer’s disease transgenic mouse model,” Sci. Rep., vol. 11, no. 1, p. 4359, Feb. 2021, doi: 10.1038/s41598-021-83932-4. [PubMed]

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The products offered on this website are furnished for in-vitro studies only. In-vitro studies (Latin: in glass) are performed outside of the body.  These products are not medicines or drugs and have not been approved by the FDA to prevent, treat or cure any medical condition, ailment or disease.  Bodily introduction of any kind into humans or animals is strictly forbidden by law.