Melanotan II is a synthetic analogue of the melanocortin peptide hormone alpha-melanocyte stimulating hormone (α-MSH) that occurs naturally. In usage, Melanotan II has been revealed to have aphrodisiac and melanogenesis (tanning) effects that have been subjected to clinical trials and preliminary studies. The compound is a cyclic lactam analogue of α-MSH that has an amino sequence named MTII (Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-NH2). Notably, no government drug regulatory agency across the world had approved for the use of any compound incorporating the Melanotan II peptide by 2010
Malanotan II is used for tanning of the skin and producing of erections in men with erectile dysfunction when administered as a shot under the skin. Malanotan II is safe when used under strict medical supervision for treating erectile dysfunction. However, it may cause stomach cramps, tiredness, nausea, spontaneous erections of the penis, and darkened skin.
Melanotan II has been a new treatment for rosacea discussed in the various rosacea support groups on the internet.
Melanotan I and Melanotan II are both analogs of the peptide hormone alpha-melanocyte stimulating hormone (a-MSH) that tend to induce skin tanning. Melanotan II has the additional effect of increasing libido.
Melanotan II is an α-MSH analog which underwent clinical trials for the treatment of erectile dysfunction. Preliminary double-blind, placebo-controlled studies demonstrated the efficacy of melanotan in inducing penile erection in men with erectile dysfunction, although in a very restricted population.Unfortunately, there are no experimental data on the mode of action of melanotan II, as melanotan II is the first α-MSH agonist inducing penile erection when injected peripherally.
Illustration of the proerectile effect of melanotan II (MT-II) in humans. Placebo (A) or MT-II (B, 25 ug/kg and C, 133 ug/kg) was injected subcutaneously in patients and RigiScan recording was performed from 6 h. Apparent erections developed in 8 of 10 men treated with MT-II. (Reproduced with permission from Wessells H et al. Effect of an alphamelanocyte stimulating hormone analog on penile erection and sexual desire in men with organic erectile dysfunction. Urology 2000; 56:641–646.)
Melanotan II was first developed at the University of Arizona. Various studies conducted at the institution confirmed that the best defence against skin cancer was melanin activated in the skin, a tan. The researchers assumed that an effective procedure to reduce the rates of skin cancer in individuals would be by inducing the body’s natural pigmentary system to produce a tan that would be protective before exposure to UV. Melanogenesis is a process by which the skin’s pigment cells (melanocytes) produce the hormone α-MSH naturally causes the skin's pigment (melanin).
After numerous clinical trials by administration of the endogenous hormone to the body, the scientists found that though it appeared to work, α-MSH had a very short half-life in the body to be practical as a therapeutic drug. Therefore, they opted to look for a more stable and potent alternative that would be more practical. Subsequently, after numerous trials, they developed Melanotan I and after that Melanotan II.
Melanotan II is widely sold online and in beauty salons as well as gyms as melanotan in their marketing. These products purport to contain the same chemical composition as afamelanotide. These products have been declared illegal and do not have the same chemical components as Melanotan II. As such, countries issues warnings against their use.