Melanotan II is a synthetic version of α- melanocyte stimulating hormone that was created, synthesized and developed at The University of Arizona and the Arizona Cancer Center. Melanotan II is a shortened, circular version of melanotan-1. Both Melanotan-1 and Melanotan II develop dermal pigmentation without sun exposure but because Melanotan II had libido enhancement and spontaneous erections as side effects, it is now being developed as a sexual and erectile dysfunction drug.
Melanotan (MT) and Melanotan II (MT-II) are both analogs of the alpha-melanocyte stimulating hormone (α-MSH) which is produced within the pituitary gland. Along with other melanocortins, they are responsible for various internal human functions including skin and hair pigmentation, appetite, libido and physical sexual arousal. Whilst these effects have been observed in both sexes, it is worth noting that increases in libido and sexual function are exclusive to MT-II.
Both Melanotan and Melanotan II have been shown in the clinical setting to increase pigmentation without exposure to UV, a feature that is also confirmed anecdotally by users that report tanning in areas of the body that would seldom see the light of day! However, the process of tanning is greatly expedited by UV exposure. It is worth noting that tanning effects may not be uniform throughout the skin. This is in part due to the half life and distribution of the drug itself, but primarily in response to the concentration of melanocytes within certain areas of the skin. Most will notice the greatest tanning effect on the face, arms, abdominal region. Interestingly, the genitals have one of the highest concentrations of melanocytes enabling these particular areas to respond very well to the peptide in conjunction with UV exposure.