Health expert says Melanotan II darkens skin moles and can make melanoma hard to detect Herald Sun Melanotan: Get a Real Tan with a Peptide Revitalyze MD That quick tan injection is NOT worth the risk., Melanotan peptide injections stimulate pigment cells, and its use has been linked to rapid changes in moles, including the potentially fatal skin Melanotan II synthetic tanning drug molecule. 3D rendering. Not approved as drug. Atoms are represented as spheres with conventional color coding: h Stock Photo Alamy