MD breaking down Melanotan II Part 2 of my peptide series. The research, the risks, the reality. Long term safety data? Nonexistent. Melanotan peptide might seem like the cool thing to doit makes you look tan., But these unregulated injections come with real risks., They can cause unpredictable skin changes, including darkening of Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn There has been a worrying increase in the number of young people using sunbeds. Some people are also using nasal sprays and injections with melanotan II in to boost their tan. This isn't