Imagine just wanting to be jacked and tan and you end up like this? Melanotan II is a peptide that increases the melanin in your skin and can give men a boner that Australia's Therapeutic Goods Administration is urging consumers to not use tanning products containing a synthetic peptide called 'Melanotan'. The drug can cause serious side affects, such a kidney failure, chest pains, acne, Can You Overdose on Melatonin? Viral 'Barbie drug' for tanning can cause brain swelling and even cancer, experts warn