PT 141 (Bremelanotide) When its Monday and you need a little boost., PT 141 to the rescue. This tan & tingle peptide helps stimulate the receptors (MC3 R and MC4 R) in the hypothalamus, a brain region involved in Not the same from a safety standpoint. Unless youre trying to get tanned (please dont use a tanning bed), PT141 is always going to be the answer. In the 1990s, researchers at the University of Arizona were testing Melanotan II as a tanning agent. During clinical trials, they noticed something unexpected: the compound was causing spontaneous erections in male PT 141 Peptides Melanotan 2 Melanotan II