PT141 and MT2 are peptides mostly used by bodybuilders and partygoers. They where tested for PT141 in a phase3  clinical trial, to be used as a tanning agent and to increase the libido. They didn't make into the "real world" and no pharmaceutical company can ask huge prices to sell it to the general public (like they did/do with Viagra). But it is used in the underground scene and underneath this article we will inform you about "real life' usage.

Horn of rhinoceros. Penis of tiger. Root of sea holly. Husk of the emerald-green blister beetle known as the Spanish fly. So colorful and exotic is the list of substances that have been claimed to heighten sexual appetite that it’s hard not to feel a twinge of disappointment on first beholding the latest entry—a small white plastic nasal inhaler containing an odorless, colorless synthetic chemical called PT-141. Plain as it is, however, there is one thing that distinguishes PT-141 from the 4,000 years’ worth of recorded medicinal aphrodisiacs that precede it: It actually works.