In this chapter, we present ethnographies from the Philippines, Indonesia, Ethiopia, and France that together show how young people use chemicals to shape their bodies, enhance their sexual pleasure, and foster their sexual hygiene. Through these intimate stories, we show how young people use chemicals to try out different sexual identities, connect with partners, enhance sexual experiences, and prevent unwanted pregnancies, as well as enhance their sexual performance. In this way, chemicals are used both as a way to relate to others and also to explore themselves. In Chemical Sexualities, we show how young people use chemicals to address their sexual needs and explore their sexual desires in four distinct ways: to shape their bodies, to enhance sexual performance, for sexual hygiene and STI prevention, and to abort unwanted pregnancies. Each of these “do-it-yourself” chemical sexualities involves various practices, which we compare and contrast across field sites to gain a better understanding of what is at stake in young people’s sexual lives.