Preciado shows the ways in which the synthesis of hormones since the 1950s has fundamentally changed how gender and sexual identity are formulated, and how the pharmaceutical and pornography industries are in the business of creating desire. This riveting continuation of Michel Foucault's The History of Sexuality also includes Preciado's diaristic account of his own use of testosterone every day for one year, and its mesmerizing impact on his body as well as his imagination.