Phencyclidine (PCP) Profile Phencyclidine (PCP) is a synthetic dissociative drug originally developed as a general anesthetic. The effects of dissociative drugs like PCP include feelings of detatchment from the environment and self.In its pure form, PCP is a white crystalline powder that dissolves easily in water or alcohol. As a liquid, it is clear, yellow, or tan and often is sold in vanilla extract bottles.he effects of dissociative drugs like PCP include feelings of detatchment from the environment and self. In its pure form, PCP is a white crystalline powder that dissolves easily in water or alcohol. As a liquid, it is clear, yellow, or tan and often is sold in vanilla extract bottles.