Tenocyclidine (TCP) was discovered by a team at Parke-Davis in the late 1950s. It is a dissociative anesthetic drug with psychostimulant and hallucinogenic effects. It is similar in effects to phencyclidine (PCP) but is considerably more potent.
Due to its similarity in effects to PCP, TCP was placed into the Schedule I list of illegal drugs in the 1970s, although it was only briefly used in the 1970s and 1980s and is now little known. It has been identified in combinations with Nicotine in illegal substances sold as PCP in the US in 2022.