Tenocyclidine

Tenocyclidine (TCP, thienyl cyclohexylpiperidine) is a dissociative anesthetic drug with stimulant and hallucinogenic effects. It is similar in effects to phencyclidine but is considerably more potent. TCP has slightly different binding properties to PCP, with more affinity for NMDA receptors but less affinity for sigma receptors. Because of its high affinity for the PCP binding site on the NMDA receptor, the 3H radiolabelled form of TCP is widely used in research into NMDA receptors.

TCP acts primarily as an NMDA Receptor Antagonist which blocks the activity of the NMDA Receptor, however its increased stimulant effects compared to PCP suggests it also has relatively greater activity as a dopamine reuptake inhibitor. 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 abused in the 1970s and 1980s and is now little known.