Vasopressin is a anti-diuretic hormone produced by the pituitary gland. It has a reputation as a memory enhancer with claims being that it is responsible for imprinting new information into the brain's memory centers. It is thought to also play a role in memory retrieval.

Vasopressin potentiates neurotransmitter activity in the CNS by strong inhibition of neuronal serotonin and norepinephrine reuptake and weak inhivition of dopamine reuptake.