Thioperamide is a potent HRH<sub>4</sub> antagonist and selective HRH<sub>3</sub> antagonist capable of crossing the bloodâÂÂbrain barrier. It was used by Jean-Charles Schwartz in his early experiments regarding the H<sub>3</sub> receptor. Thioperamide was found to be an antagonist of histamine autoreceptors, which negatively regulate the release of histamine. The drug enhances the activity of histaminergic neurons by blocking autoreceptors, leading to greater release of histamine.
Its action on H<sub>3</sub> receptors is thought to promote wakefulness and improve memory consolidation.