A prolactin modulator is a drug which modulates the secretion of the pituitary hormone prolactin from the anterior pituitary gland. Prolactin inhibitors suppress and prolactin releasers induce the secretion of prolactin, respectively. D2 receptor agonists that are described as prolactin inhibitors include the approved medications bromocriptine, cabergoline, lisuride, metergoline, quinagolide, and terguride and the never-marketed agent lergotrile. Other dopamine agonists and dopaminergic agents, for instance levodopa (L-DOPA), can also inhibit prolactin secretion.