Ospemifene (commercial name Osphena produced by Shionogi) is anoral medication indicated for the treatment of dyspareunia – pain during sexual intercourse – encountered by some women, more often in those who are post-menopausal. Ospemifene is a selective estrogen receptor modulator (SERM) that selectively binds to estrogen receptors and either stimulates or blocks estrogen's activity in different tissue types. It has an agonistic effect on the endometrium. It’s building vaginal wall thickness which in turn reduces the pain associated with dyspareunia. Dyspareunia is most commonly caused by "vulval and vaginal atrophy”.