When a woman takes Toremifene, it may cause a missed period or irregular vaginal bleeding. Toremifene refers to Toremifene Citrate, which is a more commonly used anti-estrogen drug that is used clinically to treat metastatic breast cancer in postmenopausal women who are estrogen receptor positive. When premenopausal women take this medication, the body is left in a hypoestrogenic state due to the fact that toremifene suppresses the production of estrogen from the ovaries, and this may lead to scanty periods or amenorrhea. However, irregular vaginal bleeding may sometimes occur. Patients may experience hot flashes, excessive sweating, fatigue, dizziness, rash, and itching while taking Toremifene. Osteoporosis may also occur if this medication is taken for a long time.