Estrogen Only Therapy (ET) refers to the administration of estrogen without the addition of progesterone or other hormones. This therapy is primarily used to manage symptoms associated with menopause, such as hot flashes, vaginal dryness, and osteoporosis. ET is often recommended for women who have undergone a hysterectomy, as they do not require progesterone to counteract the effects of estrogen on the endometrial lining.