Prempro/Premphase (generic: conjugated estrogens/medroxyprogesterone) are prescription medications used to treat moderate to severe hot flashes and vaginal dryness, burning, and irritation after menopause. Prempro and Premphase are also used to reduce the risk of getting osteoporosis. These medicines both contain estrogen and progesterone hormones, which are necessary for many processes in the body and ovulation and menstruation.

Prempro and Premphase come in tablet form to be taken once daily, with or without food. Both Prempro and Premphase contain the same hormones, but the dosage is different for each medication. Prempro contains a lower amount of hormones in each tablet and is taken every day throughout the year. Premphase contains a higher amount of both hormones and an alternating schedule of 14 days of taking just estrogen is followed by 14 days of taking both estrogen and progesterone.

Commons side effects of Prempro/Premphase include headache, breast pain, and irregular vaginal bleeding.