Prempro side effects can occur during treatment or shortly after treatment stops and include breast tenderness and enlargement, weight gain and irregular periods, loss of appetite or stomach nausea, muscle pain, and water retention, according to WebMD. These symptoms should disappear once the medication is out of the patient's system; however, patients who take Prempro carry a greater risk for developing heart disease, stroke, breast cancer, and blood clots for the rest of their life, according to Mayo Clinic.
Prempo is used in hormone therapy and is a "combination estrogen-progestin pill," notes MayoClinic. Doctors are now recommending that hormone therapy not be used in most postmenopausal women for disease prevention because the risks, in most cases, outweigh the benefits. Prempro, along with other hormone therapies, was previously used to help prevent memory loss and heart disease in postmenopausal women. Hormone therapy is still used in some cases at lower doses to treat hot flashes, night sweats, difficulty sleeping, and dryness or itching in the vagina, according to MayoClinic.
The Kronos Early Estrogen Prevention Study, also known as KEEPS, has shown that young postmenopausal women may be able to take hormone therapy without as many risks as older postmenopausal women. Patients who use hormone therapy have different risk levels as well depending on whether or not their uterus has been removed, whether or not estrogen is given separately or in combination with progestin, the age of the patient, and the condition of the patient's heart, according to MayoClinic.