Prempro & Premphase (conjugated estrogens/medroxyprogesterone acetate tablets)

The following drug information is obtained from various newswires, published medical journal articles, and medical conference presentations.


Approval Status:

Approved November 1995

Specific Treatments:

postmenopausal hormone replacement, postmenopausal osteoporosis

General Information

Prempro/Premphase is an estrogen plus progestin hormone replacement therapy.

Prempro/Premphase is specifically indicated for:

  • the treatment of moderate to severe vasomotor symptoms due to menopause
  • the treatment of moderate to severe vulvar and vaginal atrophy due to menopause 
  • the prevention of postmenopausal osteoporosis 

The recommended dose is as follows:

Prempro: one tablet containing conjugated estrogens (CE) plus medroxyprogesterone acetate (MPA) taken orally once daily. Premphase: one maroon tablet containing 0.625 mg CE taken orally on days 1 through 14, and one light-blue tablet containing 0.625 mg CE plus 5.0 mg MPA taken orally on days 15 through 28.

Clinical Results

Most studies have not shown a higher risk of breast cancer in women who have used estrogens. Some studies have reported that breast cancer developed more often in women who used estrogens for long periods of time or who used high doses for shorter time periods. The effects of added progestins on the risk of breast cancer are unknown. Some studies have reported a moderately increased risk in those taking combination estrogen/progestin therapy, even higher than the possible risk of taking estrogens alone. Other studies have not shown this relationship. The addition of progestin may have unfavorable effects on blood sugars and fats, which might make a diabetic condition worse.

Side Effects

The most commonly reported side effects in the clinical study were breast tenderness, headache, and abdominal pain. Rarely, however, were these serious enough to cause women to stop therapy.

Additional Information

Previously, physicians have prescribed estrogen and progestin for nonhysterectomized women needing hormone replacement therapy (HRT) in a variety of different regimens. Until now, a woman taking estrogen and progestin at different times throughout the month had to keep track of where she was in her cycle and whether she needed to take one tablet (estrogen alone), or two tablets (estrogen and progestin) on any given day. As a result, many women found their HRT regimens difficult to follow.

Some women should not take HRT. A woman should make sure her doctor or health care provider is aware of her personal or family health history before taking HRT. This history should include instances of breast cancer, breast lumps, abnormal vaginal bleeding, abnormal blood clotting, severe headache, dizziness, and liver disease. Women who are pregnant should not take HRT. Estrogens have been reported to increase the risk of cancer of the uterus in postmenopausal women.