Effective endometrial protection was proven in the PEPI* Trial, an NIH-sponsored, independent, 3-year, multicenter, randomized, double-blind, placebo-controlled study of healthy postmenopausal women with an intact uterus (N=596) aged 45 to 64 years.[1]

Protect the endometrium from hyperplastic changes associated with estrogen-only therapy[1]

Estrogen combined with cyclic micronized progesterone:

• Resulted in no statistical difference in the occurrence of abnormal endometrial biopsy compared to placebo (P=0.16).[1]
  

Normal endometrial biopsy results over 36 months[1]


*Postmenopausal Estrogen/Progestin Interventions Trial.
†Statistically significant at P<0.001 vs estrogen alone.
‡P=0.16 vs placebo.

Active regimens contained conjugated equine estrogens (CEE) (0.625 mg/day) alone or in combination with continuous medroxyprogesterone acetate (MPA)
(2.5 mg/day), cyclic MPA (10 mg/day for 12 days/cycle), or cyclic PROMETRIUM® (200 mg/day for 12 days/cycle).

The most common adverse events reported in postmenopausal women receiving PROMETRIUM® 200 mg were: breast tenderness, dizziness, abdominal bloating, vaginal discharge, chest pain, and diarrhea.[2]

Next: Proven effective treatment for secondary amenorrhea

References:
1. The Writing Group for the PEPI Trial. Effects of hormone replacement therapy on endometrial histology in postmenopausal women: the Postmenopausal Estrogen/Progestin Interventions (PEPI) Trial. JAMA. 1996;275:370-375. 2. PROMETRIUM® [package insert]. Marietta, Ga: Solvay Pharmaceuticals, Inc.; 2004.