To determine effectiveness of transdermal progesterone cream for controlling vasomotor symptoms and preventing postmenopausal bone loss.
We randomly assigned 102 healthy women within 5 years of menopause to transdermal progesterone cream or placebo. Study subjects and investigators were masked until data analysis was completed. An initial evaluation included complete history, physical examination, bone mineral density determination, and serum studies (TSH, FSH, lipid profile, and chemistry profile). Subjects were instructed to apply a quarter teaspoon of cream (containing 20 mg progesterone or placebo) to the skin daily. Each woman received daily multivitamins and 1200 mg of calcium and were seen every 4 months for review of symptoms. Bone scans and serum chemistries were repeated after 1 year.
Thirty of the 43 (69%) in the treatment group and 26 of the 47 (55%) in the placebo group complained initially of vasomotor symptoms. Improvement or resolution of vasomotor symptoms, as determined by review of weekly symptom diaries, was noted in 25 of 30 (83%) treatment subjects and five of 26 (19%) placebo subjects (P < .001). However, the number of women who showed gain in bone mineral density exceeding 1.2% did not differ (α = 05, power of 80%).
Although we found no protective effect on bone density after 1 year, we did see a significant improvement in vasomotor symptoms in the treated group.