Rio de Janeiro, Brazil — Topical progesterone creams have been touted as a "natural" alternative to hormone replacement therapy and have been widely advertised in women's magazines and over the internet as an alternative option for postmenopausal women. Among the many claims made for these products is that they can prevent the bone loss that occurs after the menopause, and some even claim that they can increase bone mineral density (BMD).
But they don't, Dr Gill Pearson (Southampton General Hospital, UK) told the recent World Congress on Osteoporosis. She reported a double-blind placebo-controlled study in which postmenopausal women using a topical progesterone cream (containing 40-80 mg progesterone) twice-daily over 2 years actually showed a fall in BMD levels [ 1 ].
"Despite strong marketing claims to the contrary, doctors should advise women not to use these progesterone creams as protection against osteoporosis," says Pearson.
The trial that Pearson reported enrolled 45 postmenopausal women aged 49-70 years and measured BMD at the lumbar spine at baseline and at 6, 12, and 24 months. In addition, the researchers carried out blood, saliva, and urine assays in order check that progesterone was being absorbed through the skin, and they measured biochemical markers to assess bone turnover (the urine NTX/creatinine ratio).
For the first year, one group used a topical progesterone cream (1.5% USP) containing 40 mg progesterone twice daily, while the other group used placebo. Both groups showed a decrease in mean lumbar spine BMD at 12 months, and there was no significant difference between the two.
Mean lumbar spine BMD at 12 months
During the second year, the trial became an open-label study. The first group doubled the dose and applied 80 mg progesterone twice daily, whereas the placebo group started using the cream, at 40 mg progesterone twice daily, and also took a vitamin and mineral supplement. Both groups again showed a decrease in BMD at 24 months.
At the same time, a parallel group of 15 postmenopausal women used transdermal continuous combined HRT (containing estradiol 50 Â¿g and norethisterone 170 Â¿g/day) throughout the study. This group of women showed an increase in BMD at 12 months of about 5.5% (95% CI 2.10-8.97) and a further increase at 24 months. In addition, this group showed a 35% decrease in bone turnover by the end of year 2, whereas the other two groups showed no significant change from baseline values over the course of the study.
Even though the progesterone cream was well absorbed, it did not prevent bone loss or increase bone mass in postmenopausal women, Pearson and colleagues concluded. She suggested that perhaps a different dose or formulation or delivery system would be effective, noting that animal studies have shown that progesterone stimulates bone formation.\
Pearson GC, McCullough WL, Taylor PA et al. Topical natural progesterone cream effect on postmenopausal bone loss: a two-year double-blind, randomized, placebo-controlled trial. From IOF World Congress on Osteoporosis Osteoporosis International 2004; 15(suppl 1):abstract OC
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Cite this: Zosia Chustecka. Topical progesterone creams ineffective against bone loss - Medscape - May 27, 2004.