Progesterone Alone May Help Hot Flashes
Estrogen Alternative Needs More Study, Experts Say
'Natural' Progesterone for Hot Flashes
The results are ''moderately impressive," says Carolyn Alexander, MD, a reproductive endocrinologist and infertility specialist at Cedars-Sinai Medical Center and assistant professor of obstetrics and gynecology at the University of California Los Angeles David Geffen School of Medicine, who reviewed the study results for WebMD.
''Using Prometrium alone may be considered an interesting new use of the medication," she tells WebMD.
Though it has been approved by the FDA since 1998, the new study is believed to be the first to look at micronized progesterone alone for hot flash and night sweat relief, Prior says.
Alexander cautions that more study is needed. What is yet to be proven, she says, is whether the regimen will be safe long-term for bone health. She says researchers also need to show no increased risk for cancers.
Addressing Bone, Cancer Concerns
Prior agrees more study is needed but suspects the micronized progesterone will not adversely affect bone health, pointing to previous research suggesting that estrogen and progesterone when given together improve bone health more than estrogen alone.
The micronized progesterone alone regimen may actually decrease cancer risk, she says, although that's not proven. She points to research showing that estrogen is involved in cell growth (including cancer cells) and progesterone is involved in cell maturation and differentiation. "That would be expected to decrease cancer risk," she says.
On the Prometrium web site, the manufacturer, Abbott, cautions women taking the hormone for the indicated uses to have a yearly exam by their health care provider ''due to increased risk of breast cancer while using this medication."
The study was funded by donations to the Centre for Menstrual Cycle and Ovulation Research at the university; Schering Canada and Besins Healthcare provided the progesterone and placebo.
This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.