These months comprise part of perimenopause , the three to five years before the last period, when hormonal levels may fluctuate. Progesterone and Combined Hormone Replacement Therapy. Of concern, however, are two studies published in 2000 that suggest that the addition of a progestin to estrogen in hormone therapy may actually increase the risk for breast cancer beyond that of estrogen alone. Progestins may sometimes be prescribed alone for hot flashes and other acute menopausal symptoms. Natural progesterone does not have as many side effects as synthetic progestins do, but it can cause drowsiness and dizziness.
Compliance appears to be excellent.
No hormones are taken for the next five or six days. Since the body's premenopausal hormone balance is being mimicked, mild vaginal bleeding will usually occur at the end of the cycle. Such bleeding does not indicate any significant health problem, nor does it indicate a return of fertility, but some women find it unpleasant. This simultaneous approach, however, may not be as heart protective and some studies indicate that it may still carry a small risk for uterine cancer. Timing of Hormone Replacement Therapy For women who do choose hormone replacement therapy, the next question is when to start it.