Vaginal estrogen is prescribed for the genital and urinary symptoms of menopause. It appears to be safe overall, according to a new analysis of data from the Women’s Health Initiative Observational Study, published in the journal Menopause.
The study found that, over an average of seven years, the risk of stroke, heart disease, invasive breast cancer, colorectal cancer, endometrial cancer, deep vein thrombosis, pulmonary embolism, and premature death was not higher among users of vaginal estrogen than among nonusers. This was true of women who had a hysterectomy as well as those who retained their uterus. The researchers controlled for age, past hormone use, history of cancer, smoking, alcohol intake, and other factors.
Some 20 to 45 percent of menopausal women experience genital symptoms including vaginal dryness, burning, and pain during sex, due to thinning of the vaginal walls, as well as urinary symptoms such as frequent or painful urination and recurrent urinary tract infections. Low-dose vaginal estrogen—in creams, tablets, or an estradiol ring—can be prescribed as an effective alternative to systemic (oral or transdermal) hormone therapy, though it doesn’t treat hot flashes.
Keep in mind that this was an observational study, and its results need to be confirmed by long-term clinical trials, which have yet to be done on vaginal estrogen.
Still, “our findings help to fill important knowledge gaps” regarding the safety of vaginal estrogen, the researchers wrote. The FDA requires vaginal estrogen formulations to carry the same boxed warning label as systemic hormone therapy, based only on data extrapolated from clinical trials on the latter and despite the fact that systemic use involves significantly higher hormone doses. The FDA is currently considering modifying the warning on vaginal estrogen to better reflect the safety evidence.
Lending more support for the use of vaginal estrogen is the North American Menopause Society (NAMS). According to its 2017 position statement, “low-dose vaginal estrogen preparations are effective and generally safe” for treating the genito-urinary symptoms of menopause, “with minimal systemic absorption, and [are] preferred over systemic therapies.” Still, NAMS advises that women with breast cancer consult an oncologist before using it because of “the risk of small increases in circulating estrogens.”
Also see Is Hormone Therapy Okay, Again?