Menopause messes with pH, too: When women stop producing estrogen, many experience vaginal dryness and thinning, which ends up killing off lactobacilli so pH starts to rise. In fact, postmenopausal women often have a pH in the range of 5 to 6, which is slightly higher than ideal, says Dr. JoAnn V. Pinkerton, executive director of the North American Menopause Society and a professor of obstetrics and gynecology at the UVA Health Center.