Hormone Replacement Therapy

Low estrogen levels are associated with vaginal irritation, dry vaginal tissues, pain with intercourse, urinary frequency, and leakage of urine. A lack of estrogen can cause a change in the chemistry of the vagina, which can predispose you to a vaginal or urinary tract infection.

All estrogen is not created equal. Oral estrogen affects the body much differently than vaginal estrogen. Oral estrogen such as birth control pills and hormone replacement therapy (HRT) are metabolized by the liver. This causes an increase of sex hormone binding globulin (SHBG), a protein that binds to testosterone. When this occurs, testosterone levels decline. In some women (usually those taking low dose birth control pills), the effects can potentially lead to dry vaginal tissues, low sexual desire, and painful intercourse. Despite these possible side effects, birth control pills may be necessary to treat other medical conditions such as endometriosis or painful periods. In postmenopausal women, oral estrogen for hormone replacement therapy may be necessary in treating a woman with symptoms such as hot flashes.

Vaginal estrogen therapy does not lower systemic testosterone levels like oral estrogen does. Vaginal estrogen can be helpful in treating vaginal dryness and discomfort that can occur with breastfeeding, perimenopause or postmenopause, and in women with vulvar dermatologic conditions such as lichen sclerosus, and vulvodynia (vestibulodynia).

Facts About Estrogen

1. Oral/transdermal estrogen replacement therapy can be helpful in treating hot flashes, sleep disturbances, night sweats, irritability, and depression during menopause.

2. Oral/transdermal estrogen replacement (also known as unopposed estrogen) causes the lining of the uterus (endometrial lining) to become thick and this can lead to endometrial cancer. Therefore, it is important to take progesterone replacement as directed to prevent abnormal thickening of the uterus (endometrial hyperplasia).

3. It appears that concerns about HRT causing breast cancer have been overstated. The associated risk of breast cancer risk has not been consistent across studies. The Women’s Health Initiative (2003) found that oral estrogen alone actually reduced the risk of invasive breast cancer. The risk for breast cancer was not increased in women who used HRT for 5 years or less. There were 8 breast cancers per 10,000 women per year in the WHI participants who took conjugated estrogen 0.625 mg/medroxyprogesterone 2.5 mg. In addition, an analysis estimated that the number of excess breast cancer cases among women who started HRT at age 50 and used it for 5, 10, or 15 years was 2, 6, and 12 cases, respectively, per 1000 women.

4. Women with a family history of breast cancer often consider themselves to be at an increased risk for breast cancer if they use HRT. According to the Iowa Women’s Health Study, using HRT with a family history of breast cancer did not increase the patient’s risk for breast cancer; the risk did not significantly differ when compared to patients who did not use HRT.

Frequently Asked Questions

Question: I do not have a uterus and I was prescribed progesterone. Should I be concerned?

Answer: Yes because progesterone offers no health benefits to women without a uterus and may actually increase your risk for breast cancer.  In the WHI study, women who took Prempro (conjugated estrogen and medroxyprogesterone) had an increased breast cancer risk. Interestingly, women who took Premarin (congugated estrogen) actually had a decreased risk for breast cancer.

Question: What is progestogen?

Answer: Progestogen is a generic term for progesterone or progestin replacement therapy.

  • Prometrium is a progesterone that is considered a bioidential hormone because it is derived from plants. Prometrium has a similar chemical structure as the progesterone produced by your ovaries.
  • Provera and medroxyprogesterone are examples of a progestin. Progestins are considered synthetic types of hormone replacement.