Vaginal forms of HRT are called “local” therapy. Pills and skin patches are considered “systemic” therapy, because the medication delivered affect the entire body. Doctors generally prescribe vaginal applications of HRT to specifically treat symptoms such as vaginal dryness. For treatment of hot flashes, systemic therapy is recommended.
There are various dosing regimens for combination hormone therapy, although there is no consensus as to which is best. When estrogen and a progestogen are prescribed together, dosing schedules include:
- Cyclic hormone therapy is often recommended when a woman is starting menopause. With this therapy, estrogen is taken in pill or patch form for 25 days, with progestin added somewhere between days 10 - 14. The estrogen and progestin are used together for the remainder of the 25 days. Then, no hormones are taken for 3 - 5 days. There may be monthly bleeding with cyclic therapy.
- Continuous, combined therapy involves taking estrogen and progestin together every day. Irregular bleeding may occur when starting or switching to this therapy. Most women stop bleeding within 1 year.
"Biodentical" Hormones. Bioidentical” hormone replacement therapy is promoted as a supposedly more natural and safer alternative to commercial prescription hormones. Bioidentical hormones are typically compounded in a pharmacy. Some compounding pharmacies claim that they can customize these formulations based on saliva tests that show a woman’s individual hormone levels.
The FDA, and many professional medical associations, warn patients that “bioidentical” is a marketing term that has no scientific validity. Formulations sold in these pharmacies have not undergone FDA regulatory scrutiny. Some of these compounds contain estriol, a weak form of estrogen, which has not been approved by the FDA for use in any drug. In addition, saliva tests do not give accurate or realistic results, as a woman’s hormone levels fluctuate throughout the day.
FDA-approved hormones available by prescription come from different synthetic and natural sources, including plant-based. (For example, Prometrium is a progesterone derived from yam plants.)
Benefits of HRT
Periomenopausal and Menopausal Symptoms. HRT is mainly recommended for relieving menopausal symptoms, including hot flashes, night sweats, vaginal dryness and accompanying pain during sexual intercourse, and sleep problems. Evidence is mixed as to whether HRT helps improve mood; the progestogens in EPT may worsen mood in some women. HRT does not prevent certain other problems associated with menopausal changes, such as thinning hair or weight gain.
Osteoporosis. Estrogen increases and helps maintain bone density. HRT may be useful for some women at high risk for osteoporosis, but for most women the risks do not outweigh the benefits. Other drugs, such as bisphosphonates, should be considered first-line treatment for osteoporosis. [For more information, see In-Depth Report #18: Osteoporosis.]
Adverse Effects of HRT
Review Date: 07/26/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.