Estrogen Only (ERT)

Therapies containing just estrogen are commonly referred to as estrogen replacement therapy, or ERT. Because of the increased risk of endometrial cancer (lining of the uterus), long-term ERT is usually only offered to women who have had uterus removal through a hysterectomy.

ERT can be administered in a variety of ways. Systemic ERT delivers estrogen so that it circulates throughout the body, whereas local ERT delivers estrogen to a particular area of the body, such as the vagina to treat vaginal dryness or vaginal atrophy.

Systemic ERT can be delivered as oral medicines, skin patches, gels, injections, implanted pellets, and sprays. These medicines may help to reduce hot flashes and vaginal dryness and may reduce your risk of osteoporosis.

Local ERT can be delivered directly into the vagina by a pill, cream, or ring. Because only a small amount of estrogen circulates in the body with local ERT, these products typically only help with local symptoms, such as vaginal dryness. They are usually not helpful in controlling other symptoms of menopause, such as hot flashes, or in preventing osteoporosis.

Estrogen Plus Progesterone (HRT)

Hormone replacement therapy (HRT) is treatment that combines ERT (estrogen only) with a form of the hormone progesterone. This may consist of natural progesterone or a synthetic progesterone, called progestin. Both forms are also called progestogens.

There are several HRT schedules and methods of delivery available, including:

• Cyclic HRT —This treatment provides estrogen for 25 days each month, adding progesterone on the last 10-14 days out of 25, followed by 3-6 days of no therapy. This way, both hormones are "cycled." Cyclic HRT may cause uterine bleeding (a menstrual period) when the progesterone cycle ends. Hot flashes are also more likely to return on the days when no hormones are taken.
• Continuous-Cyclic HRT —This treatment provides estrogen every day, with progesterone added 10–14 days of each month. Like cyclic HRT, the main side effect is uterine bleeding (in the form of a period).
• Continuous-Combined HRT —This treatment provides both estrogen and progesterone every day. The daily dose of progesterone is much lower than the daily dose in cyclic therapy, which may result in a lower total dose over the course of the month. Breakthrough uterine bleeding occurs in some women on this schedule, but usually stops within the first year of therapy.
• Intermittent-Combined HRT —This treatment provides estrogen every day, with progesterone added intermittently in "on-off" cycles. The cumulative monthly dose of progestogen is about half of that of a continuous-combined pattern. .