Just as there are several different forms of HRT, there are also several ways the medication can be administered. The main difference is in the bleeding pattern that results. The three main HRT regimens are described below

Continuous Therapy

Continuous estrogen therapy with added progestogen medication has now become the most common way to take HRT. You can take a daily tablet of estrogen or wear a skin patch twice a week. Progestogen is taken in pill form. Over 90 percent of women will have a monthly period on this regimen if the uterus is intact. Note your bleeding pattern, which should occur after you stop taking progestogen. If bleeding begins before you stop taking progestogen, the dose of progestogen may be too low for you; work with your doctor to adjust it.

Cyclical Therapy

Estrogen and progestogen taken cyclically is a less common method of taking HRT. Estrogen is taken from the first to the 21st day of the cycle, and progestogen for the last 12 or 13 days of the cycle. Both medications are stopped on the 21st day and a withdrawal period will occur between the 22nd and 28th days - the patch or pill-free days. Over 90 percent of women who have not had a hysterectomy will experience a withdrawal menstrual period in the interval between ending one treatment and beginning the next. However, bleeding usually lessens over time and may disappear altogether.

A recently introduced method of cyclical therapy is to take progestogen once every three months. You go two months without a period, then bleed in the third month, so that you have four periods a year.