Low dose hormone replacement therapy: clinical efficacy

The frequency of hormone replacement therapy (HRT) users has increased during the last 2 decades. A majority of women taking HRT prefer to use formulations that will not induce bleeding disturbances. Accordingly many women prefer continuous combined HRT to obtain amenorrhoea. Previously comparatively high doses of estrogens and progestogens were prescribed to women in the climacteric period. Low doses of estrogens such as estradiol 1 mg and conjugated equine estrogens 0.3 mg orally per day or transdermally applied estradiol 25 mug per 24 hours have been shown to be effective for the treatment of vasomotor symptoms and for prevention of bone loss. With low dose HRT in a continuous combined regimen amenorrhoea will be obtained in a majority of women after a few months of treatment. Low doses of progestogen especially if given on a continuous basis have been shown to protect the endometrium from hyperplasia. Favourable effects in lipid- and lipoprotein patterns have been reported. In addition, fewer side effects such as mastalgia have been found during treatment with low dose regimen compared to high doses. For women requesting HRT it might be a rational alternative to begin with low dose formulations since these doses are sufficient for the majority of women.