Estrogen replacement regimen

An improved pharmaceutical preparation comprising a plurality of doses arranged in alternating standard dose estrogen phases and ultra-low dose estrogen phases, each phase consisting of from about 1 to about 4 consecutive daily unit doses or an equivalent thereof, wherein the daily unit doses of the standard dose estrogen phases contain an amount of from about 0.5 mg to about 1.0 mg of estradiol, and the daily unit doses of the ultra-low dose of estrogen phases contain an amount selected from-about 0.005 mg to about 0.01 mg of estradiol, for administration to a female in need of estrogen replacement therapy.