This is the way birth control pills work.
Every week has a different ratio of estrogen and progestin- to mimic the natural cycle .
The same can be true for the estrogen though this is rarely done today. This is when the estrogen and progesterone is taken every day. Products like Prempro are an example of this type of delivery system. HRT patches also deliver on a continuous basis. In Stephanie Bender's best seller, The Power of Perimenopasue, she covers all aspects of perimenopause and menopause.