A frozen embryo cycle normally takes three weeks. It can be done in a natural cycle or in a cycle with medication, in what we call a substitute cycle. In the natural cycle we take advantage of the way the ovaries work to have a follicle that will be selected and at the same time will produce estradiol to make the endometrium thicker. As I mention it may take around three weeks depending on how long the cycle of the patient is. However, we are talking about a substitute cycle with estradiol intake. It also may take around 3 weeks softly speaking in that cycle we need to use estradiol to make the endometrium thicker and after having that endometrium in the best conditions possible we will up progesterone. The progesterone will also be added in the natural cycle to increase the implantation rate.
