Maybe a silly question, but here goes: Why do we need to use injectable or vaginal progesterone in the 2WW? Why can’t one use oral progesterone? (I assume it must be absorbed from gastrointestinal tract as progesterone is in birth control pills.)
This is due to the “1st pass” phenomenon. Oral absorption is not nearly sufficient enough to obtain and maintain adequate levels in the uterus.
- Answers kindly provided by Dr. Stephan Volschenk -
Tags: progesterone