Progesterone capsules can be taken if you have progesterone deficiency during pregnancy preparation. If the progesterone level is normal, you do not need to take progesterone capsules. Progesterone capsules are progesterone drugs that can be used to supplement progesterone deficiency in the body. When progesterone levels are normal, taking progesterone capsules may instead cause abnormal menstruation, which may affect normal pregnancy preparation. If the progesterone level is insufficient, it may cause follicular dysplasia and abnormal ovulation, resulting in abnormal menstruation and infertility. It is also likely to cause miscarriage or embryonic dysplasia after pregnancy, and progesterone capsules need to be taken under medical supervision. Progesterone capsules may cause side effects such as vaginal bleeding and alteration of menstrual cycle, and should be taken under medical supervision.