I take it orally and vaginally (in two different types of vaginal supplements).
It's definitely different for everyone. The vaginal supplements are generally stronger, and they get the progesterone right where it needs to be, but not everyone needs it.
My thoughts would be, if you have lining concerns, spotting, or are taking oral progesterone and still have low levels, you may want to discuss switching to vaginal (or adding a vaginal) with your doctor.
No worries.
The concerns there is really progestins. Prometrium NOT a synthetic progestin. It is a bioidentical hormone.