its for women who have low progesterone problems. Unless you have indications of it, you wont even be tested for this (indications include previous miscarriages and possible fertility problems, thus having medical help to conceive)
Most women have no problems at all with progesterone... and many who do its only indicative of an already failed pregnancy rather than one where she just has low progesterone.
I tested at the lower end (I have history of miscarriage) and am not on suppositories (or pills, or cream) because everything else is healthy but they are keeping an eye on my progesterone levels to see if they drop further, possibly meriting the use of suppositories.
