Progesterone was originally considered an optional part of hormonal therapy. Now there is beginning to be growing evidence that progesterone has benefits beyond this. It increases the protection against osteoporosis and fractures. That is about 100 milligrams of micronized progesterone versus the typical 200 mg. This level protected the uterus but did not interfere with estrogen's blood fat lowering properties the way the higher dose did.
Herbs have much anecdotal support from many women.
They have not been formally studied to any great degree. In combination with life-style changes that most herbalists follow, there is good relief. If you are, what is your opinion of their natural progesterone and their estrogen. I am not familiar with Women's International. I can say that there are a number of natural women's pharmacies, some sincere, some out to make a fast buck.