This article was written by a lady struggling with infertility, so her perspective is a little different than what we are aiming for here, but the article is very interesting.
She says that herbs with phytoprogestins like damiana and red clover, actually block progesterone in the body.
This would be bad for us PMS girls who are already low on progesterone. She also seems to make a correlation between low progesterone and infertility (also mentioned on Dr. John Lee's site). So...if she is correct, and damiana and red clover block progesterone, then they would not be good to take, unless one had excess progesterone, something I have not heard of. Also, I wonder if those herbs would counteract the effects of pro-progesterone herbs, like vitex.
I am actually taking damiana, not for NBE specifically, but for low libido, and it has worked wonders for that. So I am not going to quit taking it. But I wonder if it is another mechanism that makes it work for libido, besides the progesterone/estrogen balance. Because I know that I am low-progesterone (since I have had severe PMS and lots of improvement from vitex), so I doubt that lowering my progesterone could be helping me, unless the damiana is helping me in some completely different way.
I was thinking of taking red clover in my new program that I'll be starting soon, but now I think I may just stick to fenugreek and saw palmetto (in addition to the other herbs I already take, like vitex and damiana).