Might be worth a shot if you can lay your hands on them? I got some on Amazon (uncoated tablets rather than capsules, so need to take them quick!), £11 for 200 one a day.
Don't know what your circumstances are hormone wise but because I have PCOS and oestrogen dominance, the herbalist i was going to told me not to take soy at all (in fact she made me cut it out of my diet all together) as it counteracts the agnus castus, even if you take them a different points in your cycle xx