[beverley.rose]

I'm afraid nobody ever measured that. My guess is: enough. Women who take 500 mg already see their acne clearing up. You have to add it up to what you get from other plants too, like even maize. The list starts bottom right on p. 27:
http://www.dweckdata.com/Published_papers/IJCD.pdf

You might like this http://www.puerariathai.com/pueraria-mirifica/clinical-information.htm

OTHER INGREDIENT CRITERIA & HUMIDITY
Analysis Result (s) Method
Miroestrol 76.00 ppm HPLC
Puerarin 40.00 ppm HPLC
Daidzin 0.56 mg/100gm. HPLC
Daidzein Less Than 10% HPLC
Genistin Less Than 10% HPLC

Beverley