I looked it up in my old PCOS book by Thatcher (as I haven't taken any medication for it) and he is pro-birth control pills to balance your hormones and stop the thinning hair. The book also suggests Rogaine.
I was curious about taking silica-- http://www.livestrong.com/article/33...thinning-hair/
Silica is a trace mineral, and while your body needs only a small amount, that amount is essential for your health, including that of your skin and scalp, says Vital Health Zone. This mineral helps to strengthen your blood vessels and improve circulation, which can stimulate the blood flow to your scalp and encourage growth. It also is a necessary component of your skin’s connective tissues and helps to strengthen your bones, nails and hair.