Btw, I've come to realize that PM has similar side effects like birth control does, e.g. lengthening or eliminating cycles. I would say they (women) only need 500mg during the first half.........isn't that what the manufactures suggest anyway.

In large part this effect is caused from the HPA axis (hypothalamus pituitary axis). One risk factor we "all " might miss is the fact of permanently damaging the thyroid, I haven't seen evidence yet, however the possiblty does exist (imo).