you should take anywhere from 20mg to 120mg (i think) a day for 15-20 weeks. Blood tests should be done everymonth. I was on it twice and planning on going back on it after my cycle if i break out bad, 1 week in and seeing acne on my face already....GRRR Its all good though, just be careful shits horrible for ya. Very bad sideeffects in some, its been known to cause severe depression, almost close to suicidal (as is in my case, and in a friend of mine) but ones you're off of it you feel great, look great and i believe it was DAMN WELL worth. But my acne was very severe and after i barely washed my face anymore and had perfect skin. Good Luck.