Hello, Thanks for writing to us. Irregular period is quite common with PCOS. Cycloreg (Norethisterone) is NOT much effective in this case. I suggest you to take combined oral contraceptive pills like Diane-35 etc, which is the mainstay of treatment. It is taken for continuous 21 days on scheduled time with 7 days gap to get period. Metformin can be added. In addition, you have to follow some basic guideline: a) Low carbohydrate diet (avoid fatty or sugary beverage) with more green vegetables. Drink more water or take fruit juice. b) Regular moderate physical exercise by means of running/ jogging/ treadmill/ walking to reduce or control body weight. c) Avoid mental stress or depression by regular yoga or meditation for 15 to 30 min. Take adequate bed rest or sound sleep. Hope, above information is helpful to you. Good luck.