"I first started taking this when I was 18. After taking it for over a year and still not having my periods regulated I decided to get off of it. I got on it again a year and a half ago (I&#039;m 21 now) and I&#039;m still not pleased with it. If I forget to take a pill one day I&#039;ll spot for up to a week. My periods are really light every 3 months, but they can last up to 2 weeks. I&#039;ve gained 10 lbs while being on it. I&#039;m just finishing up my last pack and am getting back on Yaz."