Hi, I take 70 mg Vyvanse per day for my ADD. My wife and I are trying to get pregnant. I ve read that because it is an amphetamine, it will decrease my fertility. How long would I have to go off of it for my fertility to go back up? I m 220 lbs, 34 years old, non-smoker, and rarely drink. I m worried that it could take weeks to get out of my system. That would not be good for my career as I d be napping several times a day and I d probably put on 10 lbs.