m a 22 year old male and am currently taking 50
mg vyvanse daily. Just got it upped from 40
mg. You asked about taked it as need, and I'll tell you what my doctor told me.
He actually recommended that I take it only as need because your tolerance doesn't build up as fast when you do this, therefore, making vyvanse more effective in the long run. And about how you're crashing really hard and feeling queezy. I believe that is normal, however you might be on too high of a dose.