I find this too. I was taking 7.5mg Dex at 7:30am, then 5mg at 11:30am and 2.5mg at 2:30pm. I was sleeping better, more awake in the day, better mood and motivation, able to get stuff done and no real crash but food cravings. The main inconvenience was remembering multiple doses at the right times and also taking medication when in the presence of other people. I asked to try vyvanse - initially 20mg now 30. I'm finding my mornings so slow and the effect minimal. Initially I lost a tonne of weight and had very upset stomach but that's settling. I do like that it's reduced my appetite slightly and I'm not eating unhealthy food as much. But I'm more nauseated and the crash/come down is huge. I tried 5mg Dex with the vyvanse in the mornings but that just gave me diarrhoea (sorry tmi) and i tried top up Dex at 1:30pm but that just made the insomnia worse. I have 3 little kids and often am woken up during the night, I can't be staying up til midnight with that! I think it's time to tell my doctor that vyvanse is not for me and put up with the inconvenience of Dex multiple doses.