Hi, I am on my third week of 30mg each morning, 7-8am is when I take it, never after 8am. I was diagnosed at 23 but didn't start until 26.
Sides during first week or so: increase in blood pressure, slightly higher heart rate, decreased appetite, teeth grinding, could feel a "crash" in late afternoon, some difficulty sleeping ~1030pm
After the second week: unsure about blood pressure, body has adjusted some and I believe it to be more normal now. Heart rate still increases slightly, appetite still suppressed throughout the day (I eat a banana early and try and get ~20g protein by noon), not getting those "Crashes" that i had first week (or if anything, not so bad), I can sleep now and I am aware of the teeth grind thing but that has definately decreased.
Overall I think body adjusted to this well, may consider 40mg instead of 30mg. Don't think i'll go over 40mg personally. The focus benefit throughout the day really helps me with my productivity
Oh I should note I kept drinking coffee during all of this. When I first started (with those sides) I went from 4 to 2 cups a day. Now I'm back at around 3ish cups a day.
Vyvanse is a legally controlled substance in the US, so there is plenty of information publicly available on the subject. The most common side effects off the top of my head are reduced appetite, increased blood pressure, and sleep problems.
I've been taking Vivance for years. FWIW, I had some of those side effects when I first started taking it and they have subsided for me. I still feel like I benefit from the medication and haven't ever felt like 'abusing' it.