Earlier quoted context omitted.
To be clear, 120mg is what he takes first thing in the morning. He takes more throughout the day. I’d guess he takes 500+ in a day.
That is impossible. There is no one someone's heart would be able to take that. I take 60 mg daily of Vyvanse and I'm pretty wired all day. I can't even fathom the effects of that on a human body. Is he like 300 lbs?
You're right that 500mg is far into overdose territory for novice users. But, he probably has been using for a long time and has a very high tolerance.