I took 20mg Vyvanse at 1pm yesterday and at 7pm, my heart beats normal (Slower). I'm very sensitive to stimulants now. The same thing happened today because it's 7pm and my heart rate is 90bpm (Instead of 100-110bpm). The Vyvanse kicks in in about 40 minutes.

Is it because of the peak? Something like that?

Would Dexedrine 5mg 2-3x a day be a better option until I build tolerance to the side effects and increase a small bit to get the benefit of the therapeutic effects?

I don't think I'll take the Vyvanse tomorrow and see what happens.. To see how tired and unfocused I am..

Any insight into this please reply..