Hi,
What is the difference between the two in the effectivity of it. I know one is extended release, but what that would do? Does it help.
Thanks.

XR is basically two doses. The first is released immediately, just as you'd get from "regular" Adderall. The other is released 4-5 hours later, as if you took another dose of "regular". The capsules are half immediate, half delayed. So 40 mg of Adderall XR is like taking 20 mg of instant release, then 4-5 hours later taking another 20 mg.