I'm going to ask my doctor to switch me from XR to IR and I'm wanting to kind of explore what might be a proper dosage for me. I don't need adderall all the time. What I'm going to ask my doctor is for 20mg IR and do as follow if I can split it 10mg for class and 20mg for when I need to study. I don't need XR as that last all day and I have night classes so by time I take it in the morning, it's starting to wear off by time class starts.

I have the generic 20mg of IR. You can split it 4 ways on the pill, for easy controlled dosage. However, I'm not sure if taking half of the 20mg will result in 10mg for ~5 hours, or 10mg for half the time (2.5 hours). =X

i have the barr ones an yes you can split em

I have the generic 20mg of IR. You can split it 4 ways on the pill, for easy controlled dosage. However, I'm not sure if taking half of the 20mg will result in 10mg for ~5 hours, or 10mg for half the time (2.5 hours). =X

Amphetamine absorption & clearance is pretty linear, so taking half a dose of IR results in half the concentration for the same amount of time. The plot of the drug concentration in your body looks the same, it's just divided by two.

Because of the way the XR works, the same applies to taking half of the granules in the XR.

I think all of them are scored 4 ways for that very purpose. You could just ask for 10mg 60ct or 90ct?