Magnesium

Because the body becomes used to Adderall, the user may build up a tolerance to the medication.  They will not notice the same effects after a while at the same dose.  They will likely have to increase your dosage to continue to benefit from Adderall.  Some users of Adderall suggest that taking magnesium supplements along with the medication helps to reduce tolerance.

L-Tyrosine

Can increase synaptic dopamine levels in the brain.  Since L-Tyrosine is a dopamine precursor, taking it at night will theoretically replenish the dopamine depleted by daytime Adderall use.

L-Theanine

The absolute best supplement for the morning, afternoon, and night after an Adderall crash is L-Theanine.  It helps to produce GABA in the brain leading to greater recovery, slight drowsiness, alleviation of the symptoms of anxiety and depression that often times come with an Adderall crash, and finally, greater REM sleep.

5-HTP

The Serotonin-boosting effects of 5-HTP may help to improve mood and sleep.

Ashwagandha

Ashwagandha can enhance cognition, mental focus, and concentration.  It can also cause an anxiety-reducing feeling.  Additionally, it will improve mood as well as enhance athletic performance and stamina.