Dexedrine tablets can last from 4-6 hours and are taken 2-3 times per day.

How long does 20 mg dextroamphetamine last?

Dextroamphetamine (Dexedrine Spansule): 6-8 hours.

How long does Dexamphetamine work for?

Dexedrine (dextroamphetamine): Dexedrine becomes effective within 30 minutes to one hour. It is available in short-acting tablets, which are effective for about four to six hours. Extended-release capsules of Dexedrine are called Spansules and are effective for approximately eight to 10 hours.