"I’ve been taking a stimulant for two days, but I don’t feel more focused. How long should this medication take to work?"
Larry Silver, M.D.
Stimulants usually start to work within an hour, so it may be that your dose is too low. Stimulant doses are based on how quickly the body metabolizes the drug, not on the patient’s weight, height, or age, so there’s no way to predict the correct dose for any particular person. Doctors usually start by prescribing a low dose, say 5 mg. If one week passes with no improvement, the dose is generally increased.
Your doctor probably asked you to check in after a few days of starting the medication. If not, call anyway to report that there has been no effect.