Focalin XR is a fast-acting medication. It will start to work within 30 minutes of taking a dose and last up to 12 hours. In general, you should take Focalin XR in the morning so that its ingredients can help manage the symptoms of attention deficit hyperactivity disorder (ADHD) throughout the day. Doctors generally prescribe Focalin XR along with ADHD treatments in the form of psychological and educational therapy. Your doctor will help you determine the best dosage and schedule for taking Focalin XR to best help treat your symptoms.