How long does it take for Concerta to start working.

Maezinha,
Concerta takes about 2-3 weeks before you start to notice any real change. Here are some other things you can do to help the medication be more effective for you: 1) make sure you get plenty of rest because the medicine is designed to make you feel more tired at the end of the day so your body can rest; 2) avoid alcohol consumption because it tends to slow down the medication's effects; and 3) decrease your caffeine intake because it will make you exhibit increased agitation and irritability--- don't forget that most teas, choclate, and some candies contain caffeine just like sodas and coffee! Hope this helps.