Side Affects from Concerta | ADHD Information

I've just recently started taking Concerta 36mg (about 3 weeks ago) and I'm wondering if anybody else has experienced adverse side affects? I usually take it at 9 am and I feel good for about 2 hours and then I start getting a head ache and get tired in the afternoon. Has anyone else become tired from Concerta? Isnt concerta supposed to keep you awake and alert. Right now I currently take Concerta and it works great for me. I started taking Concerta about 3 years ago and so far it is the best of all medications I think. I take 54mg when I wake up and it works for the rest of the day. I rarely ever get headaches and I sleep just fine. Maybe you are getting tired just because of working to hard. I think you need to talk to your doctor and find out what is wrong.