"i take 10 mg generic ritalin as needed. it gets me moving and i can focus a little better. i already have hair thinning and the doc warned me that this is a known side effect for some. however, i don&#039;t know if the ritalin contributes to my hair loss or not. for me, i need to take it about 2 hours after breakfast for it to work. then it lasts about 4 hours. i probably need a script to take this twice a day instead of once."