Buy Ritalin 20mg Online Commonly ritalin 20mg is used to treat ADHD.Ritalin 20mg is used to treat and manage various symptoms of attention deficit hyperactivity disorder controlling actions, and maintaining abusive language. Retain 20mg use regularly can affect directly your brain. Methylphenidate belongs to a class of stimulants. It can help to active your activity and pay attention etc. It is also an active pill.