Buy ritalin online overnight delivery to your home. Ritalin is used to treat attention deficit hyperactivity disorder – ADHD . It works by changing the amounts of certain natural substances in the brain. Methylphenidate belongs to a class of drugs known as stimulants. It can help increase your ability to pay attention, stay focused on an activity, and control behavior problems. It may also help you to organize your tasks and improve listening skills. This medication is also used to treat a certain sleep disorder (narcolepsy).