Does ritalin (methylphenidate) or adderall work immediately? how long do they take to have an effect?

ADHD: Both Adderall and Ritalin (methylphenidate) are stimulant medications used to treat add and adhd. Most people will start to notice effects from the medicine within 30 minutes of ingestion. The effects should also be noticed within the first few days- these are not medicines you need to be on for weeks before you see results.

30 to 45 minutes: Stimulant medication usually take between 30 and 45 minutes to begin having a positive effect.