Ritalin is methylphenidate rather than amphetamine. It is a short acting tablet, lasting 2 – 4 hours with an onset of 30 minutes. There is risk of buzz and of abuse, but like dexedrine tablets, it can be helpful for university students with a late lab or a term paper. They typically would use it once or twice a week. If they need evening benefit more often than that, I’m going to recommend a longer acting medication or a topup at lunch even with a long lasting medication. ritalin short acting tablets comes in 10 and 20 mg. and milligram for milligram, it needs about twice as many milligrams than the effective dose of dexedrine.