Modafinil and Armodafinil both are prescription medication to treat excessive daytime sleepiness associated with sleep like epilepsy, narcolepsy, shift work sleep disorder, obstructive sleep apnea etc. These two medication know as wake-promoting agent and both of the medication are very effective. However people who have a budget can go for Modafinil and those who wants longer lasting effect can go for Armodafinil. https://www.mymodalert.com/modafinil-vs-armodafinil/ from Mymodalert to know in details similarities and differences between Modafinil and Armodafinil.