A generic drug is one that is created to be exactly the same as a drug that has already received approval. And they can be used as a substitute for a brand-name drug. They are designed to be as effective as brand-name drugs in terms of dosage, safety, potency, route, quality and performance, as well as intended use. The similarities between a generic drug and a brand-name drug help to prove that a generic works just as well and provides as much clinical benefit as a brand-name drug.