A generic drug is the same as ain dosage, safety, , how it is taken, quality, performance, and intended use. Before approving a generic , FDA requires many rigorous tests and procedures to assure that the generic drug can be substituted for the . The FDA bases evaluations of substitutability, or "therapeutic equivalence," of generic drugs on scientific evaluations. By law, a generic must contain the identical amounts of the same (s) as the brand name product. products evaluated as "therapeutically equivalent" can be expected to have equal effect and no difference when substituted for the brand name product.