What distinguishes generic drugs from brand name drugs?

Generic drugs and brand name drugs are typically distinguished by the fact that they contain the same active ingredients but may have different non-medicinal ingredients, which can affect the drug's stability, absorption, and overall effectiveness. The active ingredient is the component that provides the therapeutic effect, and in the case of generic drugs, they must demonstrate bioequivalence to the brand name counterpart. This means that they must work in the same way and provide the same clinical benefit, even though the inactive components—such as fillers, binders, and coloring agents—can differ. These non-medicinal ingredients may impact the drug's appearance, shelf life, or how it is processed in the body, but they do not change the therapeutic efficacy of the drug. Thus, the distinction lies in these differences in non-active components while maintaining core therapeutic equivalency.