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Generic Drug

A medication that contains the same active ingredient, dosage, and form as a brand-name drug, approved after the original's patent expires — typically costing 80-95% less.

How It Works

Generic drugs must prove bioequivalence to the brand-name drug through an Abbreviated New Drug Application (ANDA). The FDA requires that generics perform the same way in the body — same active ingredient, same strength, same dosage form, same route of administration. Inactive ingredients (fillers, binders, colors) may differ, which is why a generic pill may look different from the brand. Generic drugs account for about 90% of all prescriptions filled in the U.S. but only about 18% of total drug spending — a testament to how much cheaper they are. Every dollar spent on generic drugs saves the U.S. healthcare system approximately $8.50 compared to brand-name prices.

Related Terms

  • Abbreviated New Drug Application (ANDA)The FDA application pathway for generic drugs, which requires proving bioequivalence to the brand-name drug rather than repeating full clinical trials.
  • BioequivalenceA regulatory standard proving that a generic drug delivers the same amount of active ingredient to the bloodstream at the same rate as the brand-name drug.
  • Patent ExpirationThe date when a drug's patent protection ends, allowing generic or biosimilar manufacturers to produce competing versions.

About This Definition

This definition is part of the DrugPrice Drug Pricing Glossary34 terms explaining how prescription drug pricing works in the United States. All definitions are written in plain language for patients, caregivers, journalists, and healthcare professionals.