The U.S. Food and Drug Administration's sign-off that a specific drug, at a specific dose and form, is safe and effective for a specific use, made under reviewed manufacturing standards. Approval is tied to the exact product, which is why a compounded copy or a different salt form is not "FDA-approved" even if it contains a similar molecule. It's the strongest single quality signal in the whole system.
Related terms: Branded drug · Compounded medication · Off-label prescribing · FDA drug shortage list