The distribution of medicine in the United States is based on a two-class system: prescription and nonprescription medicines. A nonprescription, or over-the-counter (OTC) drug is one that the U.S. Food and Drug Administration (FDA) has found to be safe and effective for direct consumer use based on the label instructions and warnings. FDA requires a wider margin of safety for nonprescription medicines than for prescription drugs.
Safe, effective, and widely available, OTC medicines play a vital and cost-effective role in our nation’s healthcare system. FDA has subjected all OTC drugs to safety and effectiveness reviews since the 1970s.