The U.S. Food and Drug Administration requires all drug manufacturers to place unique imprints on all prescription and over-the-counter pills so that patients, health care providers and law enforcement officials can safely identify them, states Drugs.com. The regulations apply to FDA-approved drugs, homeopathic products and biological drugs.
Drugs.com and WebMD provide free pill identification tools, which allow people to search using color, imprint and shape to identify pills and locate drug dosage and contraindication information, their websites show. Some nonprescription pills, such as vitamins, energy pills and herbal compounds, bear no imprints because they don't meet the FDA's definition of drugs, states Drugs.com.
The U.S. National Library of Medicine provides a database of drug identification information for more than 200,000 unique drug names and their synonyms.