Two types of ingredients may be used in dietary supplements – “dietary ingredients” and “other ingredients.” The Federal Food, Drug, and Cosmetic Act (FD&C Act) defines a dietary ingredient as a vitamin; mineral; herb or other botanical; amino acid; dietary substance for use by man to supplement the diet by increasing the total dietary intake; or a concentrate, metabolite, constituent, extract, or combination of any dietary ingredient from the preceding categories.

Dietary supplements include such ingredients as vitamins, minerals, herbs, amino acids, and enzymes, and are typically marketed in forms such as tablets, capsules, softgels, gelcaps, powders, and liquids. Dietary supplements may also include other ingredients, such as fillers, binders, excipients, preservatives, sweeteners, and flavorings. These “other ingredients” are listed separately from dietary ingredients on the Supplement Facts label.