special subjects
Overview of Dietary Supplements
Purity and Standardization
Other areas of concern are the purity and standardization of supplements. Supplements, unlike drugs, are not regulated to ensure that they are pure or that they contain the ingredients or the amount of active ingredient they claim to contain. As a result, the supplement may contain other substances that may be inert or harmful, including, in some cases, prescription or nonprescription drugs, natural toxins, bacteria, pesticides, unapproved dyes, and even dangerous substances such as heavy metals, including lead and mercury. The amount of active ingredient in a dose of a supplement may vary, especially when whole herbs are ground or made into extracts to produce a tablet, capsule, or solution. The buyer is at risk of getting less, more, or, in some cases, none of the active ingredient in a supplement. Standardization requires that each individual dosage form of the product contain a precise amount of its active ingredient or ingredients. However, most herbal products are mixtures of several substances, and which ingredient is the most active is not always known. Therefore, determining which ingredient or ingredients should be considered active and thus subject to standardization can be difficult. Some supplements, particularly those produced in Europe, have been standardized and may include a designation of standardization on the label. Advice on how to choose a pure, standardized product varies from expert to expert. Most experts recommend buying from a well-known manufacturer, and many recommend buying products made in Germany because oversight of supplements is stricter there than in the United States. Although the content of a supplement is not standardized, the way in which it is manufactured has been standardized. In 2007, the Food and Drug Administration (FDA) created current good manufacturing practices (GMPs) that standardize the manufacturing, packaging, labeling, and storing of dietary supplements. These GMPs help ensure the quality of dietary supplements and help protect the public health. 