In 1994, the US Congress passed the Dietary Supplement and Health Education Act (DSHEA). This legislative act defined a dietary supplement as a product (other than tobacco) that is intended to supplement the diet; contain one or more dietary ingredients (including vitamins; minerals; herbs or other botanicals; amino acids; and other substances) or their constituents; is intended to be taken by mouth as a pill, capsule, tablet, or liquid; and is labeled on the front panel as being a dietary supplement. Under this law, supplements can be marketed without proof of safety or efficacy as long as no claim is made for their use in the diagnosis, treatment, cure, or prevention of disease. Manufacturers can, however, make “structure and function” claims that a product enhances a normal body function or state. For example, saw palmetto can be marketed to support urinary tract health but not to treat benign prostatic hyperplasia. In contrast to prescription medications, which must be proven safe, the US Food and Drug Administration (FDA) must first prove that an HDS is unsafe before a product is taken off the market. In 2006, the US Congress passed the Dietary Supplement and Nonprescription Drug Consumer Protection Act, which updated DSHEA so that dietary supplement producers were responsible for reporting serious adverse events related to their products. In addition, in 2007, the FDA published current good manufacturing practice guidelines, including requirements for manufacturers to test products to ensure product quality, confirm the absence of some contaminants, verify accuracy of labeling, maintain minimum standards for manufacturing and packing, monitor adverse event reports, and make all records available for FDA inspection. However, these guidelines are nonbinding on the manufacturer. Since 2007, the FDA has increased inspections of HDS manufacturers and enforcement of regulations. Other countries, including Canada, Australia, and Japan, as well as the European Union, have stricter policies on the licensure and marketing of HDS. Patients should be advised to follow certain guidelines when using HDS (Table e4–1). In 2019, the FDA reported that they will be updating the regulation of HDS to continue to promote safety, quality, and efficacy.