The Dietary Supplement Health Education Act (DSHEA) of 1994 defines a dietary supplement as
Dietary supplements are the most commonly used complementary and alternative therapies in the world. They are widely available, relatively inexpensive and can be purchased without the need to visit a healthcare practitioner. Everywhere in the world dietary supplements are regulated differently than drugs. In general, there are quality control and manufacturing regulations, but not regulations ensuring the standardization of active ingredients or their efficacy.