Natural Health Products are defined (in Canada) as:
Similar definitions exist worldwide. Natural Health Products are closely related to drugs, and have begun to be regulated in order to control health claims being made by products not classified as drugs, but are taken for reasons above and beyond simple caloric intake.
In Canada, regulation of Natural Health Products falls to Health Canada, specifically the Natural Health Products Directorate.
In the United States, the U.S. Food and Drug Administration (FDA) is in charge of the regulation and safety of all natural health products.