As of 2014, the United States Food and Drug Administration has not developed a formal definition for the meaning of the term "natural" when used on a label. However, the FDA doesn't file complaints against companies that use the term for substances that are free of added colors, artificial flavors and synthetic substances.
CBS News reports that consumers generally believe that the label "natural" means "healthier" and that items with this label contain no artificial ingredients, genetically modified organisms or pesticides. Kristin Kirkpatrick, a registered dietician, points out that since there is no formal definition of the term "natural," any manufacturer can label any item as "natural." Kirkpatrick goes on to say that even if a product is actually "natural," that doesn't necessarily mean it's healthy. Many unhealthy foods and substances are all-natural.
The FDA has warned consumers about manufacturers marketing weight-loss supplements that contain undisclosed drugs and chemicals. These products are often labelled as being "all natural." For example, Ja Dera 100% Natural Weight Loss Supplement was found to contain the drug sibutramine, which wasn't listed as an ingredient and is potentially harmful. The FDA has a list of all supplements that have been found to contain undisclosed drugs on its website, but the organization isn't able to test all supplements that are offered for sale.