Below is a statement from the FDA regarding dietary supplements:
"FDA requires dietary supplement manufacturers to test ingredients and products to ensure that consumers can rely on the accuracy of ingredient labeling on the products. Products must contain what their labels say they contain. If they do not, the products can be deemed mislabeled or adulterated, and FDA can take steps to remove them from commerce. Dietary supplement manufacturers and distributors are not required to obtain approval from FDA before marketing dietary supplements. Before a firm markets a dietary supplement, the firm is responsible for ensuring that the products it manufactures or distributes are safe, any claims made about the products are not false or misleading and that the products comply with the Federal Food, Drug, and Cosmetic Act and FDA regulations in all other respects.
FDA does inspect individual dietary supplement facilities, and those facilities' procedures and records, to ensure they are following current good manufacturing practices (CGMPs) including those regarding ingredient and product testing and labeling. However, if the FDA finds that a firm is not following required good manufacturing practices, the agency tells the firm that they must come into compliance with regulations.
During the past three years, FDA has increased targeted inspections of dietary supplement facilities specifically to check the industry's compliance with good manufacturing practices. In that interval, FDA has conducted more than 900 inspections of facilities producing supplements for the U.S. market, and issued about 150 warning letters to firms whose facilities had significant problems with their CGMPs, instructing firm operators to correct the insufficiencies in their practices.
FDA reminds consumers that they should always discuss with their doctors any plans to take any dietary supplement product before they do so."