In the United States, supplements are regulated by the FDA's Center for Food Safety and Applied Nutrition (CFSAN). According to the FDA, CFSAN (one of six product-oriented centers) is, "responsible for promoting and protecting the public's health by ensuring that the nation's food supply is safe, sanitary, wholesome, and honestly labeled, and that cosmetic products are safe and properly labeled." The Dietary Supplement Health and Education Act (DSHEA), which established a regulatory framework for supplement safety and labeling in 1994, also established the Office of Dietary Supplements (ODS) within the National Institutes of Health.

On June 22, 2007, the FDA issued a final rule establishing regulations for what are called "current good manufacturing practices" (cGMP) for dietary supplements. These regulations are aimed at manufacturers and include requirements for establishing quality control procedures, designing and constructing of manufacturing plants, and testing both individual ingredients and the finished product.

For many people, a great deal of confusion exists about what all this regulatory machinery actually does. A 2002 Harris poll showed that 59% of respondents believed supplements had to be approved by a government agency before they could be marketed; 68% believed that supplements had to list potential side effects on their labels; and 55% believed that supplement labels could not make claims of safety without scientific evidence. None of this is true.

When you purchase a supplement, you expect that what you have purchased will do what you expect it to do. But will it? A product review by ConsumerLab.com of 25 probiotic products (i.e. "healthy" bacteria) found that eight of the products had less than 1% of the claimed number of live bacteria.

When you purchase a supplement at a doctor's office, that clinician is responsible for not only for vetting the company for proper quality assurance, but for the impact on you, the consumer. You are not going to get anything like that from Costco or your local grocery store. Like any other consumer product, there is high-end and low-end. A professional-grade product costs more to make, costs the professional more in time and effort to maintain, and works better than the low-end crap you can buy at Wal-Mart. You get what you pay for. If you want to save money and purchases something that is possibly ineffective or worse, that your choice. When you go on your shopping spree, however, you may want to avoid supplements made in China.